Short answerAn API key is a secret password that lets software use an AI provider's models and bills your account. Anyone with your key can spend your money, so treat it like a bank password.
Why a bot needs one
ChatGPT Custom GPTs ran on OpenAI's own system and plan. A replacement bot outside ChatGPT calls a model provider (OpenAI, Anthropic and others) over the internet, and the provider needs to know whose account to charge. The key is how it knows.
Key facts
- It is long text, often starting with a provider prefix.
- Providers usually show it once; copy it into a safe place.
- Usage is billed to the account that made the key.
- You can create several keys and delete one without affecting the others.
Rules
- Never post it publicly or send it in chat.
- Set spending limits: OpenAI, Anthropic.
- Rotate it if you think it leaked: safety checklist.
Related: what key errors mean and how hosting uses your key.
Need your GPT running again without ChatGPT?
GPT Migrator can host your instructions and files as a standalone chat page for $47 per month. You bring your own OpenAI or Anthropic API key. It answers from your instructions and files and does not run GPT Actions.
See how hosting worksRelated guides
Sources
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