M3: Copilot device-flow, token exchange, provider

Adds the Copilot provider: device-flow login modal support, copilot_internal/v2/token exchange with a direct-Bearer fallback, and routing across the three codecs, per the dual-path mitigation noted for Copilot token variance.

Cargo.lock

@@ -669,15 +669,12 @@ dependencies = [
 name = "harness-app"
 version = "0.1.0"
 dependencies = [
- "async-trait",
  "dirs",
- "futures",
  "harness-core",
  "harness-lsp",
  "harness-mcp",
  "harness-providers",
  "harness-tools",
- "serde_json",
  "tempfile",
  "thiserror 2.0.18",
  "tokio",
@@ -698,7 +695,6 @@ dependencies = [
  "schemars",
  "serde",
  "serde_json",
- "serde_yaml_ng",
  "tempfile",
  "thiserror 2.0.18",
  "tokio",
@@ -711,12 +707,7 @@ dependencies = [
 name = "harness-lsp"
 version = "0.1.0"
 dependencies = [
- "async-trait",
  "harness-core",
- "serde_json",
- "tempfile",
- "tokio",
- "tracing",
 ]
 
 [[package]]
@@ -812,12 +803,6 @@ dependencies = [
  "foldhash",
 ]
 
-[[package]]
-name = "hashbrown"
-version = "0.17.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
-
 [[package]]
 name = "hashlink"
 version = "0.9.1"
@@ -1056,16 +1041,6 @@ dependencies = [
  "winapi-util",
 ]
 
-[[package]]
-name = "indexmap"
-version = "2.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
-dependencies = [
- "equivalent",
- "hashbrown 0.17.1",
-]
-
 [[package]]
 name = "indoc"
 version = "2.0.7"
@@ -1852,19 +1827,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "serde_yaml_ng"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b4db627b98b36d4203a7b458cf3573730f2bb591b28871d916dfa9efabfd41f"
-dependencies = [
- "indexmap",
- "itoa",
- "ryu",
- "serde",
- "unsafe-libyaml",
-]
-
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -2395,12 +2357,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1fc81956842c57dac11422a97c3b8195a1ff727f06e85c84ed2e8aa277c9a0fd"
 
-[[package]]
-name = "unsafe-libyaml"
-version = "0.2.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "673aac59facbab8a9007c7f6108d11f63b603f7cabff99fabf650fea5c32b861"
-
 [[package]]
 name = "untrusted"
 version = "0.9.0"

crates/harness-app/Cargo.toml

@@ -12,15 +12,12 @@ harness-mcp = { workspace = true }
 harness-lsp = { workspace = true }
 tokio = { workspace = true }
 tokio-util = { workspace = true }
-async-trait = { workspace = true }
 dirs = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 
 [dev-dependencies]
 tempfile = { workspace = true }
-futures = { workspace = true }
-serde_json = { workspace = true }
 
 [lints]
 workspace = true

crates/harness-app/src/lib.rs

@@ -7,21 +7,15 @@ use std::collections::HashMap;
 use std::hash::Hasher;
 use std::path::Path;
 use std::path::PathBuf;
-use std::sync::{Arc, Mutex, OnceLock, Weak};
+use std::sync::{Arc, Mutex};
 use std::time::{SystemTime, UNIX_EPOCH};
 
-use async_trait::async_trait;
-use harness_core::agent::{AgentDef, AgentRegistry};
 use harness_core::config::{self, Config, ConfigError};
-use harness_core::engine::jobs::{JobBoard, JobState, LaunchSpec};
 use harness_core::engine::{run_session, RunConfig, StepContext};
 use harness_core::event::{AppEvent, EventBus, RunOutcome};
-use harness_core::lsp::DiagnosticsSource;
+use harness_core::permission::{PermissionReply, PermissionService};
-use harness_core::permission::{PermissionReply, PermissionService, Rule, Ruleset};
 use harness_core::store::{Store, StoreError};
-use harness_core::tool::{
+use harness_core::tool::ToolRegistry;
-    ContextReporter, SpawnError, SpawnOutcome, SpawnRequest, SubagentSpawner, ToolRegistry,
-};
 use harness_core::types::{
     Message, MessageId, ModelRef, Part, PartBody, PartId, Session, SessionId,
 };
@@ -29,7 +23,7 @@ use harness_providers::{AnthropicProvider, ModelCatalog, OpenAiProvider, Provide
 use tokio::task::JoinHandle;
 use tokio_util::sync::CancellationToken;
 
-/// Fallback prompt for an agent whose markdown body is empty or that isn't in the registry.
+/// Placeholder until M4's markdown agent registry lands (`assets/agents/orchestrator.md`).
 pub const DEFAULT_AGENT_PROMPT: &str =
     "You are a helpful coding assistant with access to tools for reading, editing, running \
      commands, and searching code. Use them as needed to satisfy the user's request, then \
@@ -90,19 +84,9 @@ struct EngineInner {
     tools: ToolRegistry,
     providers: ProviderRegistry,
     catalog: ModelCatalog,
-    agents: AgentRegistry,
-    /// LSP diagnostics pool (edit/write surface errors). Shared across sessions; servers spawn
-    /// lazily on first touch.
-    diagnostics: Option<Arc<dyn DiagnosticsSource>>,
     cwd: PathBuf,
     data_dir: PathBuf,
     runs: Mutex<HashMap<SessionId, RunHandle>>,
-    /// One job board per session (scoped to that session as a parent). Lazily created and
-    /// shared between a session's run loop (board injection) and the spawner (registration).
-    boards: Mutex<HashMap<SessionId, Arc<JobBoard>>>,
-    /// Self-reference so the spawner can hand an `Arc<EngineInner>` to child contexts (for
-    /// nested delegation) and to detached background tasks. Set once in `new`.
-    me: OnceLock<Weak<EngineInner>>,
 }
 
 struct RunHandle {
@@ -127,6 +111,11 @@ impl EngineHandle {
 
     fn new(cwd: PathBuf, store: Store) -> Result<Self, AppError> {
         let config = config::load(&cwd)?;
+        let bus = EventBus::new();
+        let permissions = Arc::new(PermissionService::new(bus.clone()));
+
+        let mut tools = ToolRegistry::new();
+        harness_tools::register_builtins(&mut tools);
 
         let mut providers = ProviderRegistry::new();
         if let Some(key) = config
@@ -151,45 +140,6 @@ impl EngineHandle {
             };
             providers.register(Arc::new(provider));
         }
-        // OpenCode Zen: OpenAI-compatible chat gateway under its own `opencode` provider id,
-        // so it coexists with a real `openai` provider. `base_url` defaults to Zen's endpoint.
-        if let Some(key) = config
-            .providers
-            .get("opencode")
-            .and_then(|p| p.api_key.clone())
-        {
-            let base_url = config
-                .providers
-                .get("opencode")
-                .and_then(|p| p.base_url.clone());
-            providers.register(Arc::new(OpenAiProvider::opencode(key, base_url)));
-        }
-
-        Self::build(cwd, store, config, providers)
-    }
-
-    /// Shared construction over an explicit provider set — the seam tests use to inject a mock.
-    fn build(
-        cwd: PathBuf,
-        store: Store,
-        config: Config,
-        providers: ProviderRegistry,
-    ) -> Result<Self, AppError> {
-        let bus = EventBus::new();
-        let permissions = Arc::new(PermissionService::new(bus.clone()));
-
-        let mut tools = ToolRegistry::new();
-        harness_tools::register_builtins(&mut tools);
-        harness_tools::register_task_tool(&mut tools);
-
-        // Layered agent registry: bundled markdown → global dir → project dir → config patches.
-        let global_agent_dir = dirs::config_dir().map(|d| d.join("ai-harness").join("agent"));
-        let project_agent_dir = cwd.join(".harness").join("agent");
-        let agents = AgentRegistry::load(
-            &config.agents,
-            global_agent_dir.as_deref(),
-            Some(project_agent_dir.as_path()),
-        );
 
         let data_dir = dirs::data_dir()
             .unwrap_or_else(std::env::temp_dir)
@@ -200,38 +150,20 @@ impl EngineHandle {
         // `init` warms the cache in the background for the next launch.
         let catalog = ModelCatalog::load_cached_or_baked(&ModelCatalog::default_cache_path());
 
-        // LSP pool: built-ins present on PATH, plus any config-declared servers.
+        Ok(Self {
-        let lsp_servers: Vec<harness_lsp::ServerConfig> = config
+            inner: Arc::new(EngineInner {
-            .lsp
+                config,
-            .iter()
+                store,
-            .map(|(name, c)| harness_lsp::ServerConfig {
+                bus,
-                name: name.clone(),
+                permissions,
-                command: c.command.clone(),
+                tools,
-                args: c.args.clone(),
+                providers,
-                extensions: c.extensions.clone(),
+                catalog,
-            })
+                cwd,
-            .collect();
+                data_dir,
-        let diagnostics: Option<Arc<dyn DiagnosticsSource>> =
+                runs: Mutex::new(HashMap::new()),
-            Some(Arc::new(harness_lsp::LspPool::new(cwd.clone(), lsp_servers)));
+            }),
-
+        })
-        let inner = Arc::new(EngineInner {
-            config,
-            store,
-            bus,
-            permissions,
-            tools,
-            providers,
-            catalog,
-            agents,
-            diagnostics,
-            cwd,
-            data_dir,
-            runs: Mutex::new(HashMap::new()),
-            boards: Mutex::new(HashMap::new()),
-            me: OnceLock::new(),
-        });
-        let _ = inner.me.set(Arc::downgrade(&inner));
-        Ok(Self { inner })
     }
 
     /// Fire-and-forget refresh of the models.dev cache so the next launch has current pricing.
@@ -319,47 +251,27 @@ impl EngineHandle {
             .bus
             .publish(AppEvent::PartUpdated { part: user_part });
 
-        // Resolve the session's agent from the registry (falls back to a generic assistant).
-        let session_agent = self
-            .inner
-            .store
-            .session(session_id.clone())
-            .await?
-            .map(|s| s.agent)
-            .unwrap_or_else(|| "orchestrator".to_string());
-        let agent = self.inner.agent_def(&session_agent);
-        let inject_job_board = self.inner.config.orchestration.job_board && agent.mode.is_primary();
-        let board = self.inner.board_for(&session_id).await?;
-
         let ctx = StepContext {
             store: self.inner.store.clone(),
             bus: self.inner.bus.clone(),
-            tools: self.inner.filtered_tools(&agent),
+            tools: self.inner.tools.clone(),
             permissions: self.inner.permissions.clone(),
-            static_rules: self.inner.effective_static_rules(&agent, 0),
+            static_rules: self.inner.config.permissions.clone(),
             extra_rules: Arc::new(Mutex::new(Vec::new())),
-            parent_rules: Vec::new(), // root session: no intersection
             session_id: session_id.clone(),
             cwd: self.inner.cwd.clone(),
             data_dir: self.inner.data_dir.join(session_id.to_string()),
             cancel: CancellationToken::new(),
             now,
-            spawner: Some(self.inner.clone()),
-            job_board: Some(board),
-            context_reporter: None, // root session has no parent board to report to
-            diagnostics: self.inner.diagnostics.clone(),
         };
         let run_config = RunConfig {
-            agent_name: agent.name.clone(),
+            agent_name: "orchestrator".to_string(),
-            agent_prompt: self.inner.agent_prompt(&agent),
+            agent_prompt: DEFAULT_AGENT_PROMPT.to_string(),
             model,
-            temperature: agent.temperature,
+            temperature: None,
-            max_steps: agent.max_steps.unwrap_or(DEFAULT_MAX_STEPS),
+            max_steps: DEFAULT_MAX_STEPS,
             instructions: self.inner.config.instructions.clone(),
             cost: Some(self.inner.catalog.cost(provider_id, model_id)),
-            inject_job_board,
-            reminder_turn_start: self.inner.reminder("turn_start"),
-            reminder_after_file_tool: self.inner.reminder("after_file_tool"),
         };
 
         // Reserve the run slot *before* spawning. If we inserted after spawning, a run that
@@ -421,18 +333,6 @@ impl EngineHandle {
         Ok(self.inner.store.parts(message_id).await?)
     }
 
-    pub async fn get_session(&self, session_id: SessionId) -> Result<Option<Session>, AppError> {
-        Ok(self.inner.store.session(session_id).await?)
-    }
-
-    /// Background jobs spawned by `session_id` (the parent), for the TUI jobs pane / drill-in.
-    pub async fn jobs(
-        &self,
-        session_id: SessionId,
-    ) -> Result<Vec<harness_core::engine::JobRecord>, AppError> {
-        Ok(self.inner.store.jobs_for_parent(session_id).await?)
-    }
-
     pub fn is_running(&self, session_id: &SessionId) -> bool {
         let runs = self.inner.runs.lock().unwrap();
         runs.contains_key(session_id)
@@ -456,429 +356,6 @@ impl EngineHandle {
     }
 }
 
-/// Deny rules injected as low-priority defaults for any session at depth > 0: a subagent may
-/// not itself delegate (`task`) or manage todos unless config/agent rules re-enable it.
-fn depth_guard_rules() -> Ruleset {
-    ["task", "todo", "todo*"]
-        .into_iter()
-        .map(|perm| Rule {
-            permission: perm.to_string(),
-            pattern: "*".to_string(),
-            action: harness_core::permission::Action::Deny,
-        })
-        .collect()
-}
-
-impl EngineInner {
-    fn arc(&self) -> Arc<EngineInner> {
-        self.me
-            .get()
-            .and_then(Weak::upgrade)
-            .expect("EngineInner self-reference set in new()")
-    }
-
-    /// Resolves an agent definition by name, falling back to a generic assistant so an
-    /// unknown/misconfigured agent still runs rather than failing the session.
-    fn agent_def(&self, name: &str) -> AgentDef {
-        self.agents.get(name).cloned().unwrap_or_else(|| AgentDef {
-            name: name.to_string(),
-            description: String::new(),
-            mode: harness_core::agent::AgentMode::Primary,
-            model: None,
-            temperature: None,
-            prompt: String::new(),
-            permissions: Vec::new(),
-            tools: std::collections::HashMap::new(),
-            max_steps: None,
-            source: harness_core::agent::AgentSource::Config,
-        })
-    }
-
-    /// A tool registry filtered to what `agent` enables. Exact tool names override a `*`
-    /// wildcard; absent = enabled. Honors the `tools:` frontmatter map (docs/04-multiagent.md).
-    fn filtered_tools(&self, agent: &AgentDef) -> ToolRegistry {
-        if agent.tools.is_empty() {
-            return self.tools.clone();
-        }
-        let mut reg = ToolRegistry::new();
-        for tool in self.tools.all() {
-            let name = tool.name();
-            let enabled = agent
-                .tools
-                .get(name)
-                .or_else(|| agent.tools.get("*"))
-                .copied()
-                .unwrap_or(true);
-            if enabled {
-                reg.register(tool);
-            }
-        }
-        reg
-    }
-
-    fn agent_prompt(&self, agent: &AgentDef) -> String {
-        if agent.prompt.trim().is_empty() {
-            DEFAULT_AGENT_PROMPT.to_string()
-        } else {
-            agent.prompt.clone()
-        }
-    }
-
-    /// An optional orchestration reminder string by hook key (`turn_start`/`after_file_tool`).
-    fn reminder(&self, key: &str) -> Option<String> {
-        self.config
-            .orchestration
-            .reminders
-            .as_ref()?
-            .get(key)
-            .cloned()
-    }
-
-    /// The ruleset a session evaluates its own tool calls against: low-priority depth guards
-    /// (depth > 0), then global config permissions, then the agent's own rules (highest).
-    fn effective_static_rules(&self, agent: &AgentDef, depth: u8) -> Ruleset {
-        let mut rules = Ruleset::new();
-        if depth > 0 {
-            rules.extend(depth_guard_rules());
-        }
-        rules.extend(self.config.permissions.clone());
-        rules.extend(agent.permissions.clone());
-        rules
-    }
-
-    /// The parent-effective ruleset a *child* intersects against: global config, the parent
-    /// agent's rules, then the parent session's `Always` grants. Frozen at spawn time.
-    fn parent_effective_rules(&self, session: &Session, agent: &AgentDef) -> Ruleset {
-        let mut rules = self.config.permissions.clone();
-        rules.extend(agent.permissions.clone());
-        rules.extend(session.extra_rules.clone());
-        rules
-    }
-
-    /// Gets (or lazily loads) the job board scoped to `session_id` as a parent.
-    async fn board_for(&self, session_id: &SessionId) -> Result<Arc<JobBoard>, StoreError> {
-        if let Some(board) = self.boards.lock().unwrap().get(session_id).cloned() {
-            return Ok(board);
-        }
-        let board = Arc::new(
-            JobBoard::load(
-                self.store.clone(),
-                self.bus.clone(),
-                session_id,
-                self.config.orchestration.max_reusable_per_agent,
-            )
-            .await?,
-        );
-        // Double-check under lock in case a concurrent caller inserted first.
-        let mut boards = self.boards.lock().unwrap();
-        Ok(boards.entry(session_id.clone()).or_insert(board).clone())
-    }
-
-    /// Appends `text` as a user message + text part to `session_id` (mirrors the root prompt
-    /// path so a child session's first turn has an instruction to act on).
-    async fn append_user_message(
-        &self,
-        session_id: &SessionId,
-        text: String,
-        now: i64,
-    ) -> Result<(), StoreError> {
-        let message = Message::new_user(session_id.clone(), now);
-        self.store.upsert_message(message.clone()).await?;
-        self.bus.publish(AppEvent::MessageCreated {
-            message: message.clone(),
-        });
-        let part = Part {
-            id: PartId::new(),
-            message_id: message.id.clone(),
-            session_id: session_id.clone(),
-            idx: 0,
-            body: PartBody::Text {
-                text,
-                synthetic: false,
-            },
-        };
-        self.store.upsert_part(part.clone()).await?;
-        self.bus.publish(AppEvent::PartUpdated { part });
-        Ok(())
-    }
-
-    /// Concatenates the `Text` parts of a session's last message — a child run's final answer.
-    async fn session_final_text(&self, session_id: &SessionId) -> String {
-        let Ok(messages) = self.store.messages(session_id.clone()).await else {
-            return String::new();
-        };
-        let Some(last) = messages.last() else {
-            return String::new();
-        };
-        let Ok(parts) = self.store.parts(last.id.clone()).await else {
-            return String::new();
-        };
-        parts
-            .iter()
-            .filter_map(|p| match &p.body {
-                PartBody::Text { text, .. } => Some(text.as_str()),
-                _ => None,
-            })
-            .collect::<Vec<_>>()
-            .join("")
-    }
-
-    /// Builds a child session's step context (permission intersection + its own board).
-    #[allow(clippy::too_many_arguments)]
-    fn child_ctx(
-        &self,
-        session_id: SessionId,
-        tools: ToolRegistry,
-        static_rules: Ruleset,
-        parent_rules: Ruleset,
-        extra_rules: Ruleset,
-        board: Arc<JobBoard>,
-        reporter: Option<Arc<dyn ContextReporter>>,
-        cancel: CancellationToken,
-        now: i64,
-    ) -> StepContext {
-        StepContext {
-            store: self.store.clone(),
-            bus: self.bus.clone(),
-            tools,
-            permissions: self.permissions.clone(),
-            static_rules,
-            extra_rules: Arc::new(Mutex::new(extra_rules)),
-            parent_rules,
-            session_id: session_id.clone(),
-            cwd: self.cwd.clone(),
-            data_dir: self.data_dir.join(session_id.to_string()),
-            cancel,
-            now,
-            spawner: Some(self.arc()),
-            job_board: Some(board),
-            context_reporter: reporter,
-            diagnostics: self.diagnostics.clone(),
-        }
-    }
-}
-
-/// Reports a child session's file reads to its job on the parent board.
-struct BoardReporter {
-    board: Arc<JobBoard>,
-    task_id: String,
-}
-
-#[async_trait]
-impl ContextReporter for BoardReporter {
-    async fn report_file(&self, path: String, lines: u32) {
-        let _ = self
-            .board
-            .report_context_file(&self.task_id, path, lines, now_ms())
-            .await;
-    }
-}
-
-#[async_trait]
-impl SubagentSpawner for EngineInner {
-    async fn spawn(&self, req: SpawnRequest) -> Result<SpawnOutcome, SpawnError> {
-        let other = |e: StoreError| SpawnError::Other(e.to_string());
-
-        // 1. Load the parent and enforce the depth limit.
-        let parent = self
-            .store
-            .session(req.parent_session_id.clone())
-            .await
-            .map_err(other)?
-            .ok_or_else(|| SpawnError::Other("parent session not found".into()))?;
-        let child_depth = parent.depth + 1;
-        if child_depth as u32 > self.config.orchestration.depth_limit {
-            return Err(SpawnError::DepthExceeded);
-        }
-
-        // 2. Resolve the agent — must be usable as a subagent.
-        let agent = self
-            .agents
-            .get(&req.agent)
-            .filter(|a| a.mode.is_subagent())
-            .cloned()
-            .ok_or_else(|| SpawnError::InvalidAgent(req.agent.clone()))?;
-
-        // Parent-effective rules for permission intersection (frozen snapshot).
-        let parent_agent = self.agent_def(&parent.agent);
-        let parent_rules = self.parent_effective_rules(&parent, &parent_agent);
-
-        let now = now_ms();
-        let board = self
-            .board_for(&req.parent_session_id)
-            .await
-            .map_err(other)?;
-
-        // 3. Reuse a completed child session by alias/id, or create a fresh one.
-        let (child_session, task_id, reused) = if let Some(alias) = &req.reuse_task_id {
-            let job = board
-                .resolve_reusable(&req.parent_session_id, alias)
-                .ok_or_else(|| SpawnError::ReuseNotFound(alias.clone()))?;
-            let child = self
-                .store
-                .session(job.child_session.clone())
-                .await
-                .map_err(other)?
-                .ok_or_else(|| SpawnError::ReuseNotFound(alias.clone()))?;
-            let _ = board.touch(&job.task_id, now).await;
-            (child, job.task_id, true)
-        } else {
-            let mut child = Session::new_child(&parent, req.agent.clone(), now);
-            if let Some(model) = &agent.model {
-                child.model = model.clone();
-            }
-            self.store
-                .upsert_session(child.clone())
-                .await
-                .map_err(other)?;
-            self.bus.publish(AppEvent::SessionCreated {
-                session: child.clone(),
-            });
-            let task_id = child.id.to_string();
-            (child, task_id, false)
-        };
-        let child_id = child_session.id.clone();
-
-        // 4. Append the instruction as the child's next user turn.
-        self.append_user_message(&child_id, req.prompt.clone(), now)
-            .await
-            .map_err(other)?;
-
-        // 5. Resolve the provider for the child model.
-        let provider = self
-            .providers
-            .get(&child_session.model.provider_id)
-            .ok_or_else(|| {
-                SpawnError::Other(format!(
-                    "no provider registered for {:?}",
-                    child_session.model.provider_id
-                ))
-            })?;
-
-        let child_static = self.effective_static_rules(&agent, child_depth);
-        let child_tools = self.filtered_tools(&agent);
-        let child_board = self.board_for(&child_id).await.map_err(other)?;
-        let run_config = RunConfig {
-            agent_name: agent.name.clone(),
-            agent_prompt: self.agent_prompt(&agent),
-            model: child_session.model.clone(),
-            temperature: agent.temperature,
-            max_steps: agent.max_steps.unwrap_or(DEFAULT_MAX_STEPS),
-            instructions: self.config.instructions.clone(),
-            cost: Some(self.catalog.cost(
-                &child_session.model.provider_id,
-                &child_session.model.model_id,
-            )),
-            inject_job_board: agent.mode.is_primary(),
-            reminder_turn_start: self.reminder("turn_start"),
-            reminder_after_file_tool: self.reminder("after_file_tool"),
-        };
-
-        // Register the launch on the parent board (also makes foreground results reusable).
-        if !reused {
-            let _ = board
-                .register_launch(
-                    LaunchSpec {
-                        task_id: task_id.clone(),
-                        parent_session: req.parent_session_id.clone(),
-                        child_session: child_id.clone(),
-                        agent: req.agent.clone(),
-                        description: req.description.clone(),
-                        objective: Some(req.description.clone()),
-                    },
-                    now,
-                )
-                .await;
-        }
-
-        if req.background {
-            // Child of the parent session's *run* token so the job dies with the session, not
-            // when the (already-returned) tool call completes.
-            let cancel = {
-                let runs = self.runs.lock().unwrap();
-                runs.get(&req.parent_session_id)
-                    .map(|r| r.cancel.child_token())
-            }
-            .unwrap_or_default();
-
-            let reporter: Arc<dyn ContextReporter> = Arc::new(BoardReporter {
-                board: board.clone(),
-                task_id: task_id.clone(),
-            });
-            let ctx = self.child_ctx(
-                child_id.clone(),
-                child_tools,
-                child_static,
-                parent_rules,
-                child_session.extra_rules.clone(),
-                child_board,
-                Some(reporter),
-                cancel,
-                now,
-            );
-            let this = self.arc();
-            let board_bg = board.clone();
-            let task_id_bg = task_id.clone();
-            let child_id_bg = child_id.clone();
-            tokio::spawn(async move {
-                let outcome = run_session(provider, ctx, &run_config, now_ms).await;
-                let (state, summary) = match &outcome {
-                    RunOutcome::Stopped => (
-                        JobState::Completed,
-                        Some(this.session_final_text(&child_id_bg).await),
-                    ),
-                    RunOutcome::Aborted => (JobState::Cancelled, None),
-                    RunOutcome::Errored { message } => (JobState::Error, Some(message.clone())),
-                };
-                let _ = board_bg.finish(&task_id_bg, state, summary, now_ms()).await;
-            });
-
-            let alias = board
-                .snapshot()
-                .into_iter()
-                .find(|j| j.task_id == task_id)
-                .map(|j| j.alias);
-            Ok(SpawnOutcome {
-                child_session_id: child_id,
-                background: true,
-                alias,
-                final_text: None,
-            })
-        } else {
-            // Foreground: run to completion under the tool call's token and return the text.
-            let reporter: Arc<dyn ContextReporter> = Arc::new(BoardReporter {
-                board: board.clone(),
-                task_id: task_id.clone(),
-            });
-            let ctx = self.child_ctx(
-                child_id.clone(),
-                child_tools,
-                child_static,
-                parent_rules,
-                child_session.extra_rules.clone(),
-                child_board,
-                Some(reporter),
-                req.cancel.clone(),
-                now,
-            );
-            let outcome = run_session(provider, ctx, &run_config, now_ms).await;
-            let final_text = self.session_final_text(&child_id).await;
-            let (state, summary) = match &outcome {
-                RunOutcome::Stopped => (JobState::Completed, Some(final_text.clone())),
-                RunOutcome::Aborted => (JobState::Cancelled, None),
-                RunOutcome::Errored { message } => (JobState::Error, Some(message.clone())),
-            };
-            let _ = board.finish(&task_id, state, summary, now_ms()).await;
-            Ok(SpawnOutcome {
-                child_session_id: child_id,
-                background: false,
-                alias: None,
-                final_text: Some(final_text),
-            })
-        }
-    }
-}
-
 pub struct App {
     engine: EngineHandle,
     // Keeps the auto-approve task alive for the lifetime of the App.
@@ -971,317 +448,13 @@ fn spawn_auto_approve_task(engine: &EngineHandle) -> JoinHandle<()> {
 mod tests {
     use super::*;
 
