Articles

Notes from building bough: what is in the files coding agents leave behind, and what reading a few hundred thousand lines of them shows.

• What is actually in a Codex CLI rollout file

  OpenAI Codex CLI records every session as a JSONL file under ~/.codex/sessions and, like Claude Code, does not document what goes in it. These are notes from reading my own and from fixing the places where bough had it wrong.

• What is actually in a Claude Code transcript

  Claude Code writes a JSONL file for every session, under ~/.claude/projects, and nobody at Anthropic has documented what is in it. These are notes from reading 275 MB of my own: 28 transcripts across 6 project directories, 76,801 lines, nothing unparseable.