https://api.outcrawl.ai/v1 and on the MCP server alike. An OAuth token works where it was issued for: the token outcrawl login gets calls the API, and the token an MCP client gets calls the MCP server. This page is about the HTTP header itself; for signing in to the console, see console authentication.
OUTCRAWL_API_KEY for CI and anything headless; it also takes priority over a stored CLI login, so a script always gets a predictable credential regardless of who is signed in on that machine.
In the SDKs
Both SDKs send this header for you. Construct the client with no key and it readsOUTCRAWL_API_KEY from the environment; pass one in (apiKey in TypeScript, api_key in Python) and that key is used instead. With neither, the constructor throws a TypeError that names the variable, before any request is made.