- types::ModelCost {input, output, cache_read, cache_write} (USD per 1M tokens)
with cost_of(usage); reasoning tokens are billed within output by our providers
so they are not charged separately. ModelInfo gains cost + reasoning/tool_call/
attachment capability flags (all #[serde(default)] for forward-compat).
- Engine: RunConfig.cost threads pricing into process_step; on_finish now stamps
the real dollar cost onto the StepFinish part; StepOutcome carries per-step cost.
- run_session accumulates each step's usage and cost onto the session (previously
never updated) and republishes SessionUpdated — best-effort, store errors logged
not fatal.
- Store gains a single-session getter (Session cmd + get_session).
- App passes cost: None for now (real rates land with models.dev wiring).
- Tests: ModelCost::cost_of math (+ reasoning exclusion), and the multi-step
engine test now asserts session usage/cost accumulation.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
harness-core now has everything the headless agent loop needs:
- Tool trait/ToolCtx/ToolRegistry + 30k-char head+tail output truncation
- PermissionService: async ask over a oneshot + AppEvent::PermissionAsked,
Once/Always/Reject replies, an auto-approve stub for tests/headless runs
- Config: JSONC loading, bundled/global/project-chain/env precedence,
{env:VAR} and {file:path} interpolation
- llm.rs: LlmEvent/LlmRequest/Provider trait, wire message/content types
- engine/: outer loop (run_session), inner stream processor (persists
parts/messages as events arrive, executes tool calls inline), retry
policy (retries only the pre-first-event window), doom-loop guard,
system prompt assembly
Verified end-to-end against a scripted MockProvider: text -> tool call
(read) -> final text, with messages/parts persisted in the right shape,
plus a provider-error-before-any-event case surfacing as Errored (no
partial message left behind). 49 tests passing, clippy clean.
darmanandClaude Opus 4.8