One document per harness, describing the on-disk transcript format txcript
reads and writes. These are high-level, human-readable companions to the
parsers — the code in src/harness/ and the integration tests are the
authoritative mapping; when a document and the code disagree, the code wins
and the document gets fixed.
Every document follows the same structure:
- About — what the harness is and where the knowledge in the document comes from (its provenance, see below), followed by a diagram of the format's anatomy.
- On disk — where sessions live on the computer, how files are named, and how discovery finds them.
- Dissection of a transcript — each part of the format, the name the format itself uses for it, and what txcript translates it to.
- Caveats — quirks, drift, and lossiness.
- References — citations, and a
Last verified:date.
Not all of these formats are documented by their vendors, so each document states which of three tiers its knowledge comes from:
- Official documentation — the vendor publishes a format spec; the document cites it with an access date.
- Open source — no spec, but the harness's own serialization code is public; the document cites permalinks pinned to a commit SHA.
- Reverse-engineered — closed source and undocumented; the format is described from observed sessions, and the document records the harness version and date of observation.
A dated Last verified: line closes every document. These formats drift
silently — an undated description of a reverse-engineered format is worse
than none.
| Document | Harness | Parser |
|---|---|---|
| claude-code.md | Claude Code (Anthropic) | src/harness/claude_code.rs |
| claude-chat.md | Claude Chat (Anthropic) | src/harness/claude_chat.rs |
| chatgpt.md | ChatGPT (OpenAI) | src/harness/chatgpt.rs |
| cowork.md | Cowork (Claude desktop app) | src/harness/cowork.rs |
| codex.md | Codex CLI (OpenAI) | src/harness/codex.rs |
| opencode.md | OpenCode (SST) | src/harness/opencode.rs |
| cursor.md | Cursor | src/harness/cursor.rs |
| cursor-desktop.md | Cursor desktop (IDE app) | src/harness/cursor_desktop.rs |
| amp.md | Amp (Sourcegraph) | src/harness/amp.rs |
| grok.md | Grok CLI (xAI) | src/harness/grok.rs |
| grok-bot.md | Grok Bot (desktop assistant) | src/harness/grok_bot.rs |
| fx.md | fx (Vercel) | src/harness/fx.rs |
| hermes.md | Hermes Agent | src/harness/hermes.rs |
| antigravity.md | Antigravity (Google) | src/harness/antigravity.rs |
| pi.md | pi | src/harness/pi.rs |
| campfire.md | Campfire (embeds pi) | src/harness/campfire.rs |
| simple.md | Simple (txcript's own interchange format) | src/harness/simple.rs |