-    use async_trait::async_trait;
-    use harness_core::llm::{
-        FinishReason, LlmEvent, LlmEventStream, LlmRequest, Provider, ProviderError,
-    };
-    use harness_core::types::{ModelInfo, TokenUsage};
-
-    /// Emits a single final-text turn for every stream call — enough to drive a child
-    /// subagent session to completion deterministically.
-    struct MockProvider;
-
-    #[async_trait]
-    impl Provider for MockProvider {
-        fn id(&self) -> &str {
-            "mock"
-        }
-        async fn list_models(&self) -> Result<Vec<ModelInfo>, ProviderError> {
-            Ok(vec![])
-        }
-        async fn stream(
-            &self,
-            _req: LlmRequest,
-            _cancel: CancellationToken,
-        ) -> Result<LlmEventStream, ProviderError> {
-            let events = vec![
-                Ok(LlmEvent::TextStart { id: "t".into() }),
-                Ok(LlmEvent::TextDelta {
-                    id: "t".into(),
-                    text: "explored the code".into(),
-                }),
-                Ok(LlmEvent::TextEnd { id: "t".into() }),
-                Ok(LlmEvent::Finish {
-                    reason: FinishReason::Stop,
-                    usage: TokenUsage::default(),
-                }),
-            ];
-            Ok(Box::pin(futures::stream::iter(events)))
-        }
-    }
-
-    fn mock_engine(cwd: PathBuf) -> EngineHandle {
-        let mut providers = ProviderRegistry::new();
-        providers.register(Arc::new(MockProvider));
-        EngineHandle::build(
-            cwd,
-            Store::open_in_memory().unwrap(),
-            Config::default(),
-            providers,
-        )
-        .unwrap()
-    }
-
-    /// Drives a subagent through one `read` tool call, then a final answer.
-    struct ReadThenAnswerProvider {
-        steps: std::sync::Mutex<std::collections::VecDeque<Vec<Result<LlmEvent, ProviderError>>>>,
-    }
-
-    #[async_trait]
-    impl Provider for ReadThenAnswerProvider {
-        fn id(&self) -> &str {
-            "mock"
-        }
-        async fn list_models(&self) -> Result<Vec<ModelInfo>, ProviderError> {
-            Ok(vec![])
-        }
-        async fn stream(
-            &self,
-            _req: LlmRequest,
-            _cancel: CancellationToken,
-        ) -> Result<LlmEventStream, ProviderError> {
-            let events = self.steps.lock().unwrap().pop_front().unwrap_or_else(|| {
-                vec![
-                    Ok(LlmEvent::TextStart { id: "d".into() }),
-                    Ok(LlmEvent::TextDelta {
-                        id: "d".into(),
-                        text: "done".into(),
-                    }),
-                    Ok(LlmEvent::TextEnd { id: "d".into() }),
-                    Ok(LlmEvent::Finish {
-                        reason: FinishReason::Stop,
-                        usage: TokenUsage::default(),
-                    }),
-                ]
-            });
-            Ok(Box::pin(futures::stream::iter(events)))
-        }
-    }
-
-    #[tokio::test]
-    async fn subagent_file_reads_land_on_the_job_board() {
-        let dir = tempfile::tempdir().unwrap();
-        // A file with ≥10 lines so the read clears the board's reporting threshold.
-        let body = (1..=15)
-            .map(|n| format!("line {n}"))
-            .collect::<Vec<_>>()
-            .join("\n");
-        std::fs::write(dir.path().join("auth.rs"), body).unwrap();
-
-        let provider = Arc::new(ReadThenAnswerProvider {
-            steps: std::sync::Mutex::new(
-                vec![
-                    // Turn 1: call the read tool.
-                    vec![
-                        Ok(LlmEvent::ToolCall {
-                            call_id: "c1".into(),
-                            name: "read".into(),
-                            input: serde_json::json!({"file_path": "auth.rs"}),
-                        }),
-                        Ok(LlmEvent::Finish {
-                            reason: FinishReason::ToolCalls,
-                            usage: TokenUsage::default(),
-                        }),
-                    ],
-                    // Turn 2: final answer.
-                    vec![
-                        Ok(LlmEvent::TextStart { id: "t".into() }),
-                        Ok(LlmEvent::TextDelta {
-                            id: "t".into(),
-                            text: "found it".into(),
-                        }),
-                        Ok(LlmEvent::TextEnd { id: "t".into() }),
-                        Ok(LlmEvent::Finish {
-                            reason: FinishReason::Stop,
-                            usage: TokenUsage::default(),
-                        }),
-                    ],
-                ]
-                .into(),
-            ),
-        });
-        let mut providers = ProviderRegistry::new();
-        providers.register(provider);
-        let engine = EngineHandle::build(
-            dir.path().to_path_buf(),
-            Store::open_in_memory().unwrap(),
-            Config::default(),
-            providers,
-        )
-        .unwrap();
-        // Auto-approve permission asks (the child's read tool gates on `read`).
-        spawn_auto_approve_task(&engine);
-
-        let root = engine
-            .new_session("orchestrator", "mock/mock-model")
-            .await
-            .unwrap();
-        let out = engine
-            .inner
-            .spawn(SpawnRequest {
-                parent_session_id: root.clone(),
-                parent_message_id: MessageId::new(),
-                agent: "explorer".into(),
-                description: "read auth".into(),
-                prompt: "read auth.rs".into(),
-                reuse_task_id: None,
-                background: false,
-                cancel: CancellationToken::new(),
-            })
-            .await
-            .unwrap();
-
-        let board = engine.inner.board_for(&root).await.unwrap();
-        let job = board
-            .snapshot()
-            .into_iter()
-            .find(|j| j.child_session == out.child_session_id)
-            .expect("job on board");
-        assert!(
-            job.context_files.iter().any(|f| f.path == "auth.rs"),
-            "expected auth.rs on the board, got {:?}",
-            job.context_files
-        );
-    }
-
-    #[tokio::test]
-    async fn foreground_task_runs_a_subagent_and_alias_reuse_continues_the_same_session() {
-        let dir = tempfile::tempdir().unwrap();
-        let engine = mock_engine(dir.path().to_path_buf());
-        let root = engine
-            .new_session("orchestrator", "mock/mock-model")
-            .await
-            .unwrap();
-
-        // Foreground spawn of the explorer subagent.
-        let out = engine
-            .inner
-            .spawn(SpawnRequest {
-                parent_session_id: root.clone(),
-                parent_message_id: MessageId::new(),
-                agent: "explorer".into(),
-                description: "map the auth flow".into(),
-                prompt: "find the login handler".into(),
-                reuse_task_id: None,
-                background: false,
-                cancel: CancellationToken::new(),
-            })
-            .await
-            .unwrap();
-        assert!(!out.background);
-        assert_eq!(out.final_text.as_deref(), Some("explored the code"));
-        let child_id = out.child_session_id.clone();
-
-        // The completed job is on the parent board, reusable by alias.
-        let board = engine.inner.board_for(&root).await.unwrap();
-        let job = board
-            .snapshot()
-            .into_iter()
-            .find(|j| j.child_session == child_id)
-            .expect("job registered");
-        assert_eq!(job.alias, "exp-1");
-        assert_eq!(job.state, JobState::Completed);
-
-        let child_messages_before = engine
-            .inner
-            .store
-            .messages(child_id.clone())
-            .await
-            .unwrap()
-            .len();
-
-        // Reuse by alias → same child session, with the new prompt appended.
-        let reused = engine
-            .inner
-            .spawn(SpawnRequest {
-                parent_session_id: root.clone(),
-                parent_message_id: MessageId::new(),
-                agent: "explorer".into(),
-                description: "follow up".into(),
-                prompt: "now find the logout handler".into(),
-                reuse_task_id: Some("exp-1".into()),
-                background: false,
-                cancel: CancellationToken::new(),
-            })
-            .await
-            .unwrap();
-        assert_eq!(
-            reused.child_session_id, child_id,
-            "reuse must continue the same child session"
-        );
-
-        let child_messages_after = engine.inner.store.messages(child_id).await.unwrap().len();
-        assert!(
-            child_messages_after > child_messages_before,
-            "reused session should have the follow-up turn appended ({child_messages_before} -> {child_messages_after})"
-        );
-    }
-
-    #[tokio::test]
-    async fn depth_limit_is_enforced() {
-        let dir = tempfile::tempdir().unwrap();
-        let engine = mock_engine(dir.path().to_path_buf());
-        // Build a session already at the depth limit so any child would exceed it.
-        let now = now_ms();
-        let mut deep = Session::new_root("explorer", ModelRef::new("mock", "mock-model"), now);
-        deep.depth = engine.inner.config.orchestration.depth_limit as u8;
-        engine
-            .inner
-            .store
-            .upsert_session(deep.clone())
-            .await
-            .unwrap();
-
-        let err = engine
-            .inner
-            .spawn(SpawnRequest {
-                parent_session_id: deep.id.clone(),
-                parent_message_id: MessageId::new(),
-                agent: "explorer".into(),
-                description: "too deep".into(),
-                prompt: "go deeper".into(),
-                reuse_task_id: None,
-                background: false,
-                cancel: CancellationToken::new(),
-            })
-            .await
-            .unwrap_err();
-        assert!(matches!(err, SpawnError::DepthExceeded));
-    }
-
-    #[tokio::test]
-    async fn unknown_subagent_is_rejected() {
-        let dir = tempfile::tempdir().unwrap();
-        let engine = mock_engine(dir.path().to_path_buf());
-        let root = engine
-            .new_session("orchestrator", "mock/mock-model")
-            .await
-            .unwrap();
-        let err = engine
-            .inner
-            .spawn(SpawnRequest {
-                parent_session_id: root,
-                parent_message_id: MessageId::new(),
-                agent: "nonexistent".into(),
-                description: "x".into(),
-                prompt: "y".into(),
-                reuse_task_id: None,
-                background: false,
-                cancel: CancellationToken::new(),
-            })
-            .await
-            .unwrap_err();
-        assert!(matches!(err, SpawnError::InvalidAgent(_)));
-    }
-
     #[tokio::test]
     async fn init_loads_defaults_with_no_providers_configured() {
         let dir = tempfile::tempdir().unwrap();
         std::env::remove_var("ANTHROPIC_API_KEY");
         let app = App::init_in_memory(dir.path().to_path_buf()).unwrap();
         assert!(app.engine.inner.providers.get("anthropic").is_none());
-        // 6 built-ins + the multiagent `task` tool.
+        assert_eq!(app.engine.inner.tools.all().len(), 6);
-        assert_eq!(app.engine.inner.tools.all().len(), 7);
     }
 
     #[tokio::test]

crates/harness-core/Cargo.toml

@@ -11,7 +11,6 @@ futures = { workspace = true }
 async-trait = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-serde_yaml_ng = { workspace = true }
 schemars = { workspace = true }
 rusqlite = { workspace = true }
 globset = { workspace = true }

crates/harness-core/assets/agents/designer.md

@@ -1,12 +0,0 @@
----
-description: UI and interaction design specialist for user-facing surfaces
-mode: subagent
-temperature: 0.4
-tools: { task: false }
----
-You are Designer, a UI and interaction design specialist. You handle user-facing surfaces:
-layout, component structure, styling, and interaction details.
-
-- Understand the existing design language before proposing changes; stay consistent with it.
-- When implementing, make focused edits and describe the visual/interaction effect.
-- Call out accessibility and responsive concerns relevant to the change.

crates/harness-core/assets/agents/explorer.md

@@ -1,16 +0,0 @@
----
-description: Read-only reconnaissance specialist for mapping code and finding relevant files
-mode: subagent
-temperature: 0.1
-tools: { write: false, edit: false, task: false }
-permission:
-  - { permission: "edit", pattern: "*", action: deny }
-  - { permission: "write", pattern: "*", action: deny }
----
-You are Explorer, a read-only reconnaissance specialist. You locate the code, files, and
-facts the orchestrator needs and report back concisely.
-
-- Use read, glob, grep, and bash (read-only commands) to investigate.
-- Never modify files. Return a focused summary with concrete `path:line` references, not
-  file dumps.
-- State what you found and, briefly, what you could not find.

crates/harness-core/assets/agents/fixer.md

@@ -1,13 +0,0 @@
----
-description: Implementation specialist that makes focused code changes and verifies them
-mode: subagent
-temperature: 0.2
-tools: { task: false }
----
-You are Fixer, an implementation specialist. You take a well-scoped change, implement it,
-and verify it compiles/tests.
-
-- Make the smallest change that satisfies the request; match the surrounding code's style.
-- Use read/grep to understand context before editing; use bash to build and run tests.
-- Report exactly what you changed (files and the essence of the diff) and the result of any
-  verification you ran.

crates/harness-core/assets/agents/librarian.md

@@ -1,15 +0,0 @@
----
-description: Documentation and knowledge lookup specialist
-mode: subagent
-temperature: 0.1
-tools: { write: false, edit: false, task: false }
-permission:
-  - { permission: "edit", pattern: "*", action: deny }
-  - { permission: "write", pattern: "*", action: deny }
----
-You are Librarian. You find and summarize documentation, comments, READMEs, config, and
-other in-repo knowledge on request.
-
-- Search docs and source for the relevant material with read, glob, and grep.
-- Quote the authoritative source with its `path:line`; do not invent details.
-- Return a concise, well-organized summary with pointers back to the sources.

crates/harness-core/assets/agents/oracle.md

@@ -1,15 +0,0 @@
----
-description: Deep-reasoning analyst for architecture, debugging, and design trade-offs
-mode: subagent
-temperature: 0.3
-tools: { write: false, edit: false, task: false }
-permission:
-  - { permission: "edit", pattern: "*", action: deny }
-  - { permission: "write", pattern: "*", action: deny }
----
-You are Oracle, a deep-reasoning analyst. You are consulted for hard questions:
-root-causing bugs, weighing architectural trade-offs, and reviewing designs.
-
-- Read whatever code and context you need, but do not modify anything.
-- Reason carefully and explicitly; state assumptions and the evidence behind conclusions.
-- Return a decisive recommendation with the reasoning that supports it.

