# Review by Staff Security Engineer (Round 3)

Good — tokens are read from environment variables, not hardcoded. Now I have everything I need for the review.

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## Security Review: Unified Slack-to-Queue Autonomous Pipeline

### Completeness
- [x] All functional requirements from the PRD are implemented (FR-1 through FR-21)
- [x] All tasks in the task file are marked complete
- [x] No placeholder or TODO code remains

### Quality
- [x] Code follows existing project conventions
- [x] No unnecessary dependencies added (zero new external deps)
- [x] No unrelated changes included (README and test_registry_sync changes are related)

### Safety
- [x] No secrets or credentials in committed code
- [x] No destructive database operations without safeguards
- [x] Error handling is present for failure cases

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VERDICT: approve

FINDINGS:
- [src/colonyos/slack.py]: **Strong** — Triage agent runs with `allowed_tools=[]` and a $0.05 budget cap, minimizing prompt injection blast radius. This is exactly the right design for processing untrusted Slack input.
- [src/colonyos/slack.py]: **Strong** — `is_valid_git_ref()` uses a strict character allowlist (`[a-zA-Z0-9._/-]`) and rejects `..` traversal, leading/trailing slashes, and length >255. This blocks command injection and path traversal via LLM-supplied branch names.
- [src/colonyos/slack.py]: **Strong** — Defense-in-depth: `base_branch` is validated at three independent points: (1) `extract_base_branch()` at message parse time, (2) `_parse_triage_response()` when reading LLM output, and (3) `orchestrator.run()` at the point of use before any `subprocess.run` call. Any single layer failing still leaves two others.
- [src/colonyos/slack.py]: **Strong** — Message text is sanitized via `sanitize_slack_content()` before being passed to the triage prompt, defending against prompt injection through crafted Slack messages.
- [src/colonyos/orchestrator.py]: **Good** — `subprocess.run` calls for git operations use `capture_output=True` and `timeout=30`, preventing hung processes. Branch names passed to subprocess are pre-validated against the allowlist, preventing shell injection.
- [src/colonyos/orchestrator.py]: **Good** — Original branch is restored in a `finally` block after base-branch checkout, ensuring the long-running watch process returns to a known state even if the pipeline crashes.
- [src/colonyos/config.py]: **Good** — `daily_budget_usd` defaults to `None` (no default spend limit that could be silently dangerous). Positive-value validation on all numeric config fields prevents misconfiguration.
- [src/colonyos/cli.py]: **Minor concern** — `slack_client_ref: list[object] = []` is a mutable shared reference between the event handler and executor threads. While functionally correct (the executor defers if empty), this is a fragile pattern. A `threading.Event` or explicit initialization would be more robust.
- [src/colonyos/cli.py]: **Minor concern** — Queue state persistence uses JSON files with no file-level locking beyond the in-process `state_lock`. If two `colonyos watch` processes start concurrently against the same repo, they could corrupt each other's queue state. This is an existing architectural limitation, not introduced by this PR, but becomes more consequential now that the queue is the primary execution path.
- [src/colonyos/cli.py]: **Observation** — The `unpause` command reads watch state files by globbing `watch_state_*.json` and parsing them directly. This is safe because these files are generated by the system itself, but it does mean a crafted JSON file placed in the runs directory could cause unexpected behavior. Low risk given the threat model.

SYNTHESIS:
From a supply chain security and least-privilege perspective, this implementation is well-designed. The single most important security decision — making the triage agent a zero-tool, single-turn LLM call with a $0.05 budget — is correctly implemented and prevents the primary attack vector (a crafted Slack message causing the agent to exfiltrate secrets or run arbitrary code). The defense-in-depth on branch name validation (three independent validation points, strict character allowlist, `..` and shell metacharacter rejection) is thorough and well-tested. Budget controls (daily caps, per-run caps, rate limits, circuit breaker with auto-recovery) provide appropriate guardrails for always-on operation. The existing content sanitization is reused for the triage prompt. No secrets are hardcoded; Slack tokens come from environment variables. The only minor concerns are the fragile client-reference sharing pattern between threads and the lack of file-level locking on queue state (pre-existing). Neither is blocking. The test coverage for security-relevant paths (injection attempts, invalid refs, boundary conditions) is comprehensive. This is ready to merge.