More than most people expect. Every connected service and plugin loads the description of all its tools into the session, and that is re-read on every turn, whether or not you use any of them.
A real measurement
On the author's Mac, with a typical pile of connectors and plugins switched on, sessions started at about 126,000 tokens before a single message of real work. Worker sessions started with a smaller set of tools on the same machine began at about 66,000.
The figures on this page come from real session logs on the author's Mac, read with Cost Doctor. Your numbers will differ; the pattern usually does not.
That starting size is paid on every turn for the whole life of the session. Compacting does not remove it, because it is loaded fresh each time.
How to see your own number
- In Claude Code: run
/contextat the start of a fresh session. It shows what is taking up the window before you have typed anything. - In the logs: the first reply in a session's log file records how many tokens went in. That is your starting size.
- In Cost Doctor: every session shows "starts at" next to its current size, and any session that starts above your chosen limit is flagged.
How to cut it
- Switch off connectors you are not using in this project. A service with two hundred tools costs you its whole list on every turn, even if you never call one.
- Disable plugins per project instead of leaving every one on everywhere.
- Keep long instruction and memory files short. They are loaded every turn too, though on the measured machine they were under a tenth of the starting size. The tool lists were the bulk.
Why it matters more than it looks
If your sessions start at 126,000 and your work adds a thousand tokens a turn, then for the first hundred turns almost everything you are paying for is overhead. Halving the starting size nearly halves the cost of those turns.
See it on your own sessions
Cost Doctor is a Mac menu bar app that reads the logs Claude Code and Codex already write. It names the session that is using your tokens, says why, and turns your screen red when a check fails while an agent sits waiting. Nothing leaves your Mac.
Download the free trialHow it works14 days free, no account. Then $19 once, plus tax where it applies. For Apple silicon and Intel Macs on macOS 13 or later.