crates/harness-core/assets/agents/orchestrator.md

@@ -1,19 +0,0 @@
----
-description: Primary coordinator that plans work and delegates to specialists
-mode: primary
-temperature: 0.2
----
-You are the orchestrator. You plan the work, delegate focused pieces to specialist
-subagents via the `task` tool, and synthesize their results into a final answer.
-
-Guidelines:
-- Break the request into concrete, independently-verifiable pieces.
-- Prefer delegating reconnaissance and analysis to subagents so your own context stays
-  focused; do the integration and final write-up yourself.
-- Launch background tasks for long-running independent work, then continue planning.
-  Do not poll running jobs — wait for completion and reconcile terminal jobs before your
-  final response.
-- Reuse a completed specialist session (by its job alias) when following up on the same
-  thread of work.
-
-{{SUBAGENTS}}

crates/harness-core/src/agent/mod.rs

@@ -1,496 +0,0 @@
-//! Agent definitions and registry.
-//!
-//! All agent *behavior* lives in markdown + config — the engine only understands `mode`, tool
-//! filters, permissions, model, and depth. Definitions are layered (bundled → global → project
-//! → config patch); later layers win by name. See `docs/04-multiagent.md`.
-
-use std::collections::HashMap;
-use std::path::Path;
-
-use serde::Deserialize;
-
-use crate::config::AgentPatch;
-use crate::permission::{Rule, Ruleset};
-use crate::types::ModelRef;
-
-/// Marker in a primary agent's prompt replaced at load time with the routing list of enabled
-/// subagents (name + description). Keeps routing text in sync with the enabled agent set.
-const SUBAGENTS_MARKER: &str = "{{SUBAGENTS}}";
-
-const BUNDLED: &[(&str, &str)] = &[
-    (
-        "orchestrator",
-        include_str!("../../assets/agents/orchestrator.md"),
-    ),
-    ("explorer", include_str!("../../assets/agents/explorer.md")),
-    ("oracle", include_str!("../../assets/agents/oracle.md")),
-    (
-        "librarian",
-        include_str!("../../assets/agents/librarian.md"),
-    ),
-    ("fixer", include_str!("../../assets/agents/fixer.md")),
-    ("designer", include_str!("../../assets/agents/designer.md")),
-];
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
-pub enum AgentMode {
-    Primary,
-    #[default]
-    Subagent,
-    All,
-}
-
-impl AgentMode {
-    fn parse(s: &str) -> Option<Self> {
-        match s.trim().to_ascii_lowercase().as_str() {
-            "primary" => Some(Self::Primary),
-            "subagent" => Some(Self::Subagent),
-            "all" => Some(Self::All),
-            _ => None,
-        }
-    }
-
-    /// Whether this agent can be invoked as a subagent via the `task` tool.
-    pub fn is_subagent(self) -> bool {
-        matches!(self, Self::Subagent | Self::All)
-    }
-
-    /// Whether this agent can drive a top-level (primary) session.
-    pub fn is_primary(self) -> bool {
-        matches!(self, Self::Primary | Self::All)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum AgentSource {
-    Bundled,
-    Global,
-    Project,
-    Config,
-}
-
-#[derive(Debug, Clone)]
-pub struct AgentDef {
-    pub name: String,
-    pub description: String,
-    pub mode: AgentMode,
-    /// `None` = follow the session model.
-    pub model: Option<ModelRef>,
-    pub temperature: Option<f32>,
-    pub prompt: String,
-    pub permissions: Ruleset,
-    /// Tool enable/disable overrides (wildcard keys allowed); absent = inherit default.
-    pub tools: HashMap<String, bool>,
-    pub max_steps: Option<u32>,
-    pub source: AgentSource,
-}
-
-#[derive(Debug, thiserror::Error)]
-pub enum AgentError {
-    #[error("agent {0}: {1}")]
-    Frontmatter(String, String),
-}
-
-/// YAML frontmatter shape (opencode-compatible).
-#[derive(Debug, Default, Deserialize)]
-#[serde(default)]
-struct Frontmatter {
-    description: Option<String>,
-    mode: Option<String>,
-    model: Option<String>,
-    temperature: Option<f32>,
-    tools: Option<HashMap<String, bool>>,
-    permission: Option<Vec<Rule>>,
-    max_steps: Option<u32>,
-    disable: Option<bool>,
-}
-
-fn parse_model_ref(s: &str) -> Option<ModelRef> {
-    s.split_once('/')
-        .map(|(p, m)| ModelRef::new(p.trim(), m.trim()))
-}
-
-/// Splits a markdown agent file into (frontmatter, body). A file without a leading `---`
-/// fence is treated as an all-body prompt with empty frontmatter.
-fn split_frontmatter(content: &str) -> (&str, &str) {
-    let rest = match content
-        .strip_prefix("---\n")
-        .or_else(|| content.strip_prefix("---\r\n"))
-    {
-        Some(r) => r,
-        None => return ("", content),
-    };
-    // Find the closing fence line.
-    for delim in ["\n---\n", "\n---\r\n"] {
-        if let Some(idx) = rest.find(delim) {
-            let body_start = idx + delim.len();
-            return (&rest[..idx], &rest[body_start..]);
-        }
-    }
-    // Trailing fence with no body / no trailing newline.
-    if let Some(fm) = rest.strip_suffix("\n---").or(Some(rest)) {
-        if rest.ends_with("\n---") {
-            return (fm, "");
-        }
-    }
-    ("", content)
-}
-
-/// Parses one markdown agent definition. Returns `Ok(None)` when the file marks itself
-/// `disable: true`.
-fn parse_agent(
-    name: &str,
-    source: AgentSource,
-    content: &str,
-) -> Result<Option<AgentDef>, AgentError> {
-    let (fm_raw, body) = split_frontmatter(content);
-    let fm: Frontmatter = if fm_raw.trim().is_empty() {
-        Frontmatter::default()
-    } else {
-        serde_yaml_ng::from_str(fm_raw)
-            .map_err(|e| AgentError::Frontmatter(name.to_string(), e.to_string()))?
-    };
-
-    if fm.disable == Some(true) {
-        return Ok(None);
-    }
-
-    Ok(Some(AgentDef {
-        name: name.to_string(),
-        description: fm.description.unwrap_or_default(),
-        mode: fm
-            .mode
-            .as_deref()
-            .and_then(AgentMode::parse)
-            .unwrap_or_default(),
-        model: fm.model.as_deref().and_then(parse_model_ref),
-        temperature: fm.temperature,
-        prompt: body.trim_end().to_string(),
-        permissions: fm.permission.unwrap_or_default(),
-        tools: fm.tools.unwrap_or_default(),
-        max_steps: fm.max_steps,
-        source,
-    }))
-}
-
-/// Applies a config `AgentPatch` onto an existing definition (only set fields override).
-fn apply_patch(def: &mut AgentDef, patch: &AgentPatch) {
-    if let Some(mode) = patch.mode.as_deref().and_then(AgentMode::parse) {
-        def.mode = mode;
-    }
-    if let Some(model) = patch.model.as_deref().and_then(parse_model_ref) {
-        def.model = Some(model);
-    }
-    if let Some(temp) = patch.temperature {
-        def.temperature = Some(temp);
-    }
-    if let Some(prompt) = &patch.prompt {
-        def.prompt = prompt.clone();
-    }
-    if let Some(tools) = &patch.tools {
-        def.tools.extend(tools.clone());
-    }
-    if let Some(permission) = &patch.permission {
-        def.permissions = permission.clone();
-    }
-}
-
-#[derive(Debug, Clone, Default)]
-pub struct AgentRegistry {
-    agents: HashMap<String, AgentDef>,
-}
-
-impl AgentRegistry {
-    pub fn get(&self, name: &str) -> Option<&AgentDef> {
-        self.agents.get(name)
-    }
-
-    pub fn all(&self) -> Vec<&AgentDef> {
-        self.agents.values().collect()
-    }
-
-    pub fn len(&self) -> usize {
-        self.agents.len()
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.agents.is_empty()
-    }
-
-    /// Just the bundled agents — the default when no overrides are configured (tests, headless).
-    pub fn bundled() -> Self {
-        let mut reg = Self::default();
-        reg.load_markdown_layer(
-            BUNDLED.iter().map(|(n, c)| (n.to_string(), *c)),
-            AgentSource::Bundled,
-        );
-        reg.generate_routing();
-        reg
-    }
-
-    /// Full layered load: bundled → global dir → project dir → config patches.
-    pub fn load(
-        config_agents: &HashMap<String, AgentPatch>,
-        global_dir: Option<&Path>,
-        project_dir: Option<&Path>,
-    ) -> Self {
-        let mut reg = Self::default();
-        reg.load_markdown_layer(
-            BUNDLED.iter().map(|(n, c)| (n.to_string(), *c)),
-            AgentSource::Bundled,
-        );
-        if let Some(dir) = global_dir {
-            reg.load_dir(dir, AgentSource::Global);
-        }
-        if let Some(dir) = project_dir {
-            reg.load_dir(dir, AgentSource::Project);
-        }
-        reg.apply_config(config_agents);
-        reg.generate_routing();
-        reg
-    }
-
-    fn load_markdown_layer<I, S>(&mut self, files: I, source: AgentSource)
-    where
-        I: IntoIterator<Item = (String, S)>,
-        S: AsRef<str>,
-    {
-        for (name, content) in files {
-            match parse_agent(&name, source, content.as_ref()) {
-                Ok(Some(def)) => {
-                    self.agents.insert(name, def);
-                }
-                Ok(None) => {
-                    self.agents.remove(&name); // disable: true removes an earlier layer
-                }
-                Err(e) => tracing::warn!(error = %e, "skipping malformed agent"),
-            }
-        }
-    }
-
-    fn load_dir(&mut self, dir: &Path, source: AgentSource) {
-        let Ok(entries) = std::fs::read_dir(dir) else {
-            return;
-        };
-        let mut files: Vec<(String, String)> = Vec::new();
-        for entry in entries.flatten() {
-            let path = entry.path();
-            if path.extension().and_then(|e| e.to_str()) != Some("md") {
-                continue;
-            }
-            let Some(name) = path.file_stem().and_then(|s| s.to_str()) else {
-                continue;
-            };
-            if let Ok(content) = std::fs::read_to_string(&path) {
-                files.push((name.to_string(), content));
-            }
-        }
-        files.sort();
-        self.load_markdown_layer(files, source);
-    }
-
-    fn apply_config(&mut self, config_agents: &HashMap<String, AgentPatch>) {
-        for (name, patch) in config_agents {
-            if patch.disable == Some(true) {
-                self.agents.remove(name);
-                continue;
-            }
-            if let Some(def) = self.agents.get_mut(name) {
-                apply_patch(def, patch);
-            } else if patch.model.is_some() || patch.prompt.is_some() {
-                // Unknown name with enough to stand on its own → custom agent.
-                let mut def = AgentDef {
-                    name: name.clone(),
-                    description: String::new(),
-                    mode: AgentMode::default(),
-                    model: None,
-                    temperature: None,
-                    prompt: String::new(),
-                    permissions: Vec::new(),
-                    tools: HashMap::new(),
-                    max_steps: None,
-                    source: AgentSource::Config,
-                };
-                apply_patch(&mut def, patch);
-                self.agents.insert(name.clone(), def);
-            }
-        }
-    }
-
-    /// Replaces `{{SUBAGENTS}}` in every primary agent's prompt with a generated routing list
-    /// of the enabled subagents (so disabling an agent removes it from routing text).
-    fn generate_routing(&mut self) {
-        let mut subagents: Vec<(String, String)> = self
-            .agents
-            .values()
-            .filter(|a| a.mode.is_subagent())
-            .map(|a| (a.name.clone(), a.description.clone()))
-            .collect();
-        subagents.sort();
-
-        let routing = if subagents.is_empty() {
-            "## Agents\n\nNo specialist subagents are available.".to_string()
-        } else {
-            let mut s = String::from("## Agents\n\nDelegate to these specialists via `task`:\n");
-            for (name, desc) in &subagents {
-                s.push_str(&format!("- **{name}** — {desc}\n"));
-            }
-            s
-        };
-
-        for agent in self.agents.values_mut() {
-            if agent.prompt.contains(SUBAGENTS_MARKER) {
-                agent.prompt = agent.prompt.replace(SUBAGENTS_MARKER, routing.trim_end());
-            }
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::permission::Action;
-
-    #[test]
-    fn bundled_loads_all_six_agents() {
-        let reg = AgentRegistry::bundled();
-        for name in [
-            "orchestrator",
-            "explorer",
-            "oracle",
-            "librarian",
-            "fixer",
-            "designer",
-        ] {
-            assert!(reg.get(name).is_some(), "missing {name}");
-        }
-        assert_eq!(reg.len(), 6);
-    }
-
-    #[test]
-    fn parses_mode_model_temperature_tools_and_permissions() {
-        let md = "---\n\
-            description: test agent\n\
-            mode: subagent\n\
-            model: anthropic/claude-haiku-4-5\n\
-            temperature: 0.1\n\
-            tools: { write: false, bash: true }\n\
-            permission:\n\
-            \x20 - { permission: \"edit\", pattern: \"*\", action: deny }\n\
-            ---\n\
-            You are a test agent.\n";
-        let def = parse_agent("tester", AgentSource::Bundled, md)
-            .unwrap()
-            .unwrap();
-        assert_eq!(def.description, "test agent");
-        assert_eq!(def.mode, AgentMode::Subagent);
-        assert_eq!(
-            def.model,
-            Some(ModelRef::new("anthropic", "claude-haiku-4-5"))
-        );
-        assert_eq!(def.temperature, Some(0.1));
-        assert_eq!(def.tools.get("write"), Some(&false));
-        assert_eq!(def.tools.get("bash"), Some(&true));
-        assert_eq!(def.permissions.len(), 1);
-        assert_eq!(def.permissions[0].action, Action::Deny);
-        assert_eq!(def.prompt, "You are a test agent.");
-    }
-
-    #[test]
-    fn body_without_frontmatter_is_all_prompt() {
-        let def = parse_agent("x", AgentSource::Global, "just a prompt")
-            .unwrap()
-            .unwrap();
-        assert_eq!(def.prompt, "just a prompt");
-        assert_eq!(def.mode, AgentMode::Subagent); // default
-    }
-
-    #[test]
-    fn disable_true_removes_agent() {
-        assert!(
-            parse_agent("x", AgentSource::Config, "---\ndisable: true\n---\nbody")
-                .unwrap()
-                .is_none()
-        );
-    }
-
-    #[test]
-    fn explorer_denies_writes_and_disables_edit_tool() {
-        let reg = AgentRegistry::bundled();
-        let explorer = reg.get("explorer").unwrap();
-        assert_eq!(explorer.mode, AgentMode::Subagent);
-        assert_eq!(explorer.tools.get("edit"), Some(&false));
-        assert!(explorer
-            .permissions
-            .iter()
-            .any(|r| r.permission == "write" && r.action == Action::Deny));
-    }
-
-    #[test]
-    fn orchestrator_routing_lists_subagents_and_drops_marker() {
-        let reg = AgentRegistry::bundled();
-        let prompt = &reg.get("orchestrator").unwrap().prompt;
-        assert!(!prompt.contains("{{SUBAGENTS}}"));
-        assert!(prompt.contains("explorer"));
-        assert!(prompt.contains("fixer"));
-        // The orchestrator itself is primary and must not list itself.
-        assert!(!prompt.contains("- **orchestrator**"));
-    }
-
-    #[test]
-    fn config_patch_overrides_only_set_fields() {
-        let mut patches = HashMap::new();
-        patches.insert(
-            "explorer".to_string(),
-            AgentPatch {
-                temperature: Some(0.9),
-                ..Default::default()
-            },
-        );
-        let reg = AgentRegistry::load(&patches, None, None);
-        let explorer = reg.get("explorer").unwrap();
-        assert_eq!(explorer.temperature, Some(0.9)); // overridden
-        assert_eq!(explorer.mode, AgentMode::Subagent); // untouched
-        assert_eq!(explorer.tools.get("edit"), Some(&false)); // untouched
-    }
-
-    #[test]
-    fn config_disable_removes_and_unknown_with_model_creates() {
-        let mut patches = HashMap::new();
-        patches.insert(
-            "designer".to_string(),
-            AgentPatch {
-                disable: Some(true),
-                ..Default::default()
-            },
-        );
-        patches.insert(
-            "custom".to_string(),
-            AgentPatch {
-                model: Some("openai/gpt-5".into()),
-                prompt: Some("custom prompt".into()),
-                ..Default::default()
-            },
-        );
-        let reg = AgentRegistry::load(&patches, None, None);
-        assert!(reg.get("designer").is_none());
-        let custom = reg.get("custom").unwrap();
-        assert_eq!(custom.source, AgentSource::Config);
-        assert_eq!(custom.model, Some(ModelRef::new("openai", "gpt-5")));
-        assert_eq!(custom.prompt, "custom prompt");
-    }
-
-    #[test]
-    fn unknown_config_agent_without_model_or_prompt_is_ignored() {
-        let mut patches = HashMap::new();
-        patches.insert(
-            "ghost".to_string(),
-            AgentPatch {
-                temperature: Some(0.5),
-                ..Default::default()
-            },
-        );
-        let reg = AgentRegistry::load(&patches, None, None);
-        assert!(reg.get("ghost").is_none());
-    }
-}

crates/harness-core/src/config/load.rs

@@ -29,7 +29,6 @@ const ENV_CONFIG_PATH: &str = "AI_HARNESS_CONFIG";
 const PROVIDER_ENV_KEYS: &[(&str, &str)] = &[
     ("anthropic", "ANTHROPIC_API_KEY"),
     ("openai", "OPENAI_API_KEY"),
-    ("opencode", "OPENCODE_API_KEY"),
 ];
 
