Ordinary API-key requests are not included in ChatGPT Plus. ChatGPT subscriptions and OpenAI API-platform billing are separate. Using the same email address does not combine them into one allowance. 12
Check how the tool authenticates
If a plugin, script or automation asks for an API key, check the API project’s billing, usage limits and model access. Do not assume your existing Plus payment covers those calls.
There is a current distinction worth knowing: supported tools using Sign in with ChatGPT, with separately approved allowance sharing, may use an eligible subscription’s included allowance. That does not make ordinary API-key requests free, and connecting another tool does not automatically create extra allowance. 1
Before connecting anything
Look at the authentication method, not just a ChatGPT logo in the marketing. Establish which account or project pays for the requests. Start with a small test and check the relevant usage view afterward.
Do not give an arbitrary website your ChatGPT password or paste an API key into a conversation. For API integrations, use a narrowly scoped key in a controlled server-side setup.
The useful rule is: an API key means checking API billing; a ChatGPT sign-in means checking the terms of that specific supported integration. This avoids both surprise charges and the opposite mistake of assuming every third-party workflow must be API-billed.
