A concrete example
You connect Claude to n8n: n8n doesn't know your full account, it only uses the API key you hand it.
Why it matters
The moment AI leaves the chat and enters an automation, the API key becomes the main entry point.
You see it in the Anthropic, OpenAI, Resend, Supabase, and Vercel consoles, or in the connection fields of a no-code tool.
Don't mix it up with
.env file: A .env file keeps a project's sensitive keys and settings out of the visible code.
Token: A token is a small chunk of text the AI counts to measure what it reads, writes, and bills.
Common mistakes
- Pasting an API key into a public document.
- Reusing the same key across all your tools.
- Forgetting to set a spending limit.
Quick checklist
- First I check whether the word names a concept, a tool, a risk, or a metric.
- I tie it to a concrete case: You connect Claude to n8n: n8n doesn't know your full account, it only uses the API key you hand it.
- I keep the main trap in mind: Pasting an API key into a public document.
Quick questions
What is API key in AI?
An API key is a technical password that lets a tool call an AI service on your behalf.
Where will I run into API key?
You see it in the Anthropic, OpenAI, Resend, Supabase, and Vercel consoles, or in the connection fields of a no-code tool.
Which word should I read next?
Start with .env file, Token, Vercel environment variables.