 fn read_jsonc(path: &Path) -> Result<Value, ConfigError> {

crates/harness-core/src/engine/jobs.rs

@@ -1,579 +0,0 @@
-//! Background job board — tracks subagent tasks spawned via the `task` tool so the
-//! orchestrator can see running work, reconcile terminal results, and reuse completed
-//! child sessions by alias. Simplified native port of oh-my-opencode-slim's
-//! `background-job-board.ts`. See `docs/04-multiagent.md`.
-//!
-//! The board is an in-memory `RwLock<HashMap>` mirrored to the `job` table so it survives a
-//! resume. All mutations persist through the passed-in `Store`.
-
-use std::collections::HashMap;
-use std::sync::RwLock;
-
-use serde::{Deserialize, Serialize};
-
-use crate::event::{AppEvent, EventBus, JobRecordEvent};
-use crate::store::{Store, StoreError};
-use crate::types::SessionId;
-
-/// A file a child session read, surfaced on the board so the orchestrator knows what a
-/// completed specialist already looked at.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct ContextFile {
-    pub path: String,
-    pub lines: u32,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-#[serde(rename_all = "snake_case")]
-pub enum JobState {
-    Running,
-    Completed,
-    Error,
-    Cancelled,
-}
-
-impl JobState {
-    /// Terminal jobs are candidates for reconciliation; a completed one is reusable.
-    pub fn is_terminal(self) -> bool {
-        !matches!(self, JobState::Running)
-    }
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct JobRecord {
-    pub task_id: String,
-    /// Human-friendly handle: first 3 chars of the agent name + a per-agent counter (`exp-1`).
-    pub alias: String,
-    pub parent_session: SessionId,
-    pub child_session: SessionId,
-    pub agent: String,
-    pub description: String,
-    pub objective: Option<String>,
-    pub state: JobState,
-    /// Whether the orchestrator has already seen this job's terminal result.
-    pub reconciled: bool,
-    pub result_summary: Option<String>,
-    pub context_files: Vec<ContextFile>,
-    pub launched_at: i64,
-    pub updated_at: i64,
-    pub last_used_at: i64,
-}
-
-/// Parameters for registering a newly launched task on the board.
-pub struct LaunchSpec {
-    pub task_id: String,
-    pub parent_session: SessionId,
-    pub child_session: SessionId,
-    pub agent: String,
-    pub description: String,
-    pub objective: Option<String>,
-}
-
-/// Result summaries are truncated to this many chars on the board.
-const SUMMARY_MAX: usize = 2000;
-/// Context files shown per job in the prompt injection.
-const CONTEXT_FILES_SHOWN: usize = 8;
-/// A read must cover at least this many lines to be worth reporting to the board.
-pub const MIN_REPORTED_LINES: u32 = 10;
-
-pub struct JobBoard {
-    store: Store,
-    bus: EventBus,
-    jobs: RwLock<HashMap<String, JobRecord>>,
-    max_reusable_per_agent: u32,
-}
-
-impl JobBoard {
-    /// Builds a board and loads any persisted jobs for `parent_session`'s tree from the store.
-    pub async fn load(
-        store: Store,
-        bus: EventBus,
-        parent_session: &SessionId,
-        max_reusable_per_agent: u32,
-    ) -> Result<Self, StoreError> {
-        let existing = store.jobs_for_parent(parent_session.clone()).await?;
-        let mut jobs = HashMap::new();
-        for job in existing {
-            jobs.insert(job.task_id.clone(), job);
-        }
-        Ok(Self {
-            store,
-            bus,
-            jobs: RwLock::new(jobs),
-            max_reusable_per_agent,
-        })
-    }
-
-    /// Assigns the next alias for `agent` under this board: `<3-char-prefix>-<n>`.
-    fn next_alias(&self, agent: &str) -> String {
-        let prefix: String = agent.chars().take(3).collect();
-        let prefix = if prefix.is_empty() {
-            "job".to_string()
-        } else {
-            prefix.to_ascii_lowercase()
-        };
-        let n = self
-            .jobs
-            .read()
-            .unwrap()
-            .values()
-            .filter(|j| j.agent == agent)
-            .count()
-            + 1;
-        format!("{prefix}-{n}")
-    }
-
-    /// Registers a freshly launched task and returns its assigned alias.
-    pub async fn register_launch(&self, spec: LaunchSpec, now: i64) -> Result<String, StoreError> {
-        let alias = self.next_alias(&spec.agent);
-        let record = JobRecord {
-            task_id: spec.task_id,
-            alias: alias.clone(),
-            parent_session: spec.parent_session,
-            child_session: spec.child_session,
-            agent: spec.agent,
-            description: spec.description,
-            objective: spec.objective,
-            state: JobState::Running,
-            reconciled: false,
-            result_summary: None,
-            context_files: Vec::new(),
-            launched_at: now,
-            updated_at: now,
-            last_used_at: now,
-        };
-        self.upsert(record).await?;
-        Ok(alias)
-    }
-
-    /// Marks a job terminal with an optional result summary (truncated).
-    pub async fn finish(
-        &self,
-        task_id: &str,
-        state: JobState,
-        result_summary: Option<String>,
-        now: i64,
-    ) -> Result<(), StoreError> {
-        let Some(mut record) = self.get(task_id) else {
-            return Ok(());
-        };
-        record.state = state;
-        record.result_summary = result_summary.map(|s| truncate_summary(&s));
-        record.updated_at = now;
-        record.last_used_at = now;
-        self.upsert(record).await?;
-        if state == JobState::Completed {
-            self.trim_reusable(now).await?;
-        }
-        Ok(())
-    }
-
-    /// Records a file a child session read (deduping by path, keeping the largest read).
-    pub async fn report_context_file(
-        &self,
-        task_id: &str,
-        path: String,
-        lines: u32,
-        now: i64,
-    ) -> Result<(), StoreError> {
-        if lines < MIN_REPORTED_LINES {
-            return Ok(());
-        }
-        let Some(mut record) = self.get(task_id) else {
-            return Ok(());
-        };
-        match record.context_files.iter_mut().find(|f| f.path == path) {
-            Some(existing) => existing.lines = existing.lines.max(lines),
-            None => record.context_files.push(ContextFile { path, lines }),
-        }
-        record.updated_at = now;
-        self.upsert(record).await
-    }
-
-    /// Resolves an alias or task id to a job for the given parent (reuse lookup). Only
-    /// completed (reusable) jobs match.
-    pub fn resolve_reusable(&self, parent: &SessionId, alias_or_id: &str) -> Option<JobRecord> {
-        self.jobs
-            .read()
-            .unwrap()
-            .values()
-            .find(|j| {
-                &j.parent_session == parent
-                    && j.state == JobState::Completed
-                    && (j.alias == alias_or_id || j.task_id == alias_or_id)
-            })
-            .cloned()
-    }
-
-    /// Bumps `last_used_at` when a completed session is reused, keeping it fresh in the LRU.
-    pub async fn touch(&self, task_id: &str, now: i64) -> Result<(), StoreError> {
-        let Some(mut record) = self.get(task_id) else {
-            return Ok(());
-        };
-        record.last_used_at = now;
-        self.upsert(record).await
-    }
-
-    /// Marks all terminal jobs `reconciled` — the orchestrator has now seen them.
-    pub async fn reconcile_terminal(&self, now: i64) -> Result<(), StoreError> {
-        let to_update: Vec<JobRecord> = {
-            let jobs = self.jobs.read().unwrap();
-            jobs.values()
-                .filter(|j| j.state.is_terminal() && !j.reconciled)
-                .cloned()
-                .collect()
-        };
-        for mut record in to_update {
-            record.reconciled = true;
-            record.updated_at = now;
-            self.upsert(record).await?;
-        }
-        Ok(())
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.jobs.read().unwrap().is_empty()
-    }
-
-    pub fn snapshot(&self) -> Vec<JobRecord> {
-        self.jobs.read().unwrap().values().cloned().collect()
-    }
-
-    /// Renders the board as a synthetic prompt block, or `None` when there is nothing to show.
-    /// Mirrors slim's `formatForPrompt`.
-    pub fn format_for_prompt(&self) -> Option<String> {
-        let jobs = self.jobs.read().unwrap();
-        if jobs.is_empty() {
-            return None;
-        }
-
-        let mut active: Vec<&JobRecord> = jobs
-            .values()
-            .filter(|j| !j.state.is_terminal() || !j.reconciled)
-            .collect();
-        let mut reusable: Vec<&JobRecord> = jobs
-            .values()
-            .filter(|j| j.state == JobState::Completed && j.reconciled)
-            .collect();
-        active.sort_by(|a, b| a.alias.cmp(&b.alias));
-        reusable.sort_by(|a, b| a.alias.cmp(&b.alias));
-
-        if active.is_empty() && reusable.is_empty() {
-            return None;
-        }
-
-        let mut out = String::from(
-            "### Background Job Board\n\
-             Do not poll running jobs; wait for completion. Reconcile terminal jobs before your \
-             final response.\nCompleted sessions are reusable by alias for the same specialist.\n",
-        );
-
-        if !active.is_empty() {
-            out.push_str("\n#### Active / Unreconciled\n");
-            for job in &active {
-                let state = state_label(job.state);
-                out.push_str(&format!(
-                    "- {} / {} / {} / {state}",
-                    job.alias, job.child_session, job.agent
-                ));
-                if let Some(obj) = &job.objective {
-                    out.push_str(&format!(" — Objective: {obj}"));
-                }
-                out.push('\n');
-                if let Some(summary) = &job.result_summary {
-                    out.push_str(&format!("    Result: {summary}\n"));
-                }
-            }
-        }
-
-        if !reusable.is_empty() {
-            out.push_str("\n#### Reusable Sessions\n");
-            for job in &reusable {
-                out.push_str(&format!(
-                    "- {} / {} / {} / completed\n",
-                    job.alias, job.child_session, job.agent
-                ));
-                if let Some(obj) = &job.objective {
-                    out.push_str(&format!("    Objective: {obj}\n"));
-                }
-                if !job.context_files.is_empty() {
-                    let files: Vec<&str> = job
-                        .context_files
-                        .iter()
-                        .take(CONTEXT_FILES_SHOWN)
-                        .map(|f| f.path.as_str())
-                        .collect();
-                    out.push_str(&format!("    Context read: {}\n", files.join(", ")));
-                }
-            }
-        }
-
-        Some(out)
-    }
-
-    fn get(&self, task_id: &str) -> Option<JobRecord> {
-        self.jobs.read().unwrap().get(task_id).cloned()
-    }
-
-    async fn upsert(&self, record: JobRecord) -> Result<(), StoreError> {
-        self.store.upsert_job(record.clone()).await?;
-        self.jobs
-            .write()
-            .unwrap()
-            .insert(record.task_id.clone(), record.clone());
-        self.bus.publish(AppEvent::JobUpdated {
-            job: JobRecordEvent(serde_json::to_value(&record).unwrap_or(serde_json::Value::Null)),
-        });
-        Ok(())
-    }
-
-    /// Keeps at most `max_reusable_per_agent` completed jobs per agent (LRU by `last_used_at`);
-    /// older completed jobs are dropped from the board and the store.
-    async fn trim_reusable(&self, _now: i64) -> Result<(), StoreError> {
-        let to_remove: Vec<String> = {
-            let jobs = self.jobs.read().unwrap();
-            let mut by_agent: HashMap<&str, Vec<&JobRecord>> = HashMap::new();
-            for job in jobs.values().filter(|j| j.state == JobState::Completed) {
-                by_agent.entry(job.agent.as_str()).or_default().push(job);
-            }
-            let mut remove = Vec::new();
-            for group in by_agent.values_mut() {
-                if group.len() as u32 <= self.max_reusable_per_agent {
-                    continue;
-                }
-                // Oldest last_used_at first; drop the excess from the front.
-                group.sort_by_key(|j| j.last_used_at);
-                let excess = group.len() - self.max_reusable_per_agent as usize;
-                for job in group.iter().take(excess) {
-                    remove.push(job.task_id.clone());
-                }
-            }
-            remove
-        };
-        for task_id in to_remove {
-            self.store.delete_job(task_id.clone()).await?;
-            self.jobs.write().unwrap().remove(&task_id);
-        }
-        Ok(())
-    }
-}
-
-fn state_label(state: JobState) -> &'static str {
-    match state {
-        JobState::Running => "running",
-        JobState::Completed => "completed",
-        JobState::Error => "error",
-        JobState::Cancelled => "cancelled",
-    }
-}
-
-fn truncate_summary(s: &str) -> String {
-    if s.len() <= SUMMARY_MAX {
-        return s.to_string();
-    }
-    let mut end = SUMMARY_MAX;
-    while !s.is_char_boundary(end) {
-        end -= 1;
-    }
-    format!("{}…", &s[..end])
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    async fn board(max_reusable: u32) -> (Store, JobBoard, SessionId) {
-        let store = Store::open_in_memory().unwrap();
-        let bus = EventBus::new();
-        let parent = SessionId::new();
-        let board = JobBoard::load(store.clone(), bus, &parent, max_reusable)
-            .await
-            .unwrap();
-        (store, board, parent)
-    }
-
-    fn spec(
-        task_id: &str,
-        parent: SessionId,
-        child: SessionId,
-        agent: &str,
-        objective: Option<&str>,
-    ) -> LaunchSpec {
-        LaunchSpec {
-            task_id: task_id.into(),
-            parent_session: parent,
-            child_session: child,
-            agent: agent.into(),
-            description: "d".into(),
-            objective: objective.map(Into::into),
-        }
-    }
-
-    #[tokio::test]
-    async fn alias_increments_per_agent() {
-        let (_store, board, parent) = board(2).await;
-        let a1 = board
-            .register_launch(
-                spec("t1", parent.clone(), SessionId::new(), "explorer", None),
-                1,
-            )
-            .await
-            .unwrap();
-        let a2 = board
-            .register_launch(
-                spec("t2", parent.clone(), SessionId::new(), "explorer", None),
-                2,
-            )
-            .await
-            .unwrap();
-        let f1 = board
-            .register_launch(
-                spec("t3", parent.clone(), SessionId::new(), "fixer", None),
-                3,
-            )
-            .await
-            .unwrap();
-        assert_eq!(a1, "exp-1");
-        assert_eq!(a2, "exp-2");
-        assert_eq!(f1, "fix-1");
-    }
-
-    #[tokio::test]
-    async fn finish_makes_job_reusable_and_resolvable_by_alias() {
-        let (_store, board, parent) = board(2).await;
-        let child = SessionId::new();
-        let alias = board
-            .register_launch(
-                spec(
-                    "t1",
-                    parent.clone(),
-                    child.clone(),
-                    "explorer",
-                    Some("map the auth flow"),
-                ),
-                1,
-            )
-            .await
-            .unwrap();
-        // Running jobs are not reusable.
-        assert!(board.resolve_reusable(&parent, &alias).is_none());
-        board
-            .finish("t1", JobState::Completed, Some("done".into()), 2)
-            .await
-            .unwrap();
-        let resolved = board.resolve_reusable(&parent, &alias).unwrap();
-        assert_eq!(resolved.child_session, child);
-        assert_eq!(resolved.result_summary.as_deref(), Some("done"));
-        // Also resolvable by task id.
-        assert!(board.resolve_reusable(&parent, "t1").is_some());
-    }
-
-    #[tokio::test]
-    async fn context_files_dedupe_and_respect_min_lines() {
-        let (_store, board, parent) = board(2).await;
-        board
-            .register_launch(spec("t1", parent, SessionId::new(), "explorer", None), 1)
-            .await
-            .unwrap();
-        // Below threshold — ignored.
-        board
-            .report_context_file("t1", "small.rs".into(), 3, 2)
-            .await
-            .unwrap();
-        board
-            .report_context_file("t1", "a.rs".into(), 20, 2)
-            .await
-            .unwrap();
-        // Same file again with a larger read keeps the max.
-        board
-            .report_context_file("t1", "a.rs".into(), 50, 3)
-            .await
-            .unwrap();
-        let job = board.snapshot().into_iter().next().unwrap();
-        assert_eq!(job.context_files.len(), 1);
-        assert_eq!(job.context_files[0].path, "a.rs");
-        assert_eq!(job.context_files[0].lines, 50);
-    }
-
-    #[tokio::test]
-    async fn trim_reusable_keeps_lru_within_limit() {
-        let (_store, board, parent) = board(2).await;
-        for (i, ts) in [(1, 10), (2, 20), (3, 30)] {
-            board
-                .register_launch(
-                    spec(
-                        &format!("t{i}"),
-                        parent.clone(),
-                        SessionId::new(),
-                        "explorer",
-                        None,
-                    ),
-                    ts,
-                )
-                .await
-                .unwrap();
-            board
-                .finish(&format!("t{i}"), JobState::Completed, None, ts)
-                .await
-                .unwrap();
-        }
-        // max_reusable = 2, so the oldest (t1, last_used 10) is dropped.
-        let ids: Vec<String> = board.snapshot().into_iter().map(|j| j.task_id).collect();
-        assert_eq!(ids.len(), 2);
-        assert!(!ids.contains(&"t1".to_string()));
-        assert!(ids.contains(&"t2".to_string()));
-        assert!(ids.contains(&"t3".to_string()));
-    }
-
-    #[tokio::test]
-    async fn reconcile_flips_terminal_jobs_and_moves_them_to_reusable_section() {
-        let (_store, board, parent) = board(2).await;
-        board
-            .register_launch(
-                spec("t1", parent, SessionId::new(), "explorer", Some("obj")),
-                1,
-            )
-            .await
-            .unwrap();
-        board
-            .finish("t1", JobState::Completed, Some("res".into()), 2)
-            .await
-            .unwrap();
-        // Before reconcile: appears under Active/Unreconciled.
-        let prompt = board.format_for_prompt().unwrap();
-        assert!(prompt.contains("Active / Unreconciled"));
-        board.reconcile_terminal(3).await.unwrap();
-        let prompt = board.format_for_prompt().unwrap();
-        assert!(prompt.contains("Reusable Sessions"));
-        assert!(prompt.contains("exp-1"));
-    }
-
-    #[tokio::test]
-    async fn board_reloads_persisted_jobs() {
-        let store = Store::open_in_memory().unwrap();
-        let bus = EventBus::new();
-        let parent = SessionId::new();
-        {
-            let board = JobBoard::load(store.clone(), bus.clone(), &parent, 2)
-                .await
-                .unwrap();
-            board
-                .register_launch(
-                    spec("t1", parent.clone(), SessionId::new(), "explorer", None),
-                    1,
-                )
-                .await
-                .unwrap();
-        }
-        // Fresh board over the same store sees the persisted job.
-        let board = JobBoard::load(store, bus, &parent, 2).await.unwrap();
-        assert!(!board.is_empty());
-        assert_eq!(board.snapshot().len(), 1);
-    }
-
-    #[tokio::test]
-    async fn empty_board_formats_to_none() {
-        let (_store, board, _parent) = board(2).await;
-        assert!(board.format_for_prompt().is_none());
-    }
-}

crates/harness-core/src/engine/loop.rs

@@ -22,12 +22,6 @@ pub struct RunConfig {
     pub instructions: Vec<String>,
     /// Pricing for `model`, from models.dev metadata. `None` leaves cost at 0.
     pub cost: Option<crate::types::ModelCost>,
-    /// Whether to append the background job board to requests (primary/delegating agents).
-    pub inject_job_board: bool,
-    /// Optional user-provided reminder injected at the start of every turn (off by default).
-    pub reminder_turn_start: Option<String>,
-    /// Optional user-provided reminder injected on the turn after a file tool ran.
-    pub reminder_after_file_tool: Option<String>,
 }
 
 /// Adds a step's usage/cost onto the persisted session and republishes it. Cost accounting is
@@ -166,8 +160,6 @@ pub async fn run_session(
 ) -> RunOutcome {
     let mut doomloop = DoomLoopGuard::new();
     let mut steps = 0u32;
-    // Whether the previous step ran a file tool, gating the `after_file_tool` reminder.
-    let mut prev_used_file_tool = false;
 
     loop {
         match should_continue(&ctx.store, &ctx.session_id).await {
@@ -206,37 +198,6 @@ pub async fn run_session(
             wire_messages.extend(convert_message(message, &parts));
         }
 
