Subscription vs API
Why Open Free Max keeps your agent usage on your Max/Pro subscription and never on the metered API bill — and exactly what it refuses to do.
This is the point of OFM. Your usage stays on the plan you already pay for — never a surprise API meter.
Not to be confused with OFM Pro — the licence for the IDE itself ($19.90/mo, 7-day free trial). This page is about your agent provider plan (Claude / Codex / …), which powers the agents and which OFM never bills against. Two separate things.
The two billing paths
Providers split agent usage in two:
- Interactive — a human typing and reading in a terminal. This runs on your normal Max / Pro subscription.
- Programmatic — SDKs, headless
-p/--printruns, ACP and third-party app protocols. This drains a capped credit pool and then bills at API rates.
What OFM does
OFM only ever drives the official CLI in interactive mode: it launches the real binary in an embedded PTY and renders its terminal. To the provider it is indistinguishable from you typing in a shell — because that’s exactly what it is.
What OFM refuses
To protect your bill, OFM deliberately avoids every metered path:
- ❌ The Agent SDK
- ❌ Headless
-p/--printruns - ❌ ACP / third-party app protocols
- ❌ Ever handling your tokens, keys or session auth — that stays with the official binary
This holds no matter how many sessions you run: every pane in Mission Control is a real interactive session, not a headless call.
What this means in practice
Because OFM stays interactive, even a heavy day across many parallel sessions consumes your subscription, not metered credits. The trade-off is that you’ll periodically hit the plan’s usage cap — the session is marked rate-limited and waits for the quota window to reopen, rather than spilling onto the API. See Consumption.