Adds an rmcp-based stdio MCP client in harness-mcp plus adapters exposing a configured server's tools as namespaced harness-tools, with an echo-server fixture and integration test, and wiring through harness-app.
Adds the DiagnosticsSource seam trait in harness-core::lsp (kept out of harness-tools so tools never link the LSP crate directly), and implements it in harness-lsp as a pool that lazily spawns one language server per file extension (rust-analyzer, typescript-language-server, gopls, pyright-langserver) only when the binary is on PATH. Adds harness-tools::diagnostics and wires diagnostics into edit/write/bash/glob/grep output.
Adds a dedicated provider entry for opencode's Zen proxy on top of the existing OpenAI-compatible codec, with its own config wiring in harness-app and harness-core::config::load.
Adds the jobs pane to the TUI with a new snapshot test, subtask drill-in navigation, and periodic reminders injected into the engine loop for long-running background jobs.
Lets subagents report context files back to the job board (surfaced from the read tool) so the parent session's next-turn context includes what a background child has been looking at.
Adds the task tool and subagent spawner in harness-tools, and wires spawning/aliasing/reuse and depth limits through harness-app and the job board, so an orchestrator session can launch and track child sessions.
Adds harness-core::engine::jobs, the JobBoard tracking foreground/background subagent jobs with persistence, plus permission-rule intersection so a spawned subagent's effective permissions are the parent's rules narrowed by its own.
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.
Adds a bundled models.dev snapshot plus harness-providers::modelsdev to resolve model metadata, and wires live cost display into the TUI's input bar and message state, updating the render snapshots accordingly.
Extends the model catalog with per-token pricing and accumulates cost per engine step, threading the running total through the store and up into harness-app so it can be surfaced in the UI.
Adds harness-providers::auth, a persisted auth.json credential store for provider tokens, laying the groundwork for Copilot's device-flow login and token refresh.
Adds both OpenAI codecs — chat completions and the newer responses API — plus the OpenAiProvider and registry wiring, so the same session can run against OpenAI in addition to Anthropic.
Builds the ratatui TUI: EngineHandle bridging the async engine to the render loop, chat viewport rendering with a markdown renderer, input handling, a permission modal wired to the real oneshot ask path, and a session picker. Adds TestBackend snapshot tests covering empty session, tool cards (running/completed/error), permission modal, session picker, and message rendering.
Adds the harness-app composition root wiring config, providers, tools, and the engine loop together, plus the harness run -p "<prompt>" debug command in harness-tui::main for driving a one-shot prompt end-to-end from the CLI.
Adds the Anthropic SSE codec (codec/anthropic.rs) translating Anthropic's event stream into LlmEvents, the AnthropicProvider, and registry wiring so the engine loop can run against the real API instead of just MockProvider.
Ports opencode's multi-strategy string-replacer chain (and its test table) into harness-tools::edit, giving the edit tool the same fuzzy-match fallback behavior opencode relies on.
Implements the first five harness-tools: read, write, bash (with timeout/output truncation), glob, and grep, plus shared path-resolution helpers. Wires them into the core tool registry and processor.
Adds the Tool trait, config loading/schema, the Provider trait plus an Llm event surface, a permission service, and the core engine loop with a doom-loop guard and retry scaffolding. The processor drives a text/tool-call/final-text turn against a Provider, laying the groundwork for the MockProvider integration test and the real Anthropic path.
Sets up the Cargo workspace (harness-core, harness-tools, harness-providers, harness-mcp, harness-lsp, harness-app, harness-tui) and the ten architecture docs under docs/. harness-core gets its foundational types (session/message/part/model ids), an in-process event bus, a table-driven permission evaluate function, and a SQLite-backed storage actor with schema and roundtrip coverage. Every crate compiles empty and a bin stub prints its version.
darman