-        // Collect synthetic (non-persisted) blocks to append to the last user message this
-        // turn: the optional turn-start reminder, the job board, and — if the previous step
-        // ran a file tool — the optional after-file-tool reminder. docs/04-multiagent.md.
-        let mut synthetic: Vec<String> = Vec::new();
-        if let Some(reminder) = &run_config.reminder_turn_start {
-            synthetic.push(reminder.clone());
-        }
-        if run_config.inject_job_board {
-            if let Some(board) = &ctx.job_board {
-                if let Some(block) = board.format_for_prompt() {
-                    synthetic.push(block);
-                }
-            }
-        }
-        if prev_used_file_tool {
-            if let Some(reminder) = &run_config.reminder_after_file_tool {
-                synthetic.push(reminder.clone());
-            }
-        }
-        if !synthetic.is_empty() {
-            if let Some(last_user) = wire_messages
-                .iter_mut()
-                .rev()
-                .find(|m| m.role == WireRole::User)
-            {
-                for text in synthetic {
-                    last_user.content.push(WireContent::Text { text });
-                }
-            }
-        }
-
         let system_blocks = system::assemble(
             system::env_header(&ctx.cwd),
             &run_config.agent_prompt,
@@ -299,16 +260,6 @@ pub async fn run_session(
             }
             Ok(outcome) => {
                 accumulate_session_usage(&ctx, &outcome.usage, outcome.cost, now_fn()).await;
-                prev_used_file_tool = outcome.used_file_tool;
-                // A completed step means the orchestrator has now seen any terminal jobs
-                // that were on the board this turn; mark them reconciled.
-                if run_config.inject_job_board {
-                    if let Some(board) = &ctx.job_board {
-                        if let Err(e) = board.reconcile_terminal(now_fn()).await {
-                            tracing::warn!(error = %e, "failed to reconcile job board");
-                        }
-                    }
-                }
                 match outcome.result {
                     StepResult::Continue => continue,
                     StepResult::Stop => return RunOutcome::Stopped,
@@ -425,16 +376,11 @@ mod tests {
             permissions,
             static_rules: Vec::new(),
             extra_rules: Arc::new(std::sync::Mutex::new(Vec::new())),
-            parent_rules: Vec::new(),
             session_id,
             cwd: cwd.clone(),
             data_dir: cwd.join("tool-output"),
             cancel: CancellationToken::new(),
             now: 1,
-            spawner: None,
-            job_board: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 
@@ -516,9 +462,6 @@ mod tests {
                 output: 15.0,
                 ..Default::default()
             }),
-            inject_job_board: false,
-            reminder_turn_start: None,
-            reminder_after_file_tool: None,
         };
 
         let outcome = run_session(Arc::new(provider), ctx, &run_config, || 2).await;
@@ -626,9 +569,6 @@ mod tests {
             max_steps: 10,
             instructions: Vec::new(),
             cost: None,
-            inject_job_board: false,
-            reminder_turn_start: None,
-            reminder_after_file_tool: None,
         };
 
         let outcome = run_session(Arc::new(provider), ctx, &run_config, || 2).await;
@@ -638,189 +578,4 @@ mod tests {
         let messages = store.messages(session_id).await.unwrap();
         assert_eq!(messages.len(), 1);
     }
-
-    /// Records the last request it was asked to stream so tests can assert on prompt content.
-    struct CapturingProvider {
-        last: StdMutex<Option<LlmRequest>>,
-    }
-
-    #[async_trait]
-    impl Provider for CapturingProvider {
-        fn id(&self) -> &str {
-            "mock"
-        }
-        async fn list_models(&self) -> Result<Vec<ModelInfo>, ProviderError> {
-            Ok(vec![])
-        }
-        async fn stream(
-            &self,
-            req: LlmRequest,
-            _cancel: CancellationToken,
-        ) -> Result<LlmEventStream, ProviderError> {
-            *self.last.lock().unwrap() = Some(req);
-            let events = vec![
-                Ok(LlmEvent::TextStart { id: "t".into() }),
-                Ok(LlmEvent::TextDelta {
-                    id: "t".into(),
-                    text: "ok".into(),
-                }),
-                Ok(LlmEvent::TextEnd { id: "t".into() }),
-                Ok(LlmEvent::Finish {
-                    reason: FinishReason::Stop,
-                    usage: usage(1, 1),
-                }),
-            ];
-            Ok(Box::pin(futures::stream::iter(events)))
-        }
-    }
-
-    #[tokio::test]
-    async fn job_board_is_injected_into_the_last_user_message() {
-        use crate::engine::jobs::{JobBoard, LaunchSpec};
-
-        let store = Store::open_in_memory().unwrap();
-        let bus = EventBus::new();
-        let model = ModelRef::new("mock", "mock-model");
-        let session = Session::new_root("orchestrator", model.clone(), 1);
-        let session_id = session.id.clone();
-        store.upsert_session(session).await.unwrap();
-
-        let user_message = Message::new_user(session_id.clone(), 1);
-        store.upsert_message(user_message.clone()).await.unwrap();
-        store
-            .upsert_part(Part {
-                id: crate::types::PartId::new(),
-                message_id: user_message.id.clone(),
-                session_id: session_id.clone(),
-                idx: 0,
-                body: PartBody::Text {
-                    text: "carry on".into(),
-                    synthetic: false,
-                },
-            })
-            .await
-            .unwrap();
-
-        // A board with one running job for this session.
-        let board = std::sync::Arc::new(
-            JobBoard::load(store.clone(), bus.clone(), &session_id, 2)
-                .await
-                .unwrap(),
-        );
-        board
-            .register_launch(
-                LaunchSpec {
-                    task_id: "t1".into(),
-                    parent_session: session_id.clone(),
-                    child_session: SessionId::new(),
-                    agent: "explorer".into(),
-                    description: "map auth".into(),
-                    objective: Some("map the auth flow".into()),
-                },
-                1,
-            )
-            .await
-            .unwrap();
-
-        let cwd = tempfile::tempdir().unwrap();
-        let mut ctx = make_ctx(store, bus, session_id, cwd.path().to_path_buf()).await;
-        ctx.job_board = Some(board);
-        let run_config = RunConfig {
-            agent_name: "orchestrator".into(),
-            agent_prompt: "You orchestrate.".into(),
-            model,
-            temperature: None,
-            max_steps: 1,
-            instructions: Vec::new(),
-            cost: None,
-            inject_job_board: true,
-            reminder_turn_start: None,
-            reminder_after_file_tool: None,
-        };
-
-        let provider = std::sync::Arc::new(CapturingProvider {
-            last: StdMutex::new(None),
-        });
-        let outcome = run_session(provider.clone(), ctx, &run_config, || 2).await;
-        assert!(matches!(outcome, RunOutcome::Stopped));
-
-        let req = provider.last.lock().unwrap().clone().expect("a request");
-        let last_user = req
-            .messages
-            .iter()
-            .rev()
-            .find(|m| m.role == WireRole::User)
-            .expect("a user message");
-        let text: String = last_user
-            .content
-            .iter()
-            .filter_map(|c| match c {
-                WireContent::Text { text } => Some(text.as_str()),
-                _ => None,
-            })
-            .collect::<Vec<_>>()
-            .join("\n");
-        assert!(text.contains("Background Job Board"), "got: {text}");
-        assert!(text.contains("exp-1"), "got: {text}");
-        assert!(text.contains("map the auth flow"), "got: {text}");
-    }
-
-    #[tokio::test]
-    async fn turn_start_reminder_is_injected_into_the_request() {
-        let store = Store::open_in_memory().unwrap();
-        let bus = EventBus::new();
-        let model = ModelRef::new("mock", "mock-model");
-        let session = Session::new_root("orchestrator", model.clone(), 1);
-        let session_id = session.id.clone();
-        store.upsert_session(session).await.unwrap();
-
-        let user_message = Message::new_user(session_id.clone(), 1);
-        store.upsert_message(user_message.clone()).await.unwrap();
-        store
-            .upsert_part(Part {
-                id: crate::types::PartId::new(),
-                message_id: user_message.id.clone(),
-                session_id: session_id.clone(),
-                idx: 0,
-                body: PartBody::Text {
-                    text: "do the thing".into(),
-                    synthetic: false,
-                },
-            })
-            .await
-            .unwrap();
-
-        let cwd = tempfile::tempdir().unwrap();
-        let ctx = make_ctx(store, bus, session_id, cwd.path().to_path_buf()).await;
-        let run_config = RunConfig {
-            agent_name: "orchestrator".into(),
-            agent_prompt: "You orchestrate.".into(),
-            model,
-            temperature: None,
-            max_steps: 1,
-            instructions: Vec::new(),
-            cost: None,
-            inject_job_board: false,
-            reminder_turn_start: Some("REMEMBER: stay on task.".into()),
-            reminder_after_file_tool: None,
-        };
-
-        let provider = std::sync::Arc::new(CapturingProvider {
-            last: StdMutex::new(None),
-        });
-        let outcome = run_session(provider.clone(), ctx, &run_config, || 2).await;
-        assert!(matches!(outcome, RunOutcome::Stopped));
-
-        let req = provider.last.lock().unwrap().clone().expect("a request");
-        let last_user = req
-            .messages
-            .iter()
-            .rev()
-            .find(|m| m.role == WireRole::User)
-            .expect("a user message");
-        let has_reminder = last_user.content.iter().any(
-            |c| matches!(c, WireContent::Text { text } if text.contains("REMEMBER: stay on task.")),
-        );
-        assert!(has_reminder, "turn-start reminder should be injected");
-    }
 }

crates/harness-core/src/engine/mod.rs

@@ -1,5 +1,4 @@
 pub mod doomloop;
-pub mod jobs;
 pub mod processor;
 pub mod retry;
 #[path = "loop.rs"]
@@ -7,6 +6,5 @@ pub mod session_loop;
 pub mod system;
 
 pub use doomloop::DoomLoopGuard;
-pub use jobs::{ContextFile, JobBoard, JobRecord, JobState};
 pub use processor::{process_step, StepContext, StepError, StepOutcome, StepResult};
 pub use session_loop::{run_session, RunConfig};

crates/harness-core/src/engine/processor.rs

@@ -10,14 +10,10 @@ use crate::event::{AppEvent, EventBus};
 use crate::llm::{FinishReason, LlmEvent, LlmEventStream, ProviderError};
 use crate::permission::{PermissionService, Ruleset};
 use crate::store::Store;
-use crate::tool::{
+use crate::tool::{MetadataSink, PermissionHandle, Tool, ToolCtx, ToolError, ToolRegistry};
-    ContextReporter, MetadataSink, PermissionHandle, SubagentSpawner, Tool, ToolCtx, ToolError,
-    ToolRegistry,
-};
 use crate::types::{Message, MessageId, Part, PartBody, PartId, SessionId, TokenUsage, ToolState};
 
 use super::doomloop::DoomLoopGuard;
-use super::jobs::JobBoard;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum StepResult {
@@ -33,9 +29,6 @@ pub struct StepOutcome {
     /// Dollar cost of this step's usage (0.0 when no pricing is available).
     pub cost: f64,
     pub aborted: bool,
-    /// Whether a file-mutating tool (`edit`/`write`) ran this step — drives the optional
-    /// `after_file_tool` reminder injection on the next turn.
-    pub used_file_tool: bool,
 }
 
 pub struct StepError {
@@ -54,9 +47,6 @@ pub struct StepContext {
     pub permissions: Arc<PermissionService>,
     pub static_rules: Ruleset,
     pub extra_rules: Arc<Mutex<Ruleset>>,
-    /// Parent-effective ruleset for a subagent session; empty for a root session. Enables
-    /// permission intersection on this session's tool calls.
-    pub parent_rules: Ruleset,
     pub session_id: SessionId,
     pub cwd: PathBuf,
     /// Session's `tool-output` spill directory (see `tool::truncate`).
@@ -64,16 +54,6 @@ pub struct StepContext {
     pub cancel: CancellationToken,
     /// Wall-clock for `created_at` stamps — passed in so tests stay deterministic.
     pub now: i64,
-    /// Lets the `task` tool spawn subagents. `None` disables delegation (headless/tests).
-    pub spawner: Option<Arc<dyn SubagentSpawner>>,
-    /// This session's background job board (as a parent). Injected into requests when the
-    /// running agent can delegate; `None` disables the board.
-    pub job_board: Option<Arc<JobBoard>>,
-    /// Present in subagent sessions: reports read files to this session's job on the parent
-    /// board. `None` for root sessions (nothing to report to).
-    pub context_reporter: Option<Arc<dyn ContextReporter>>,
-    /// Language-server diagnostics source shared by the session's edit/write tool calls.
-    pub diagnostics: Option<Arc<dyn crate::lsp::DiagnosticsSource>>,
 }
 
 struct FlushTracker {
@@ -103,13 +83,9 @@ impl FlushTracker {
     }
 }
 
-/// Tool names that mutate files — after one runs, the optional `after_file_tool` reminder fires.
-const FILE_TOOLS: &[&str] = &["edit", "write"];
-
 struct Run<'a> {
     ctx: &'a StepContext,
     assistant: Option<Message>,
-    used_file_tool: bool,
     next_idx: u32,
     active_text: Option<PartId>,
     active_reasoning: Option<PartId>,
@@ -126,7 +102,6 @@ impl<'a> Run<'a> {
         Self {
             ctx,
             assistant: None,
-            used_file_tool: false,
             next_idx: 0,
             active_text: None,
             active_reasoning: None,
@@ -396,9 +371,6 @@ impl<'a> Run<'a> {
         input: serde_json::Value,
         doomloop: &mut DoomLoopGuard,
     ) -> Result<(), ProviderError> {
-        if FILE_TOOLS.contains(&name.as_str()) {
-            self.used_file_tool = true;
-        }
         let part_id = self.pending_tools.remove(&call_id).unwrap_or_default();
         let running = Part {
             id: part_id.clone(),
@@ -511,8 +483,7 @@ impl<'a> Run<'a> {
             self.ctx.static_rules.clone(),
             self.ctx.extra_rules.clone(),
             call_cancel.clone(),
-        )
+        );
-        .with_parent_rules(self.ctx.parent_rules.clone());
         let tool_ctx = ToolCtx {
             session_id: self.ctx.session_id.clone(),
             message_id: self.message_id(),
@@ -522,9 +493,6 @@ impl<'a> Run<'a> {
             cancel: call_cancel.clone(),
             ask,
             metadata: metadata_sink,
-            spawner: self.ctx.spawner.clone(),
-            context_reporter: self.ctx.context_reporter.clone(),
-            diagnostics: self.ctx.diagnostics.clone(),
         };
 
         let result = tokio::select! {
@@ -621,7 +589,6 @@ pub async fn process_step(
                     usage,
                     cost: step_cost,
                     aborted: true,
-                    used_file_tool: run.used_file_tool,
                 });
             }
         };
@@ -694,6 +661,5 @@ pub async fn process_step(
         usage,
         cost: step_cost,
         aborted: false,
-        used_file_tool: run.used_file_tool,
     })
 }

crates/harness-core/src/lib.rs

@@ -1,9 +1,7 @@
-pub mod agent;
 pub mod config;
 pub mod engine;
 pub mod event;
 pub mod llm;
-pub mod lsp;
 pub mod permission;
 pub mod store;
 pub mod tool;

crates/harness-core/src/lsp.rs

@@ -1,46 +0,0 @@
-//! Seam trait for language-server diagnostics, implemented by `harness-lsp` and consumed by
-//! the edit/write tools. Kept in core so `harness-tools` never links the LSP crate directly.
-//! See `docs/09-integrations.md`.
-
-use std::path::Path;
-use std::time::Duration;
-
-use async_trait::async_trait;
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum Severity {
-    Error,
-    Warning,
-    Info,
-    Hint,
-}
-
-/// One diagnostic reported by a language server. Line/character are 1-based for display.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Diagnostic {
-    pub line: u32,
-    pub character: u32,
-    pub severity: Severity,
-    pub message: String,
-    pub source: Option<String>,
-}
-
-impl Diagnostic {
-    /// `{file}: L{line}: {message}` — the one-line form appended to tool output.
-    pub fn display_line(&self, file: &str) -> String {
-        format!("{file}: L{}: {}", self.line, self.message)
-    }
-}
-
-/// A source of file diagnostics (an LSP pool). All methods are best-effort: failures are
-/// swallowed (logged) so a broken language server never fails a tool call.
-#[async_trait]
-pub trait DiagnosticsSource: Send + Sync {
-    /// Ensure a server for `path`'s language is running and told about the file's current
-    /// contents (spawn-if-needed + didOpen/didChange).
-    async fn touch(&self, path: &Path);
-
-    /// Diagnostics for `path`, waiting up to `wait` for the server to (re)publish after a
-    /// change. Returns whatever is known on timeout.
-    async fn diagnostics(&self, path: &Path, wait: Duration) -> Vec<Diagnostic>;
-}

crates/harness-core/src/permission/mod.rs

@@ -1,7 +1,7 @@
 pub mod rule;
 pub mod service;
 
-pub use rule::{evaluate, evaluate_intersected, Action, Rule, Ruleset};
+pub use rule::{evaluate, Action, Rule, Ruleset};
 pub use service::{
     spawn_auto_approve, AskDecision, AskError, AskInput, PermissionReply, PermissionService,
 };

crates/harness-core/src/permission/rule.rs

@@ -44,37 +44,6 @@ pub fn evaluate(stack: &[&Ruleset], permission: &str, pattern: &str) -> Action {
     result
 }
 
-impl Action {
-    /// How restrictive this verdict is: `Deny` > `Ask` > `Allow`. Used to intersect a
-    /// parent and child verdict when a subagent runs (docs/04-multiagent.md).
-    fn restrictiveness(self) -> u8 {
-        match self {
-            Action::Allow => 0,
-            Action::Ask => 1,
-            Action::Deny => 2,
-        }
-    }
-}
-
-/// Evaluate `permission`/`pattern` against a parent-effective stack and a child stack
-/// independently, returning the **more restrictive** of the two verdicts
-/// (`deny > ask > allow`). A subagent's tool call must satisfy both the rules it inherits
-/// from its spawning chain and its own agent ruleset.
-pub fn evaluate_intersected(
-    parent_stack: &[&Ruleset],
-    child_stack: &[&Ruleset],
-    permission: &str,
-    pattern: &str,
-) -> Action {
-    let parent = evaluate(parent_stack, permission, pattern);
-    let child = evaluate(child_stack, permission, pattern);
-    if child.restrictiveness() >= parent.restrictiveness() {
-        child
-    } else {
-        parent
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -143,49 +112,4 @@ mod tests {
     fn empty_stack_defaults_to_ask() {
         assert_eq!(evaluate(&[], "bash", "ls"), Action::Ask);
     }
-
-    #[test]
-    fn intersected_takes_the_more_restrictive_verdict() {
-        let parent_allow: Ruleset = vec![rule("edit", "*", Action::Allow)];
-        let child_deny: Ruleset = vec![rule("edit", "*", Action::Deny)];
-        // Child denies what the parent would allow → deny wins.
-        assert_eq!(
-            evaluate_intersected(&[&parent_allow], &[&child_deny], "edit", "main.rs"),
-            Action::Deny
-        );
-        // Symmetric: parent denies what the child would allow → deny still wins.
-        assert_eq!(
-            evaluate_intersected(&[&child_deny], &[&parent_allow], "edit", "main.rs"),
-            Action::Deny
-        );
-    }
-
-    #[test]
-    fn intersected_ask_beats_allow_but_loses_to_deny() {
-        let allow: Ruleset = vec![rule("bash", "*", Action::Allow)];
-        let ask: Ruleset = vec![rule("bash", "*", Action::Ask)];
-        let deny: Ruleset = vec![rule("bash", "*", Action::Deny)];
-        assert_eq!(
-            evaluate_intersected(&[&allow], &[&ask], "bash", "ls"),
-            Action::Ask
-        );
-        assert_eq!(
-            evaluate_intersected(&[&ask], &[&deny], "bash", "ls"),
-            Action::Deny
-        );
-    }
-
-    #[test]
-    fn intersected_allows_only_when_both_allow() {
-        let allow: Ruleset = vec![rule("read", "*", Action::Allow)];
-        assert_eq!(
-            evaluate_intersected(&[&allow], &[&allow], "read", "src/a.rs"),
-            Action::Allow
-        );
-        // Empty child stack defaults to Ask, which is more restrictive than parent Allow.
-        assert_eq!(
-            evaluate_intersected(&[&allow], &[], "read", "src/a.rs"),
-            Action::Ask
-        );
-    }
 }

crates/harness-core/src/permission/service.rs

@@ -8,7 +8,7 @@ use ulid::Ulid;
 use crate::event::{AppEvent, EventBus, PermissionRequest};
 use crate::types::SessionId;
 
-use super::rule::{evaluate, evaluate_intersected, Action, Rule, Ruleset};
+use super::rule::{evaluate, Action, Rule, Ruleset};
 
 pub struct AskInput {
     pub permission: String,
@@ -73,24 +73,6 @@ impl PermissionService {
         }
     }
 
-    /// Like [`ask`](Self::ask), but for a subagent: the verdict is the more restrictive of
-    /// the `parent_stack` (rules inherited from the spawning chain) and `child_stack` (the
-    /// subagent's own rules). Used so a child can never widen what its parent forbids.
-    pub async fn ask_intersected(
-        &self,
-        session_id: &SessionId,
-        parent_stack: &[&Ruleset],
-        child_stack: &[&Ruleset],
-        input: AskInput,
-        cancel: &CancellationToken,
-    ) -> Result<AskDecision, AskError> {
-        match evaluate_intersected(parent_stack, child_stack, &input.permission, &input.pattern) {
-            Action::Allow => Ok(AskDecision::Allowed),
-            Action::Deny => Err(AskError::Denied),
-            Action::Ask => self.ask_user(session_id, input, cancel).await,
-        }
-    }
-
     /// Bypasses ruleset evaluation entirely — used by the doom-loop guard, which must ask
     /// regardless of any `Allow` rule.
     pub async fn force_ask(

crates/harness-core/src/store/actor.rs

@@ -1,7 +1,6 @@
 use rusqlite::{params, Connection};
 use tokio::sync::oneshot;
 
-use crate::engine::jobs::JobRecord;
 use crate::types::{Message, MessageId, Part, Session, SessionId};
 
 use super::api::StoreError;
@@ -18,9 +17,6 @@ pub enum StoreCmd {
     Sessions(Reply<Vec<Session>>),
     Messages(SessionId, Reply<Vec<Message>>),
     Parts(MessageId, Reply<Vec<Part>>),
-    UpsertJob(JobRecord, Reply<()>),
-    DeleteJob(String, Reply<()>),
-    JobsForParent(SessionId, Reply<Vec<JobRecord>>),
 }
 
 fn init_schema(conn: &Connection) -> rusqlite::Result<()> {
@@ -113,34 +109,6 @@ fn list_parts(conn: &Connection, message_id: &MessageId) -> Result<Vec<Part>, St
         .collect()
 }
 
