codex-channel-molecule is the codex-side counterpart to
hermes-channel-molecule. It long-polls the molecule platform inbox via
molecule_runtime.a2a_tools.tool_wait_for_message, runs `codex exec
--resume <session>` per inbound message, captures the assistant reply
from stdout, and routes it back through send_message_to_user (canvas
chat) or delegate_task (peer agent), then acks the inbox row.
Per chat thread (one canvas-user thread or one peer-workspace thread)
gets its own codex session_id, persisted to disk so daemon restarts
keep conversation context. Reply-routing failures skip the inbox_pop
ack so the platform's at-least-once delivery re-surfaces the row on
the next poll.
This daemon is the operator-unblock until openai/codex#17543 lands —
once codex itself accepts MCP custom notifications as Op::UserInput
through the wired-in MCP server, this daemon becomes redundant. The
README's deprecation-path section calls that out so future operators
know when to switch off.
Tests cover the dispatch loop with fake tools (8 tests asserting
exact contracts: canvas vs peer routing, session continuity,
persistence across restarts, timeout sentinel handling, at-least-once
on reply failure, exit-code surfacing, A2A multipart text). The
codex_runner tests are real-subprocess (fake codex script spawned via
asyncio.create_subprocess_exec) so the boot path matches production —
no in-process mocking of the spawn boundary.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
