Which agents burnlog counts
Two mechanisms, and which one applies depends on whether the agent writes its usage somewhere readable. Every page below says what burnlog measures, how, and where it stops.
Read from local logs
The agent already writes its own usage to disk. Nothing to configure, and your first run counts history you already have.
Read directly from the session logs Claude Code already writes. Nothing to configure, and it works retroactively on history you've already accumulated.
Read directly from ~/.codex/sessions. Like Claude Code, it needs no key and no proxy, and it counts the history you already have.
Counted at the wire
No readable log, so burnlog reads the usage field off the API response instead — the provider's own number, not an estimate.
Depends entirely on whose key you're spending. Your own API key, counted exactly. Cursor's included subscription, not countable by anything on your machine — and any tracker claiming otherwise is guessing.
Counted through burnlog wrap. One prefix on the command you were going to run anyway, and every call is measured from the response Google sends back.
Counted through burnlog wrap, on whichever provider aider is configured against — including two providers in the same session.
Counted through burnlog wrap. No adapter, no waiting for burnlog to add support for the model you switched to this morning.