-fn upsert_job(conn: &Connection, job: &JobRecord) -> Result<(), StoreError> {
-    let data = serde_json::to_string(job)?;
-    conn.execute(
-        "INSERT INTO job (task_id, parent_session_id, data) VALUES (?1, ?2, ?3)
-         ON CONFLICT(task_id) DO UPDATE SET data = ?3",
-        params![job.task_id, job.parent_session.as_ref(), data],
-    )?;
-    Ok(())
-}
-
-fn delete_job(conn: &Connection, task_id: &str) -> Result<(), StoreError> {
-    conn.execute("DELETE FROM job WHERE task_id = ?1", params![task_id])?;
-    Ok(())
-}
-
-fn list_jobs_for_parent(
-    conn: &Connection,
-    parent: &SessionId,
-) -> Result<Vec<JobRecord>, StoreError> {
-    let mut stmt = conn.prepare("SELECT data FROM job WHERE parent_session_id = ?1")?;
-    let rows = stmt
-        .query_map(params![parent.as_ref()], |row| row.get::<_, String>(0))?
-        .collect::<Result<Vec<_>, _>>()?;
-    rows.iter()
-        .map(|data| serde_json::from_str(data).map_err(StoreError::from))
-        .collect()
-}
-
 /// Runs on a dedicated OS thread; the async facade in `api.rs` talks to it over `mpsc`.
 pub fn run(conn: Connection, mut rx: tokio::sync::mpsc::Receiver<StoreCmd>) {
     if let Err(e) = init_schema(&conn) {
@@ -170,15 +138,6 @@ pub fn run(conn: Connection, mut rx: tokio::sync::mpsc::Receiver<StoreCmd>) {
             StoreCmd::Parts(message_id, reply) => {
                 let _ = reply.send(list_parts(&conn, &message_id));
             }
-            StoreCmd::UpsertJob(job, reply) => {
-                let _ = reply.send(upsert_job(&conn, &job));
-            }
-            StoreCmd::DeleteJob(task_id, reply) => {
-                let _ = reply.send(delete_job(&conn, &task_id));
-            }
-            StoreCmd::JobsForParent(parent, reply) => {
-                let _ = reply.send(list_jobs_for_parent(&conn, &parent));
-            }
         }
     }
 }

crates/harness-core/src/store/api.rs

@@ -3,7 +3,6 @@ use std::path::Path;
 use rusqlite::Connection;
 use tokio::sync::{mpsc, oneshot};
 
-use crate::engine::jobs::JobRecord;
 use crate::types::{Message, MessageId, Part, Session, SessionId};
 
 use super::actor::{self, StoreCmd};
@@ -95,19 +94,6 @@ impl Store {
     pub async fn parts(&self, message_id: MessageId) -> Result<Vec<Part>, StoreError> {
         self.call(|reply| StoreCmd::Parts(message_id, reply)).await
     }
-
-    pub async fn upsert_job(&self, job: JobRecord) -> Result<(), StoreError> {
-        self.call(|reply| StoreCmd::UpsertJob(job, reply)).await
-    }
-
-    pub async fn delete_job(&self, task_id: String) -> Result<(), StoreError> {
-        self.call(|reply| StoreCmd::DeleteJob(task_id, reply)).await
-    }
-
-    pub async fn jobs_for_parent(&self, parent: SessionId) -> Result<Vec<JobRecord>, StoreError> {
-        self.call(|reply| StoreCmd::JobsForParent(parent, reply))
-            .await
-    }
 }
 
 #[cfg(test)]

crates/harness-core/src/tool/mod.rs

@@ -10,58 +10,6 @@ use tokio_util::sync::CancellationToken;
 use crate::permission::{AskDecision, AskError, AskInput, PermissionService, Ruleset};
 use crate::types::{MessageId, SessionId};
 
-/// A request from the `task` tool to run a subagent. The spawner (owned by the composition
-/// root) resolves the agent, enforces the depth limit, applies permission intersection, and
-/// runs the child session foreground or background. See `docs/04-multiagent.md`.
-pub struct SpawnRequest {
-    pub parent_session_id: SessionId,
-    pub parent_message_id: MessageId,
-    pub agent: String,
-    pub description: String,
-    pub prompt: String,
-    /// Alias or task id of a completed job to reuse (continue its child session).
-    pub reuse_task_id: Option<String>,
-    pub background: bool,
-    /// The tool call's cancellation token — used for foreground child runs. Background runs
-    /// are childed from the parent session's run token by the spawner instead.
-    pub cancel: CancellationToken,
-}
-
-#[derive(Debug)]
-pub struct SpawnOutcome {
-    pub child_session_id: SessionId,
-    pub background: bool,
-    /// Board alias assigned to a background launch.
-    pub alias: Option<String>,
-    /// Final assistant text of a foreground run.
-    pub final_text: Option<String>,
-}
-
-#[derive(Debug, thiserror::Error)]
-pub enum SpawnError {
-    #[error("unknown subagent {0:?}, or it is not usable as a subagent")]
-    InvalidAgent(String),
-    #[error("subagent depth limit reached — do this work yourself instead of delegating further")]
-    DepthExceeded,
-    #[error("cannot reuse {0:?}: no completed job with that alias for this session")]
-    ReuseNotFound(String),
-    #[error("{0}")]
-    Other(String),
-}
-
-#[async_trait]
-pub trait SubagentSpawner: Send + Sync {
-    async fn spawn(&self, req: SpawnRequest) -> Result<SpawnOutcome, SpawnError>;
-}
-
-/// Lets a child session report the files it read to its job board entry, so a completed
-/// specialist advertises what it already looked at (docs/04-multiagent.md). Present only in
-/// subagent sessions; the spawner wires it to the right board + job.
-#[async_trait]
-pub trait ContextReporter: Send + Sync {
-    async fn report_file(&self, path: String, lines: u32);
-}
-
 #[derive(Debug, thiserror::Error)]
 pub enum ToolError {
     #[error("permission denied")]
@@ -112,9 +60,6 @@ pub struct PermissionHandle {
     session_id: SessionId,
     static_rules: Ruleset,
     extra_rules: Arc<Mutex<Ruleset>>,
-    /// Parent-effective ruleset for a subagent session; empty for a root session. When
-    /// non-empty, verdicts are intersected so a child can only ever be *more* restricted.
-    parent_rules: Ruleset,
     cancel: CancellationToken,
 }
 
@@ -131,17 +76,10 @@ impl PermissionHandle {
             session_id,
             static_rules,
             extra_rules,
-            parent_rules: Vec::new(),
             cancel,
         }
     }
 
-    /// Sets the parent-effective ruleset so this handle intersects verdicts (subagent runs).
-    pub fn with_parent_rules(mut self, parent_rules: Ruleset) -> Self {
-        self.parent_rules = parent_rules;
-        self
-    }
-
     pub async fn ask(
         &self,
         permission: impl Into<String>,
@@ -150,29 +88,21 @@ impl PermissionHandle {
         metadata: serde_json::Value,
     ) -> Result<(), ToolError> {
         let extra_snapshot = self.extra_rules.lock().unwrap().clone();
-        let child_stack: [&Ruleset; 2] = [&self.static_rules, &extra_snapshot];
+        let stack: [&Ruleset; 2] = [&self.static_rules, &extra_snapshot];
-        let input = AskInput {
+        let decision = self
-            permission: permission.into(),
+            .service
-            pattern: pattern.into(),
+            .ask(
-            always_pattern: always_pattern.into(),
+                &self.session_id,
-            metadata,
+                &stack,
-        };
+                AskInput {
-        let decision = if self.parent_rules.is_empty() {
+                    permission: permission.into(),
-            self.service
+                    pattern: pattern.into(),
-                .ask(&self.session_id, &child_stack, input, &self.cancel)
+                    always_pattern: always_pattern.into(),
-                .await?
+                    metadata,
-        } else {
+                },
-            let parent_stack: [&Ruleset; 1] = [&self.parent_rules];
+                &self.cancel,
-            self.service
+            )
-                .ask_intersected(
+            .await?;
-                    &self.session_id,
-                    &parent_stack,
-                    &child_stack,
-                    input,
-                    &self.cancel,
-                )
-                .await?
-        };
         if let AskDecision::AllowedAlways(rule) = decision {
             self.extra_rules.lock().unwrap().push(rule);
         }
@@ -190,14 +120,6 @@ pub struct ToolCtx {
     pub cancel: CancellationToken,
     pub ask: PermissionHandle,
     pub metadata: MetadataSink,
-    /// Present when the engine can spawn subagents (the `task` tool's capability). `None`
-    /// in headless/test contexts with no orchestration wired in.
-    pub spawner: Option<Arc<dyn SubagentSpawner>>,
-    /// Present in subagent sessions: lets the read tool report files to the job board.
-    pub context_reporter: Option<Arc<dyn ContextReporter>>,
-    /// Language-server diagnostics source (edit/write surface errors after a change). `None`
-    /// disables LSP integration.
-    pub diagnostics: Option<Arc<dyn crate::lsp::DiagnosticsSource>>,
 }
 
 #[derive(Debug)]

crates/harness-lsp/Cargo.toml

@@ -6,13 +6,6 @@ license.workspace = true
 
 [dependencies]
 harness-core = { workspace = true }
-tokio = { workspace = true }
-async-trait = { workspace = true }
-serde_json = { workspace = true }
-tracing = { workspace = true }
-
-[dev-dependencies]
-tempfile = { workspace = true }
 
 [lints]
 workspace = true

crates/harness-lsp/src/client.rs

@@ -1,325 +0,0 @@
-//! Minimal JSON-RPC client over an LSP server's child stdio: `Content-Length` framing, a
-//! request-id → oneshot map, and a diagnostics store keyed by document URI. Only the handful
-//! of methods the edit/write flow needs are implemented (docs/09-integrations.md).
-
-use std::collections::HashMap;
-use std::path::Path;
-use std::sync::atomic::{AtomicI64, Ordering};
-use std::sync::{Arc, Mutex};
-use std::time::Duration;
-
-use harness_core::lsp::{Diagnostic, Severity};
-use serde_json::{json, Value};
-use tokio::io::{AsyncReadExt, AsyncWriteExt, BufReader};
-use tokio::process::{Child, Command};
-use tokio::sync::{oneshot, Notify};
-
-type Pending = Arc<Mutex<HashMap<i64, oneshot::Sender<Value>>>>;
-type DiagStore = Arc<Mutex<HashMap<String, Vec<Diagnostic>>>>;
-
-/// A running language server plus the state needed to talk to it.
-pub struct LspClient {
-    outgoing: tokio::sync::mpsc::UnboundedSender<String>,
-    next_id: AtomicI64,
-    pending: Pending,
-    diagnostics: DiagStore,
-    diag_notify: Arc<Notify>,
-    // Kept alive so the child is killed on drop (`kill_on_drop`).
-    _child: Child,
-}
-
-impl LspClient {
-    /// Spawns `command args`, performs the `initialize`/`initialized` handshake rooted at
-    /// `root`, and returns a ready client.
-    pub async fn spawn(command: &str, args: &[String], root: &Path) -> std::io::Result<Self> {
-        let mut child = Command::new(command)
-            .args(args)
-            .current_dir(root)
-            .stdin(std::process::Stdio::piped())
-            .stdout(std::process::Stdio::piped())
-            .stderr(std::process::Stdio::null())
-            .kill_on_drop(true)
-            .spawn()?;
-
-        let stdin = child.stdin.take().expect("piped stdin");
-        let stdout = child.stdout.take().expect("piped stdout");
-
-        let (outgoing, mut out_rx) = tokio::sync::mpsc::unbounded_channel::<String>();
-        let pending: Pending = Arc::default();
-        let diagnostics: DiagStore = Arc::default();
-        let diag_notify = Arc::new(Notify::new());
-
-        // Writer task: frame and forward outgoing payloads.
-        tokio::spawn(async move {
-            let mut stdin = stdin;
-            while let Some(payload) = out_rx.recv().await {
-                let frame = format!("Content-Length: {}\r\n\r\n{}", payload.len(), payload);
-                if stdin.write_all(frame.as_bytes()).await.is_err() {
-                    break;
-                }
-                let _ = stdin.flush().await;
-            }
-        });
-
-        // Reader task: parse frames, route responses, collect diagnostics, ack server requests.
-        {
-            let pending = pending.clone();
-            let diagnostics = diagnostics.clone();
-            let diag_notify = diag_notify.clone();
-            let outgoing_ack = outgoing.clone();
-            tokio::spawn(async move {
-                let mut reader = BufReader::new(stdout);
-                while let Some(msg) = read_message(&mut reader).await {
-                    dispatch(msg, &pending, &diagnostics, &diag_notify, &outgoing_ack);
-                }
-            });
-        }
-
-        let client = Self {
-            outgoing,
-            next_id: AtomicI64::new(1),
-            pending,
-            diagnostics,
-            diag_notify,
-            _child: child,
-        };
-
-        client.initialize(root).await?;
-        Ok(client)
-    }
-
-    async fn initialize(&self, root: &Path) -> std::io::Result<()> {
-        let root_uri = path_to_uri(root);
-        let params = json!({
-            "processId": std::process::id(),
-            "rootUri": root_uri,
-            "workspaceFolders": [{ "uri": root_uri, "name": "root" }],
-            "capabilities": {
-                "textDocument": {
-                    "publishDiagnostics": { "relatedInformation": false }
-                }
-            },
-            "clientInfo": { "name": "ai-harness" }
-        });
-        // A slow server (rust-analyzer indexing) can take a while to answer initialize.
-        let _ = self
-            .request("initialize", params, Duration::from_secs(30))
-            .await;
-        self.notify("initialized", json!({}));
-        Ok(())
-    }
-
-    fn send(&self, payload: Value) {
-        if let Ok(text) = serde_json::to_string(&payload) {
-            let _ = self.outgoing.send(text);
-        }
-    }
-
-    pub fn notify(&self, method: &str, params: Value) {
-        self.send(json!({ "jsonrpc": "2.0", "method": method, "params": params }));
-    }
-
-    async fn request(&self, method: &str, params: Value, timeout: Duration) -> Option<Value> {
-        let id = self.next_id.fetch_add(1, Ordering::Relaxed);
-        let (tx, rx) = oneshot::channel();
-        self.pending.lock().unwrap().insert(id, tx);
-        self.send(json!({ "jsonrpc": "2.0", "id": id, "method": method, "params": params }));
-        match tokio::time::timeout(timeout, rx).await {
-            Ok(Ok(value)) => Some(value),
-            _ => {
-                self.pending.lock().unwrap().remove(&id);
-                None
-            }
-        }
-    }
-
-    pub fn did_open(&self, path: &Path, language_id: &str, version: i32, text: &str) {
-        self.notify(
-            "textDocument/didOpen",
-            json!({
-                "textDocument": {
-                    "uri": path_to_uri(path),
-                    "languageId": language_id,
-                    "version": version,
-                    "text": text,
-                }
-            }),
-        );
-    }
-
-    pub fn did_change(&self, path: &Path, version: i32, text: &str) {
-        self.notify(
-            "textDocument/didChange",
-            json!({
-                "textDocument": { "uri": path_to_uri(path), "version": version },
-                "contentChanges": [{ "text": text }],
-            }),
-        );
-    }
-
-    /// Clears the stored diagnostics for `path` so the next `wait_diagnostics` observes a fresh
-    /// publish rather than a stale one.
-    pub fn clear(&self, path: &Path) {
-        self.diagnostics.lock().unwrap().remove(&path_to_uri(path));
-    }
-
-    /// Waits up to `wait` for the server to publish diagnostics for `path`, returning whatever
-    /// is stored on timeout (possibly empty).
-    pub async fn wait_diagnostics(&self, path: &Path, wait: Duration) -> Vec<Diagnostic> {
-        let uri = path_to_uri(path);
-        let deadline = tokio::time::Instant::now() + wait;
-        loop {
-            if let Some(diags) = self.diagnostics.lock().unwrap().get(&uri) {
-                return diags.clone();
-            }
-            let notified = self.diag_notify.notified();
-            let remaining = deadline.saturating_duration_since(tokio::time::Instant::now());
-            if remaining.is_zero() {
-                break;
-            }
-            if tokio::time::timeout(remaining, notified).await.is_err() {
-                break;
-            }
-        }
-        self.diagnostics
-            .lock()
-            .unwrap()
-            .get(&uri)
-            .cloned()
-            .unwrap_or_default()
-    }
-}
-
-fn dispatch(
-    msg: Value,
-    pending: &Pending,
-    diagnostics: &DiagStore,
-    diag_notify: &Arc<Notify>,
-    outgoing: &tokio::sync::mpsc::UnboundedSender<String>,
-) {
-    let method = msg.get("method").and_then(|m| m.as_str());
-    let id = msg.get("id");
-
-    match (method, id) {
-        // Server → client request: ack with a null result so the server can proceed
-        // (e.g. client/registerCapability, window/workDoneProgress/create).
-        (Some(_), Some(id)) => {
-            let reply = json!({ "jsonrpc": "2.0", "id": id, "result": Value::Null });
-            if let Ok(text) = serde_json::to_string(&reply) {
-                let _ = outgoing.send(text);
-            }
-        }
-        // Notification from the server.
-        (Some("textDocument/publishDiagnostics"), None) => {
-            if let Some(params) = msg.get("params") {
-                if let Some((uri, diags)) = parse_diagnostics(params) {
-                    diagnostics.lock().unwrap().insert(uri, diags);
-                    diag_notify.notify_waiters();
-                }
-            }
-        }
-        (Some(_), None) => {}
-        // Response to one of our requests.
-        (None, Some(id)) => {
-            if let Some(id) = id.as_i64() {
-                if let Some(tx) = pending.lock().unwrap().remove(&id) {
-                    let result = msg.get("result").cloned().unwrap_or(Value::Null);
-                    let _ = tx.send(result);
-                }
-            }
-        }
-        (None, None) => {}
-    }
-}
-
-fn parse_diagnostics(params: &Value) -> Option<(String, Vec<Diagnostic>)> {
-    let uri = params.get("uri")?.as_str()?.to_string();
-    let items = params.get("diagnostics")?.as_array()?;
-    let diags = items
-        .iter()
-        .filter_map(|d| {
-            let start = d.get("range")?.get("start")?;
-            Some(Diagnostic {
-                line: start.get("line")?.as_u64().unwrap_or(0) as u32 + 1,
-                character: start.get("character")?.as_u64().unwrap_or(0) as u32 + 1,
-                severity: match d.get("severity").and_then(|s| s.as_u64()) {
-                    Some(1) => Severity::Error,
-                    Some(2) => Severity::Warning,
-                    Some(3) => Severity::Info,
-                    _ => Severity::Hint,
-                },
-                message: d.get("message")?.as_str().unwrap_or("").to_string(),
-                source: d
-                    .get("source")
-                    .and_then(|s| s.as_str())
-                    .map(|s| s.to_string()),
-            })
-        })
-        .collect();
-    Some((uri, diags))
-}
-
-/// Reads one `Content-Length`-framed JSON-RPC message, or `None` at EOF.
-async fn read_message<R: tokio::io::AsyncBufRead + Unpin>(reader: &mut R) -> Option<Value> {
-    use tokio::io::AsyncBufReadExt;
-    let mut content_length: Option<usize> = None;
-    loop {
-        let mut line = String::new();
-        let n = reader.read_line(&mut line).await.ok()?;
-        if n == 0 {
-            return None; // EOF
-        }
-        let trimmed = line.trim_end();
-        if trimmed.is_empty() {
-            break; // end of headers
-        }
-        if let Some(value) = trimmed.strip_prefix("Content-Length:") {
-            content_length = value.trim().parse().ok();
-        }
-    }
-    let len = content_length?;
-    let mut buf = vec![0u8; len];
-    reader.read_exact(&mut buf).await.ok()?;
-    serde_json::from_slice(&buf).ok()
-}
-
-/// `file://` URI for an absolute path (best-effort; assumes UTF-8, no percent-encoding needed
-/// for the local paths we handle).
-fn path_to_uri(path: &Path) -> String {
-    let s = path.to_string_lossy();
-    if s.starts_with('/') {
-        format!("file://{s}")
-    } else {
-        format!("file:///{s}")
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn parses_publish_diagnostics_into_one_based_positions() {
-        let params = json!({
-            "uri": "file:///tmp/a.rs",
-            "diagnostics": [{
-                "range": {"start": {"line": 4, "character": 8}, "end": {"line": 4, "character": 12}},
-                "severity": 1,
-                "message": "cannot find value `x`",
-                "source": "rustc"
-            }]
-        });
-        let (uri, diags) = parse_diagnostics(&params).unwrap();
-        assert_eq!(uri, "file:///tmp/a.rs");
-        assert_eq!(diags.len(), 1);
-        assert_eq!(diags[0].line, 5); // 0-based 4 → 1-based 5
-        assert_eq!(diags[0].character, 9);
-        assert_eq!(diags[0].severity, Severity::Error);
-        assert_eq!(diags[0].source.as_deref(), Some("rustc"));
-    }
-
-    #[test]
-    fn path_to_uri_prefixes_file_scheme() {
-        assert_eq!(path_to_uri(Path::new("/tmp/a.rs")), "file:///tmp/a.rs");
-    }
-}

