// the find
mourner/flamebearer
A JavaScript CPU trace analysis tool for agents and humans
flamebearer is a CLI tool that reads Chrome DevTools traces and Node .cpuprofile files and prints a text summary of where CPU time went. It's aimed at developers who want quick answers from a profile without opening a GUI, and increasingly at AI agents running automated performance optimization loops.
The text-only output is a genuine design win — piping profile results into an AI context or diff is actually practical. Source map support is automatic and handles the common cases (sibling .map files, inline maps, Chrome-embedded maps). The `--stacks`, `--from/--to`, and `--thread` flags let you drill into a specific function or time slice without re-profiling. The built-in `flamebearer-node` wrapper profiles a script and summarizes it in one command.
The project was dormant from 2018 to 2026, and the current test suite is thin — one fixture per format, no edge case coverage. Chrome trace format is notoriously unstable across DevTools versions; it'll break quietly when Google changes the schema. Only 29 forks despite 1600+ stars suggests people are using it as-is rather than building on it, which means the API surface hasn't been stress-tested. No support for Firefox profiler output or Safari's instruments format, so it's V8-only.