# Review by Andrej Karpathy (Round 2)

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VERDICT: approve

FINDINGS:
- [src/colonyos/agent.py]: Clean 4-line change threading `resume` and `continue_conversation` into `ClaudeAgentOptions` — exactly the minimal SDK integration the PRD called for.
- [src/colonyos/cli.py — `_run_direct_agent`]: Session ID regex validation (`[A-Za-z0-9_-]+`) is good defense-in-depth. Fallback retry (fail with resume → retry fresh) correctly prevents stale sessions from blocking users.
- [src/colonyos/cli.py — REPL vs TUI]: Minor inconsistency — TUI clears `last_direct_session_id` on failure, REPL retains the last successful session ID. Not a blocker since `_run_direct_agent`'s internal fallback catches stale sessions, but worth unifying in a follow-up.
- [src/colonyos/cli.py — `/new`]: Sentinel constant `_NEW_CONVERSATION_SIGNAL` avoids fragile substring matching — clean pattern.
- [tests/]: 45 tests covering unit, integration, and E2E levels all pass. Comprehensive coverage of resume, fallback, mode-switch clearing, and `/new` reset flows.

SYNTHESIS:
This is a textbook example of using the model's native capabilities rather than fighting against them. The entire feature threads a `session_id` through three layers, stores it in a closure variable, and clears it on mode transitions — exactly the "3 lines of real logic" the PRD promised. The SDK handles transcript persistence, rehydration, and context compaction; this implementation just wires the plumbing. Design decisions are sound from an AI engineering perspective: always resume when a session exists (let the model handle irrelevant prior context gracefully), provide `/new` as the explicit escape hatch, and fall back silently on failure. The session ID validation regex treats SDK output as untrusted input — the right level of paranoia. The only nit is a minor REPL/TUI behavior inconsistency on failure, which is already backstopped by the fallback retry. Ship it.