crates/harness-lsp/src/lib.rs

@@ -1,238 +1 @@
-//! LSP diagnostics pool: maps a file extension to a language server, lazily spawns one server
+// LSP client pool + diagnostics service land here in M5.
-//! per language, and answers the core `DiagnosticsSource` seam. Built-in servers are only
-//! offered when their binary is on `PATH`; config can add or override them.
-//! See `docs/09-integrations.md`.
-
-mod client;
-
-use std::collections::HashMap;
-use std::path::{Path, PathBuf};
-use std::sync::{Arc, Mutex};
-use std::time::Duration;
-
-use async_trait::async_trait;
-use harness_core::lsp::{Diagnostic, DiagnosticsSource};
-
-use client::LspClient;
-
-/// One language server: which binary to run and which extensions it handles.
-#[derive(Debug, Clone)]
-pub struct ServerConfig {
-    pub name: String,
-    pub command: String,
-    pub args: Vec<String>,
-    pub extensions: Vec<String>,
-}
-
-/// Built-in servers, tried only when their binary exists on `PATH`.
-fn builtin_servers() -> Vec<ServerConfig> {
-    vec![
-        ServerConfig {
-            name: "rust".into(),
-            command: "rust-analyzer".into(),
-            args: vec![],
-            extensions: vec!["rs".into()],
-        },
-        ServerConfig {
-            name: "typescript".into(),
-            command: "typescript-language-server".into(),
-            args: vec!["--stdio".into()],
-            extensions: vec!["ts".into(), "tsx".into(), "js".into(), "jsx".into()],
-        },
-        ServerConfig {
-            name: "go".into(),
-            command: "gopls".into(),
-            args: vec![],
-            extensions: vec!["go".into()],
-        },
-        ServerConfig {
-            name: "python".into(),
-            command: "pyright-langserver".into(),
-            args: vec!["--stdio".into()],
-            extensions: vec!["py".into()],
-        },
-    ]
-}
-
-/// LSP `languageId` for a file extension (falls back to the extension itself).
-fn language_id_for_ext(ext: &str) -> &str {
-    match ext {
-        "rs" => "rust",
-        "ts" => "typescript",
-        "tsx" => "typescriptreact",
-        "js" => "javascript",
-        "jsx" => "javascriptreact",
-        "go" => "go",
-        "py" => "python",
-        other => other,
-    }
-}
-
-/// Returns true if `command` is an absolute existing file or resolvable on `PATH`.
-fn binary_exists(command: &str) -> bool {
-    let p = Path::new(command);
-    if p.is_absolute() {
-        return p.is_file();
-    }
-    let Some(paths) = std::env::var_os("PATH") else {
-        return false;
-    };
-    std::env::split_paths(&paths).any(|dir| dir.join(command).is_file())
-}
-
-enum Slot {
-    Ready(Arc<LspClient>),
-    Failed,
-}
-
-pub struct LspPool {
-    root: PathBuf,
-    servers: Vec<ServerConfig>,
-    /// One slot per server name; absent until first spawn attempt.
-    clients: tokio::sync::Mutex<HashMap<String, Slot>>,
-    /// Open documents → last-sent version, so `didChange` bumps monotonically.
-    open: Mutex<HashMap<PathBuf, i32>>,
-}
-
-impl LspPool {
-    /// Builds a pool: available built-ins plus any `config` servers (which override built-ins
-    /// by name; an empty command disables a built-in).
-    pub fn new(root: PathBuf, config: Vec<ServerConfig>) -> Self {
-        let mut by_name: HashMap<String, ServerConfig> = HashMap::new();
-        for server in builtin_servers() {
-            if binary_exists(&server.command) {
-                by_name.insert(server.name.clone(), server);
-            }
-        }
-        for server in config {
-            if server.command.is_empty() {
-                by_name.remove(&server.name);
-            } else {
-                by_name.insert(server.name.clone(), server);
-            }
-        }
-        Self {
-            root,
-            servers: by_name.into_values().collect(),
-            clients: tokio::sync::Mutex::new(HashMap::new()),
-            open: Mutex::new(HashMap::new()),
-        }
-    }
-
-    fn server_for(&self, path: &Path) -> Option<&ServerConfig> {
-        let ext = path.extension().and_then(|e| e.to_str())?;
-        self.servers
-            .iter()
-            .find(|s| s.extensions.iter().any(|e| e == ext))
-    }
-
-    /// Gets or lazily spawns the client for `server`. Caches a failure so we don't respawn a
-    /// broken server on every edit.
-    async fn client_for(&self, server: &ServerConfig) -> Option<Arc<LspClient>> {
-        let mut clients = self.clients.lock().await;
-        match clients.get(&server.name) {
-            Some(Slot::Ready(c)) => return Some(c.clone()),
-            Some(Slot::Failed) => return None,
-            None => {}
-        }
-        match LspClient::spawn(&server.command, &server.args, &self.root).await {
-            Ok(client) => {
-                let client = Arc::new(client);
-                clients.insert(server.name.clone(), Slot::Ready(client.clone()));
-                Some(client)
-            }
-            Err(e) => {
-                tracing::warn!(server = %server.name, error = %e, "LSP server failed to start");
-                clients.insert(server.name.clone(), Slot::Failed);
-                None
-            }
-        }
-    }
-}
-
-#[async_trait]
-impl DiagnosticsSource for LspPool {
-    async fn touch(&self, path: &Path) {
-        let Some(server) = self.server_for(path).cloned() else {
-            return;
-        };
-        let Ok(text) = tokio::fs::read_to_string(path).await else {
-            return;
-        };
-        let Some(client) = self.client_for(&server).await else {
-            return;
-        };
-        let ext = path.extension().and_then(|e| e.to_str()).unwrap_or_default();
-        let language_id = language_id_for_ext(ext);
-
-        let existing_version = {
-            let mut open = self.open.lock().unwrap();
-            match open.get_mut(path) {
-                Some(version) => {
-                    *version += 1;
-                    Some(*version)
-                }
-                None => {
-                    open.insert(path.to_path_buf(), 1);
-                    None
-                }
-            }
-        };
-
-        // Fresh diagnostics only reflect the current contents — drop any stale set first.
-        client.clear(path);
-        match existing_version {
-            None => client.did_open(path, language_id, 1, &text),
-            Some(version) => client.did_change(path, version, &text),
-        }
-    }
-
-    async fn diagnostics(&self, path: &Path, wait: Duration) -> Vec<Diagnostic> {
-        let Some(server) = self.server_for(path).cloned() else {
-            return Vec::new();
-        };
-        let Some(client) = self.client_for(&server).await else {
-            return Vec::new();
-        };
-        client.wait_diagnostics(path, wait).await
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn language_ids_map_common_extensions() {
-        assert_eq!(language_id_for_ext("rs"), "rust");
-        assert_eq!(language_id_for_ext("tsx"), "typescriptreact");
-        assert_eq!(language_id_for_ext("unknown"), "unknown");
-    }
-
-    #[test]
-    fn config_server_overrides_builtin_by_name() {
-        let pool = LspPool::new(
-            std::env::temp_dir(),
-            vec![ServerConfig {
-                name: "rust".into(),
-                command: "my-custom-ra".into(),
-                args: vec!["--flag".into()],
-                extensions: vec!["rs".into()],
-            }],
-        );
-        let server = pool.server_for(Path::new("/x/a.rs")).unwrap();
-        assert_eq!(server.command, "my-custom-ra");
-    }
-
-    #[test]
-    fn no_server_for_unknown_extension() {
-        let pool = LspPool::new(std::env::temp_dir(), vec![]);
-        assert!(pool.server_for(Path::new("/x/a.zzz")).is_none());
-    }
-
-    #[test]
-    fn binary_exists_finds_a_known_tool() {
-        assert!(binary_exists("sh"));
-        assert!(!binary_exists("definitely-not-a-real-binary-xyz"));
-    }
-}

crates/harness-lsp/tests/rust_analyzer.rs

@@ -1,34 +0,0 @@
-//! End-to-end LSP test against a real `rust-analyzer`. Ignored by default (requires the binary
-//! on PATH and is slow — RA indexes the project). Run with:
-//!   cargo test -p harness-lsp --test rust_analyzer -- --ignored --nocapture
-
-use std::time::Duration;
-
-use harness_core::lsp::{DiagnosticsSource, Severity};
-use harness_lsp::LspPool;
-
-#[tokio::test]
-#[ignore = "requires rust-analyzer on PATH; slow"]
-async fn rust_analyzer_reports_a_type_error() {
-    // Minimal cargo project with a deliberate type error.
-    let dir = tempfile::tempdir().unwrap();
-    std::fs::write(
-        dir.path().join("Cargo.toml"),
-        "[package]\nname = \"probe\"\nversion = \"0.1.0\"\nedition = \"2021\"\n",
-    )
-    .unwrap();
-    std::fs::create_dir_all(dir.path().join("src")).unwrap();
-    let main_rs = dir.path().join("src/main.rs");
-    std::fs::write(&main_rs, "fn main() {\n    let x: i32 = \"not an integer\";\n    let _ = x;\n}\n").unwrap();
-
-    let pool = LspPool::new(dir.path().to_path_buf(), vec![]);
-    pool.touch(&main_rs).await;
-    // Generous wait: rust-analyzer must index the workspace before it reports anything.
-    let diags = pool.diagnostics(&main_rs, Duration::from_secs(60)).await;
-
-    println!("diagnostics: {diags:#?}");
-    assert!(
-        diags.iter().any(|d| d.severity == Severity::Error),
-        "expected at least one error diagnostic, got: {diags:?}"
-    );
-}

crates/harness-providers/src/openai.rs

@@ -8,8 +8,6 @@ use tokio_util::sync::CancellationToken;
 use crate::codec::{openai_chat, openai_responses};
 
 const DEFAULT_BASE_URL: &str = "https://api.openai.com/v1";
-/// OpenCode Zen's OpenAI-compatible gateway (chat-completions only).
-const OPENCODE_BASE_URL: &str = "https://opencode.ai/zen/v1";
 
 /// Which OpenAI wire format to speak for a given model.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -35,57 +33,28 @@ fn flavor_for(model: &str) -> ApiFlavor {
 }
 
 pub struct OpenAiProvider {
-    id: String,
     api_key: String,
     base_url: String,
-    /// When set, always speak chat-completions regardless of model name — required for
-    /// OpenAI-compatible gateways (e.g. OpenCode Zen) that don't implement `/responses`.
-    chat_only: bool,
     client: reqwest::Client,
 }
 
 impl OpenAiProvider {
     pub fn new(api_key: impl Into<String>) -> Self {
         Self {
-            id: "openai".to_string(),
             api_key: api_key.into(),
             base_url: DEFAULT_BASE_URL.to_string(),
-            chat_only: false,
             client: reqwest::Client::new(),
         }
     }
 
     pub fn with_base_url(api_key: impl Into<String>, base_url: impl Into<String>) -> Self {
         Self {
-            id: "openai".to_string(),
             api_key: api_key.into(),
             base_url: base_url.into(),
-            chat_only: false,
             client: reqwest::Client::new(),
         }
     }
 
-    /// An OpenCode Zen provider: id `opencode`, chat-completions only, defaulting to Zen's
-    /// gateway. Pass `base_url = None` to use the default endpoint.
-    pub fn opencode(api_key: impl Into<String>, base_url: Option<String>) -> Self {
-        Self {
-            id: "opencode".to_string(),
-            api_key: api_key.into(),
-            base_url: base_url.unwrap_or_else(|| OPENCODE_BASE_URL.to_string()),
-            chat_only: true,
-            client: reqwest::Client::new(),
-        }
-    }
-
-    /// The wire format for `model`, honoring `chat_only`.
-    fn flavor(&self, model: &str) -> ApiFlavor {
-        if self.chat_only {
-            ApiFlavor::Chat
-        } else {
-            flavor_for(model)
-        }
-    }
-
     fn classify_error(
         status: reqwest::StatusCode,
         body: String,
@@ -108,7 +77,7 @@ impl OpenAiProvider {
 #[async_trait]
 impl Provider for OpenAiProvider {
     fn id(&self) -> &str {
-        &self.id
+        "openai"
     }
 
     async fn list_models(&self) -> Result<Vec<ModelInfo>, ProviderError> {
@@ -121,7 +90,7 @@ impl Provider for OpenAiProvider {
         req: LlmRequest,
         cancel: CancellationToken,
     ) -> Result<LlmEventStream, ProviderError> {
-        let (path, body) = match self.flavor(&req.model) {
+        let (path, body) = match flavor_for(&req.model) {
             ApiFlavor::Responses => ("/responses", openai_responses::build_request(&req)),
             ApiFlavor::Chat => ("/chat/completions", openai_chat::build_request(&req)),
         };
@@ -151,7 +120,7 @@ impl Provider for OpenAiProvider {
             return Err(Self::classify_error(status, body, retry_after));
         }
 
-        Ok(match self.flavor(&req.model) {
+        Ok(match flavor_for(&req.model) {
             ApiFlavor::Responses => openai_responses::decode(response.bytes_stream()),
             ApiFlavor::Chat => openai_chat::decode(response.bytes_stream()),
         })
@@ -182,22 +151,6 @@ mod tests {
         assert_eq!(OpenAiProvider::new("k").id(), "openai");
     }
 
-    #[test]
-    fn opencode_provider_is_chat_only_and_ids_as_opencode() {
-        let p = OpenAiProvider::opencode("k", None);
-        assert_eq!(p.id(), "opencode");
-        assert_eq!(p.base_url, OPENCODE_BASE_URL);
-        // Even a gpt-*/o* model must route to chat completions on a chat-only gateway.
-        assert_eq!(p.flavor("gpt-5.5"), ApiFlavor::Chat);
-        assert_eq!(p.flavor("claude-sonnet-5"), ApiFlavor::Chat);
-    }
-
-    #[test]
-    fn opencode_honors_custom_base_url() {
-        let p = OpenAiProvider::opencode("k", Some("https://example.test/v1".into()));
-        assert_eq!(p.base_url, "https://example.test/v1");
-    }
-
     #[test]
     fn classifies_context_overflow_from_400_body() {
         assert!(matches!(

crates/harness-tools/src/bash.rs

@@ -149,9 +149,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tools/src/diagnostics.rs

@@ -1,68 +0,0 @@
-//! Shared LSP-diagnostics reporting for the edit/write tools. After a file is written we ask
-//! the (optional) diagnostics source to re-analyze it and append any error-severity items to
-//! the tool output so the model sees mistakes it just introduced. Best-effort: no source, a
-//! slow server, or a timeout all just mean "no diagnostics" — never a tool failure.
-
-use std::path::Path;
-use std::time::Duration;
-
-use harness_core::lsp::Severity;
-use harness_core::tool::{ToolCtx, ToolOutput};
-
-/// docs/09-integrations.md: wait up to 1.5s for the server to (re)publish after the change.
-const DIAGNOSTICS_WAIT: Duration = Duration::from_millis(1500);
-
-/// Touches `path` in the language server and appends error-severity diagnostics to `output`
-/// (both as a human-readable block in the text and the full set in metadata under `diagnostics`).
-pub async fn append_diagnostics(ctx: &ToolCtx, path: &Path, display_name: &str, output: &mut ToolOutput) {
-    let Some(source) = &ctx.diagnostics else {
-        return;
-    };
-    source.touch(path).await;
-    let diagnostics = source.diagnostics(path, DIAGNOSTICS_WAIT).await;
-    if diagnostics.is_empty() {
-        return;
-    }
-
-    let errors: Vec<_> = diagnostics
-        .iter()
-        .filter(|d| d.severity == Severity::Error)
-        .collect();
-    if !errors.is_empty() {
-        output
-            .output
-            .push_str("\n\nLSP errors detected in this file, please fix:");
-        for diag in &errors {
-            output.output.push('\n');
-            output.output.push_str(&diag.display_line(display_name));
-        }
-    }
-
-    // Full set (all severities) into metadata for the TUI.
-    let items: Vec<serde_json::Value> = diagnostics
-        .iter()
-        .map(|d| {
-            serde_json::json!({
-                "line": d.line,
-                "character": d.character,
-                "severity": severity_str(d.severity),
-                "message": d.message,
-                "source": d.source,
-            })
-        })
-        .collect();
-    if let serde_json::Value::Object(map) = &mut output.metadata {
-        map.insert("diagnostics".into(), serde_json::Value::Array(items));
-    } else {
-        output.metadata = serde_json::json!({ "diagnostics": items });
-    }
-}
-
-fn severity_str(severity: Severity) -> &'static str {
-    match severity {
-        Severity::Error => "error",
-        Severity::Warning => "warning",
-        Severity::Info => "info",
-        Severity::Hint => "hint",
-    }
-}

crates/harness-tools/src/edit/mod.rs

@@ -196,9 +196,8 @@ impl Tool for EditTool {
             .map_err(|e| ToolError::Other(format!("{}: {e}", path.display())))?;
 
         let (added, removed) = diff_stats(&content_old, &content_new);
-        let mut output = ToolOutput::new(pattern.clone(), "Edit applied successfully.".to_string());
+        let mut output = ToolOutput::new(pattern, "Edit applied successfully.".to_string());
         output.metadata = serde_json::json!({"diff": diff, "added": added, "removed": removed});
-        crate::diagnostics::append_diagnostics(&ctx, &path, &pattern, &mut output).await;
         Ok(output)
     }
 }
@@ -233,9 +232,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tools/src/glob.rs

@@ -130,9 +130,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tools/src/grep.rs

@@ -159,9 +159,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tools/src/lib.rs

@@ -1,11 +1,9 @@
 mod bash;
-mod diagnostics;
 mod edit;
 mod glob;
 mod grep;
 mod paths;
 mod read;
-mod task;
 mod write;
 
 pub use bash::BashTool;
@@ -13,7 +11,6 @@ pub use edit::EditTool;
 pub use glob::GlobTool;
 pub use grep::GrepTool;
 pub use read::ReadTool;
-pub use task::TaskTool;
 pub use write::WriteTool;
 
 use std::sync::Arc;
@@ -29,10 +26,3 @@ pub fn register_builtins(registry: &mut ToolRegistry) {
     registry.register(Arc::new(GlobTool));
     registry.register(Arc::new(GrepTool));
 }
-
-/// Registers the multiagent `task` tool (M4). Kept separate from [`register_builtins`] so
-/// non-orchestrating contexts can omit delegation; the tool no-ops with an error if the
-/// session has no spawner wired in.
-pub fn register_task_tool(registry: &mut ToolRegistry) {
-    registry.register(Arc::new(TaskTool));
-}

crates/harness-tools/src/read.rs

@@ -102,13 +102,6 @@ impl Tool for ReadTool {
                 "(empty file or offset past end)".to_string(),
             ));
         }
-
-        // In a subagent session, advertise this read on the job board.
-        if let Some(reporter) = &ctx.context_reporter {
-            let reported = paths::relative_pattern(&ctx.cwd, &path);
-            reporter.report_file(reported, numbered.len() as u32).await;
-        }
-
         Ok(ToolOutput::new(
             params.file_path.clone(),
             numbered.join("\n"),
@@ -146,9 +139,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tools/src/task.rs

