A local-first web viewer for agent transcript .jsonl files. Drop in a transcript and jsonl.fyi renders the conversation with messages, tool calls, diffs, images, thinking blocks, timing, token usage, and model labels.
Supported formats:
- Claude Code project transcripts from
~/.claude/projects/ - OpenAI Codex rollout transcripts from
~/.codex/sessions/ - pi agent traces
Files are processed in the browser. The app stores only small recently opened files in sessionStorage so refresh/back navigation works during a session.
Install dependencies:
bun installRun the dev server:
bun devBuild for production:
bun run buildRun typechecking, linting, and formatting checks:
bun run checkThe transcript renderers are organized by source format. Claude Code, Codex, and pi have separate parse/render trees and share common UI pieces from src/transcript/.
The site is deployed as a Cloudflare Worker with Static Assets. Configuration lives in wrangler.jsonc, with SPA fallback enabled for example routes.
Production domains:
https://jsonl.fyihttps://www.jsonl.fyi
Deploys are triggered by Cloudflare's GitHub integration on pushes to main.