--- id: agent-coordination/commit-signing-is-inconsistent-across-harnesses title: 'Commit signing is inconsistent across harnesses — Claude names itself, opencode names nothing' theme: agent-coordination status: open created: 2026-08-25 date_source: stated order: 3 --- **Every commit an agent makes should be signed with its harness name AND its chat/session id.** Raised 2026-08-25, and the owner's own audit of what actually happens today splits the work in two, because the two harnesses are missing different halves: - **Claude Code already does the harness-name half** — every commit in this repo's history carries `Co-Authored-By: Claude `. The id half is **known and already blocked**, not missed: `agent-coordination/an-agent-cannot-learn-its-own-session-id` explains why (no reliable way for a session to learn its own transcript id) and `CLAUDE.md`'s own "An agent's commit names the session that made it" section names the same precondition. Nothing new to file for Claude — this item exists for the other half. - **opencode signs nothing at all.** Not the harness name, not an id — checked 2026-08-25, no `Co-Authored-By` convention and no session-identifying trailer anywhere in `src/servers/sidecar/opencode/`. This is a DIFFERENT gap from Claude's: naming the harness has no precondition and no blocker. It could be added today, independent of the transcript-id mechanism — opencode simply has no instruction telling it to identify itself in a commit at all. So there are two pieces of work, not one, and they are not coupled: 1. **opencode: add the harness-name half now.** Whatever hands opencode its system prompt / commit conventions (the equivalent of `CLAUDE.md` for that harness — search `src/servers/sidecar/opencode/` for where its instructions are assembled) needs the same `Co-Authored-By: opencode <...>` line Claude already writes. No dependency on anything unbuilt. 2. **Both harnesses: add the id half once the precondition lands.** This is exactly `agent-coordination/an-agent-cannot-learn-its-own-session-id` — give every session its own chat id at turn time (the mechanism `commanderBlock` already proves for commanders), then both harnesses' commit trailers gain an `Officer-Session:`-style line. Do this once, generalized, rather than solving it twice per harness.