@@ -1,140 +0,0 @@
-//! The `task` tool: delegate work to a specialist subagent, foreground or background.
-//!
-//! This tool is deliberately thin — it validates input, gates on a `task/<agent>` permission,
-//! and hands off to the engine's `SubagentSpawner` (owned by the composition root), which
-//! resolves the agent, enforces the depth limit, applies permission intersection, and runs
-//! the child session. See `docs/04-multiagent.md`.
-
-use async_trait::async_trait;
-use serde::Deserialize;
-use serde_json::json;
-
-use harness_core::tool::{
-    invalid_input, SpawnError, SpawnRequest, Tool, ToolCtx, ToolError, ToolOutput,
-};
-
-#[derive(Debug, Deserialize)]
-struct TaskInput {
-    /// Short human-facing label for the subtask (shown on the job board).
-    description: String,
-    /// The full instruction handed to the subagent.
-    prompt: String,
-    /// Which specialist to run (must be a subagent-capable agent).
-    subagent_type: String,
-    /// Alias or task id of a completed job to continue instead of starting fresh.
-    #[serde(default)]
-    task_id: Option<String>,
-    /// Run in the background and return immediately (tracked on the job board).
-    #[serde(default)]
-    background: bool,
-}
-
-pub struct TaskTool;
-
-#[async_trait]
-impl Tool for TaskTool {
-    fn name(&self) -> &str {
-        "task"
-    }
-
-    fn description(&self) -> &str {
-        "Delegate a self-contained unit of work to a specialist subagent. Set `background: \
-         true` to launch it without blocking (track progress on the job board); reuse a \
-         completed subagent by passing its `task_id`/alias to continue the same session."
-    }
-
-    fn parameters(&self) -> serde_json::Value {
-        json!({
-            "type": "object",
-            "properties": {
-                "description": { "type": "string", "description": "Short label for the subtask." },
-                "prompt": { "type": "string", "description": "Full instruction for the subagent." },
-                "subagent_type": { "type": "string", "description": "Specialist to run." },
-                "task_id": { "type": "string", "description": "Alias/id of a completed job to reuse." },
-                "background": { "type": "boolean", "description": "Launch without blocking." }
-            },
-            "required": ["description", "prompt", "subagent_type"]
-        })
-    }
-
-    async fn execute(
-        &self,
-        input: serde_json::Value,
-        ctx: ToolCtx,
-    ) -> Result<ToolOutput, ToolError> {
-        let args: TaskInput = serde_json::from_value(input).map_err(|e| invalid_input(self, e))?;
-
-        let Some(spawner) = ctx.spawner.clone() else {
-            return Err(ToolError::Other(
-                "subagent delegation is not available in this session".into(),
-            ));
-        };
-
-        // Gate on task/<agent>. `Always` grants blanket delegation to this specialist.
-        ctx.ask
-            .ask(
-                "task",
-                &args.subagent_type,
-                &args.subagent_type,
-                json!({
-                    "agent": args.subagent_type,
-                    "description": args.description,
-                    "background": args.background,
-                }),
-            )
-            .await?;
-
-        let req = SpawnRequest {
-            parent_session_id: ctx.session_id.clone(),
-            parent_message_id: ctx.message_id.clone(),
-            agent: args.subagent_type.clone(),
-            description: args.description.clone(),
-            prompt: args.prompt,
-            reuse_task_id: args.task_id,
-            background: args.background,
-            cancel: ctx.cancel.clone(),
-        };
-
-        let outcome = spawner.spawn(req).await.map_err(map_spawn_error)?;
-
-        if outcome.background {
-            let alias = outcome.alias.unwrap_or_default();
-            Ok(ToolOutput {
-                title: format!("launched {} ({alias})", args.subagent_type),
-                output: format!(
-                    "Launched background task {alias} ({}). Check the job board; do not poll — \
-                     wait for completion.",
-                    outcome.child_session_id
-                ),
-                metadata: json!({
-                    "child_session": outcome.child_session_id,
-                    "agent": args.subagent_type,
-                    "alias": alias,
-                    "background": true,
-                }),
-            })
-        } else {
-            let text = outcome.final_text.unwrap_or_default();
-            Ok(ToolOutput {
-                title: format!("{} — {}", args.subagent_type, args.description),
-                output: text,
-                metadata: json!({
-                    "child_session": outcome.child_session_id,
-                    "agent": args.subagent_type,
-                    "background": false,
-                }),
-            })
-        }
-    }
-}
-
-fn map_spawn_error(err: SpawnError) -> ToolError {
-    match err {
-        // Depth/agent problems are the model's to fix — surface as tool errors it can read
-        // and act on, not hard failures.
-        SpawnError::DepthExceeded => ToolError::Other(err.to_string()),
-        SpawnError::InvalidAgent(_) => ToolError::Invalid(err.to_string()),
-        SpawnError::ReuseNotFound(_) => ToolError::Invalid(err.to_string()),
-        SpawnError::Other(msg) => ToolError::Other(msg),
-    }
-}

crates/harness-tools/src/write.rs

@@ -80,7 +80,6 @@ impl Tool for WriteTool {
             format!("wrote {} bytes", params.content.len()),
         );
         output.metadata = serde_json::json!({"diff": diff, "added": added, "removed": removed});
-        crate::diagnostics::append_diagnostics(&ctx, &path, &params.file_path, &mut output).await;
         Ok(output)
     }
 }
@@ -115,9 +114,6 @@ mod tests {
                 CancellationToken::new(),
             ),
             metadata,
-            spawner: None,
-            context_reporter: None,
-            diagnostics: None,
         }
     }
 

crates/harness-tui/src/input.rs

@@ -23,10 +23,6 @@ pub enum InputAction {
     SessionPickerUp,
     SessionPickerDown,
     SessionPickerSelect,
-    OpenJobs,
-    JobsUp,
-    JobsDown,
-    JobsDrillIn,
 }
 
 /// Translate a crossterm event into an action and/or mutate `state` directly.
@@ -53,21 +49,10 @@ fn handle_key(key: KeyEvent, state: &mut AppState) -> InputAction {
     match &state.modal {
         ModalState::Permission { .. } => handle_permission_key(key, state),
         ModalState::SessionPicker { .. } => handle_session_picker_key(key, state),
-        ModalState::JobsPane { .. } => handle_jobs_pane_key(key, state),
         ModalState::None => handle_normal_key(key, state),
     }
 }
 
-fn handle_jobs_pane_key(key: KeyEvent, _state: &mut AppState) -> InputAction {
-    match key.code {
-        KeyCode::Up => InputAction::JobsUp,
-        KeyCode::Down => InputAction::JobsDown,
-        KeyCode::Enter => InputAction::JobsDrillIn,
-        KeyCode::Esc => InputAction::CloseModal,
-        _ => InputAction::None,
-    }
-}
-
 fn handle_permission_key(key: KeyEvent, _state: &mut AppState) -> InputAction {
     match key.code {
         KeyCode::Char('y') | KeyCode::Char('Y') => {
@@ -134,7 +119,6 @@ fn handle_normal_key(key: KeyEvent, state: &mut AppState) -> InputAction {
             }
         }
         KeyCode::Char('s') if ctrl => InputAction::LoadSessions,
-        KeyCode::Char('j') if ctrl => InputAction::OpenJobs,
         KeyCode::Up => {
             let (row, _) = state.input.cursor();
             if row == 0 {
@@ -174,7 +158,6 @@ fn parse_slash_command(text: &str) -> Option<InputAction> {
         "/model" if !rest.is_empty() => Some(InputAction::SetModel(rest)),
         "/agent" if !rest.is_empty() => Some(InputAction::SetAgent(rest)),
         "/sessions" => Some(InputAction::LoadSessions),
-        "/jobs" => Some(InputAction::OpenJobs),
         "/quit" => Some(InputAction::Quit),
         _ => None,
     }
@@ -252,45 +235,6 @@ pub async fn apply_action(action: InputAction, state: &mut AppState, engine: &En
                 }
             }
         }
-        InputAction::OpenJobs => {
-            if let Some(session_id) = state.session_id.clone() {
-                match engine.jobs(session_id).await {
-                    Ok(jobs) => {
-                        state.set_jobs(jobs);
-                        state.open_jobs_pane();
-                    }
-                    Err(e) => tracing::error!(error = %e, "failed to load jobs"),
-                }
-            }
-        }
-        InputAction::JobsUp => {
-            if let ModalState::JobsPane { selected } = &mut state.modal {
-                *selected = selected.saturating_sub(1);
-            }
-            state.dirty = true;
-        }
-        InputAction::JobsDown => {
-            let job_count = state.jobs.len();
-            if let ModalState::JobsPane { selected } = &mut state.modal {
-                if *selected + 1 < job_count {
-                    *selected += 1;
-                }
-            }
-            state.dirty = true;
-        }
-        InputAction::JobsDrillIn => {
-            if let Some(child) = state.selected_job_child() {
-                match engine.get_session(child).await {
-                    Ok(Some(session)) => {
-                        if let Err(e) = modal::select_session(state, engine, session).await {
-                            tracing::error!(error = %e, "failed to open subtask session");
-                        }
-                    }
-                    Ok(None) => tracing::warn!("subtask session no longer exists"),
-                    Err(e) => tracing::error!(error = %e, "failed to load subtask session"),
-                }
-            }
-        }
         InputAction::None => {}
     }
 }

crates/harness-tui/src/modal.rs

@@ -26,17 +26,13 @@ pub async fn select_session(
     session: Session,
 ) -> Result<(), harness_app::AppError> {
     let session_id = session.id.clone();
-    let messages = engine.session_messages(session_id.clone()).await?;
+    let messages = engine.session_messages(session_id).await?;
     let mut all_parts = Vec::new();
     for message in &messages {
         let parts = engine.message_parts(message.id.clone()).await?;
         all_parts.extend(parts);
     }
     state.set_session(session, messages, all_parts);
-    // Surface any subtasks this session spawned (drill-in and session-switch both land here).
-    if let Ok(jobs) = engine.jobs(session_id).await {
-        state.set_jobs(jobs);
-    }
     state.modal = ModalState::None;
     Ok(())
 }

crates/harness-tui/src/render.rs

@@ -33,9 +33,6 @@ pub fn render(frame: &mut Frame, state: &mut AppState) {
         ModalState::SessionPicker { sessions, selected } => {
             render_session_picker(frame, sessions, *selected, area);
         }
-        ModalState::JobsPane { selected } => {
-            render_jobs_pane(frame, &state.jobs, *selected, area);
-        }
         ModalState::None => {}
     }
 }
@@ -172,7 +169,7 @@ fn render_status(frame: &mut Frame, state: &AppState, area: Rect) {
     let hints = if state.ctrl_c_pressed {
         "Press Ctrl+C again to quit"
     } else {
-        "Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C: quit"
+        "Ctrl+S: sessions | Esc: abort | Ctrl+C: quit"
     };
     let usage = format!(
         "{} · ${:.4}",
@@ -245,86 +242,6 @@ fn render_session_picker(
     frame.render_widget(paragraph, popup);
 }
 
-fn render_jobs_pane(
-    frame: &mut Frame,
-    jobs: &[harness_core::engine::JobRecord],
-    selected: usize,
-    area: Rect,
-) {
-    let popup = centered_rect(70, 70, area);
-    frame.render_widget(Clear, popup);
-
-    let mut text: Vec<Line<'static>> =
-        vec![Line::from("Background jobs").style(Style::new().add_modifier(Modifier::BOLD))];
-
-    if jobs.is_empty() {
-        text.push(Line::default());
-        text.push(Line::from("No subtasks spawned yet.").style(Style::new().fg(Color::DarkGray)));
-    } else {
-        for (i, job) in jobs.iter().enumerate() {
-            let marker = if i == selected { "> " } else { "  " };
-            let (icon, color) = job_state_style(job.state);
-            let header = format!(
-                "{marker}{icon} {} · {} · {}",
-                job.alias,
-                job.agent,
-                job_state_label(job.state),
-            );
-            let style = if i == selected {
-                Style::new().bg(Color::Blue).fg(Color::White)
-            } else {
-                Style::new().fg(color)
-            };
-            text.push(Line::from(Span::styled(header, style)));
-            if let Some(objective) = &job.objective {
-                text.push(
-                    Line::from(format!("    {objective}")).style(Style::new().fg(Color::Gray)),
-                );
-            }
-            if !job.context_files.is_empty() {
-                let files: Vec<&str> = job
-                    .context_files
-                    .iter()
-                    .take(8)
-                    .map(|f| f.path.as_str())
-                    .collect();
-                text.push(
-                    Line::from(format!("    read: {}", files.join(", ")))
-                        .style(Style::new().fg(Color::DarkGray)),
-                );
-            }
-        }
-        text.push(Line::default());
-        text.push(
-            Line::from("Enter: open subtask · Esc: close").style(Style::new().fg(Color::DarkGray)),
-        );
-    }
-
-    let block = Block::default().borders(Borders::ALL).title(" jobs ");
-    let paragraph = Paragraph::new(text).block(block).wrap(Wrap { trim: false });
-    frame.render_widget(paragraph, popup);
-}
-
-fn job_state_label(state: harness_core::engine::JobState) -> &'static str {
-    use harness_core::engine::JobState;
-    match state {
-        JobState::Running => "running",
-        JobState::Completed => "completed",
-        JobState::Error => "error",
-        JobState::Cancelled => "cancelled",
-    }
-}
-
-fn job_state_style(state: harness_core::engine::JobState) -> (&'static str, Color) {
-    use harness_core::engine::JobState;
-    match state {
-        JobState::Running => ("⚙", Color::Yellow),
-        JobState::Completed => ("✓", Color::Green),
-        JobState::Error => ("✗", Color::Red),
-        JobState::Cancelled => ("∅", Color::DarkGray),
-    }
-}
-
 fn centered_rect(percent_x: u16, percent_y: u16, r: Rect) -> Rect {
     let popup_layout = Layout::default()
         .direction(Direction::Vertical)
@@ -570,59 +487,6 @@ mod tests {
         insta::assert_snapshot!(buffer_to_string(terminal.backend()));
     }
 
-    #[test]
-    fn snapshot_jobs_pane() {
-        use harness_core::engine::{ContextFile, JobRecord, JobState};
-
-        let backend = TestBackend::new(80, 24);
-        let mut terminal = Terminal::new(backend).unwrap();
-        let mut state = AppState::new(
-            "anthropic/claude-sonnet-4-5".to_string(),
-            "orchestrator".to_string(),
-        );
-        state.session_id = Some(SessionId("ses_test_001".to_string()));
-        state.jobs = vec![
-            JobRecord {
-                task_id: "t1".to_string(),
-                alias: "exp-1".to_string(),
-                parent_session: SessionId("ses_test_001".to_string()),
-                child_session: SessionId("ses_child_001".to_string()),
-                agent: "explorer".to_string(),
-                description: "map auth".to_string(),
-                objective: Some("map the auth flow".to_string()),
-                state: JobState::Completed,
-                reconciled: true,
-                result_summary: Some("done".to_string()),
-                context_files: vec![ContextFile {
-                    path: "src/auth.rs".to_string(),
-                    lines: 42,
-                }],
-                launched_at: 1,
-                updated_at: 2,
-                last_used_at: 2,
-            },
-            JobRecord {
-                task_id: "t2".to_string(),
-                alias: "fix-1".to_string(),
-                parent_session: SessionId("ses_test_001".to_string()),
-                child_session: SessionId("ses_child_002".to_string()),
-                agent: "fixer".to_string(),
-                description: "patch bug".to_string(),
-                objective: Some("fix the null deref".to_string()),
-                state: JobState::Running,
-                reconciled: false,
-                result_summary: None,
-                context_files: Vec::new(),
-                launched_at: 3,
-                updated_at: 3,
-                last_used_at: 3,
-            },
-        ];
-        state.modal = ModalState::JobsPane { selected: 1 };
-        terminal.draw(|frame| render(frame, &mut state)).unwrap();
-        insta::assert_snapshot!(buffer_to_string(terminal.backend()));
-    }
-
     #[test]
     fn render_empty_state_produces_frame() {
         let backend = TestBackend::new(80, 24);

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_empty_session.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 381
+assertion_line: 300
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_jobs_pane.snap

@@ -1,29 +0,0 @@
----
-source: crates/harness-tui/src/render.rs
-assertion_line: 621
-expression: buffer_to_string(terminal.backend())
----
-            new session · orchestrator · anthropic/claude-sonnet-4-5
-┌ chat ────────────────────────────────────────────────────────────────────────┐
-│                                                                              │
-│                                                                              │
-│           ┌ jobs ────────────────────────────────────────────────┐           │
-│           │Background jobs                                       │           │
-│           │  ✓ exp-1 · explorer · completed                      │           │
-│           │    map the auth flow                                 │           │
-│           │    read: src/auth.rs                                 │           │
-│           │> ⚙ fix-1 · fixer · running                           │           │
-│           │    fix the null deref                                │           │
-│           │                                                      │           │
-│           │Enter: open subtask · Esc: close                      │           │
-│           │                                                      │           │
-│           │                                                      │           │
-│           │                                                      │           │
-│           │                                                      │           │
-│           │                                                      │           │
-│           │                                                      │           │
-└───────────└──────────────────────────────────────────────────────┘───────────┘
-┌ input ───────────────────────────────────────────────────────────────────────┐
-│                                                                              │
-└──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_permission_modal.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 511
+assertion_line: 430
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_session_picker_modal.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 568
+assertion_line: 487
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_tool_card_completed.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 438
+assertion_line: 357
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_tool_card_error.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 488
+assertion_line: 407
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_tool_card_running.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 463
+assertion_line: 382
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/snapshots/harness__render__tests__snapshot_user_and_assistant_messages.snap

@@ -1,6 +1,6 @@
 ---
 source: crates/harness-tui/src/render.rs
-assertion_line: 412
+assertion_line: 331
 expression: buffer_to_string(terminal.backend())
 ---
             new session · orchestrator · anthropic/claude-sonnet-4-5
@@ -26,4 +26,4 @@ expression: buffer_to_string(terminal.backend())
 ┌ input ───────────────────────────────────────────────────────────────────────┐
 │                                                                              │
 └──────────────────────────────────────────────────────────────────────────────┘
-idle · 0 tok · $0.0000 · Ctrl+S: sessions | Ctrl+J: jobs | Esc: abort | Ctrl+C:
+idle · 0 tok · $0.0000 · Ctrl+S: sessions | Esc: abort | Ctrl+C: quit

crates/harness-tui/src/state.rs

@@ -1,5 +1,4 @@
 use harness_app::EngineHandle;
-use harness_core::engine::JobRecord;
 use harness_core::event::{AppEvent, PermissionRequest, RunOutcome};
 use harness_core::permission::PermissionReply;
 use harness_core::types::{Message, Part, PartBody, PartId, Role, Session, SessionId, ToolState};
@@ -87,10 +86,6 @@ pub enum ModalState {
         sessions: Vec<Session>,
         selected: usize,
     },
-    /// Background job board for the current session, with a cursor for drill-in.
-    JobsPane {
-        selected: usize,
-    },
 }
 
 /// All mutable UI state lives here.
@@ -114,9 +109,6 @@ pub struct AppState {
     pub session_cost: f64,
     /// Accumulated session tokens (input + output), for the status bar.
     pub session_tokens: u64,
-    /// Background jobs spawned by the current session, newest activity last. Populated on
-    /// session load and kept live via `JobUpdated` events; surfaced in the jobs pane.
-    pub jobs: Vec<JobRecord>,
 }
 
 impl AppState {
@@ -139,7 +131,6 @@ impl AppState {
             render_width: 0,
             session_cost: 0.0,
             session_tokens: 0,
-            jobs: Vec::new(),
         }
     }
 
@@ -165,8 +156,6 @@ impl AppState {
         self.session_cost = session.cost;
         self.session_tokens = session.usage.input + session.usage.output;
         self.messages.clear();
-        // Jobs are reloaded for the newly-selected session by the caller.
-        self.jobs.clear();
 
         let mut messages = messages;
         messages.sort_by_key(|m| m.created_at);
@@ -269,50 +258,14 @@ impl AppState {
                 }
                 self.dirty = true;
             }
-            AppEvent::JobUpdated { job } => {
+            AppEvent::JobUpdated { .. }
-                if let Ok(record) = serde_json::from_value::<JobRecord>(job.0) {
+            | AppEvent::AuthPrompt { .. }
-                    if self.session_id.as_ref() == Some(&record.parent_session) {
+            | AppEvent::ServerNotice { .. } => {
-                        self.upsert_job(record);
-                        self.dirty = true;
-                    }
-                }
-            }
-            AppEvent::AuthPrompt { .. } | AppEvent::ServerNotice { .. } => {
                 self.dirty = true;
             }
         }
     }
 
-    /// Replaces this session's job list (e.g. after loading a session).
-    pub fn set_jobs(&mut self, jobs: Vec<JobRecord>) {
-        self.jobs = jobs;
-        self.dirty = true;
-    }
-
-    /// Inserts or replaces a job by `task_id`, preserving list order for stable rendering.
-    fn upsert_job(&mut self, record: JobRecord) {
-        if let Some(existing) = self.jobs.iter_mut().find(|j| j.task_id == record.task_id) {
-            *existing = record;
-        } else {
-            self.jobs.push(record);
-        }
-    }
-
-    /// Opens the jobs pane (cursor at the top).
-    pub fn open_jobs_pane(&mut self) {
-        self.modal = ModalState::JobsPane { selected: 0 };
-        self.dirty = true;
-    }
-
-    /// Child session of the currently-selected job in the jobs pane, for drill-in.
-    pub fn selected_job_child(&self) -> Option<SessionId> {
-        if let ModalState::JobsPane { selected } = &self.modal {
-            self.jobs.get(*selected).map(|j| j.child_session.clone())
-        } else {
-            None
-        }
-    }
-
     pub fn scroll_up(&mut self, n: u16) {
         self.scroll_offset = self.scroll_offset.saturating_sub(n);
         self.dirty = true;