Submatter/docs/worker.md

Worker (apps/worker)

Minimal first-party agent runtime for convoy automation. Consumes orchestrator jobs from Redis, resolves models via the workspace registry, runs a tool loop against a git worktree, and records claim_task / complete_task + convoy_events.role_complete.

Run locally

# Dry-run (no Redis consumer — exits after banner)
WORKER_DRY_RUN=1 pnpm --filter @tasks/worker dev

# Live consumer (requires REDIS_URL + DATABASE_URL)
pnpm --filter @tasks/worker dev

Pair with the orchestrator:

ORCHESTRATOR_DRY_RUN=0 REDIS_URL=... pnpm --filter @tasks/orchestrator dev
WORKER_DRY_RUN=0 REDIS_URL=... pnpm --filter @tasks/worker dev

Architecture

• Queue — BLPOP on echodo:orchestrator:jobs (same key as apps/orchestrator)
• Session — WorkerSession interface in @tasks/shared/worker; v1 implementation uses Vercel AI SDK generateText + tools
• Tools — read_file, write_file, grep (ripgrep), run_command (allowlist per harness: code harness pnpm lint, pnpm type-check, pnpm test, git status, git diff; doc harness [] — no run_command, only read/write/grep)
• Worktree — one git worktree per brief job under WORKER_WORKTREE_BASE when harness.needsWorktree === true (code tasks). Doc tasks (harness: doc-writer) set needsWorktree: false → worker skips ensureWorktree and runs straight against monorepoRoot (docs//plans/ writes without a branch). See apps/worker/src/harness.ts and apps/worker/src/git/worktree.ts needsWorktree param.
• Lifecycle — DB writes mirroring MCP claim_task / complete_task; role_complete convoy event on finish (includes metadata.harnessAlias)
• Harnesses — resolveHarnessForJob maps job.harnessAlias or roleId to { alias, needsWorktree, allowedCommands }; allowedCommands is threaded to runCommandTool via MinimalSession. Brief 3 will promote this to DB-backed harness_providers / role_harness_routes.

Env

Variable	Default	Purpose
DATABASE_URL	required	Convoy, backlog, model registry
REDIS_URL	optional	Job queue; missing ⇒ dry-run
WORKER_DRY_RUN	false	Skip dequeue loop
WORKER_BLPOP_TIMEOUT_S	5	Blocking pop timeout
WORKER_MAX_TOOL_STEPS	12	Max tool rounds per session
WORKER_CHECKPOINT_EVERY_N_STEPS	1	Persist a checkpoint every N tool rounds
WORKER_REPO_ROOT	monorepo root	Repo for role prompts + worktree base
WORKER_WORKTREE_BASE	/tmp/echodo-worker-worktrees	Worktree parent directory

Checkpoints & crash recovery

After each tool round (or every WORKER_CHECKPOINT_EVERY_N_STEPS rounds), the worker writes a row to worker_checkpoints (workspace-scoped): bounded tool_history, files_touched as paths + content hashes only (never API keys or full file bodies), plus branch / worktree_path.

On re-dispatch with resumeFromCheckpoint: true (orchestrator stall detector), the worker:

1. Loads the latest checkpoint for the open agent_runs row (filtered by workspace_id)
2. Reuses the saved worktree when still present — no re-clone
3. Continues the tool loop with prior steps summarized in the system prompt

Mission control convoy detail shows checkpoint count and last checkpoint time.

Provider API keys are read from env vars named in model_providers.api_key_env_var (same as web settings).