Fivetran REST API uses Basic auth with base64 of API key and secret

Build the Authorization header as Basic base64(API_KEY value API_SECRET) for every Fivetran REST call; there is no bearer-token alternative on the management API. Keep the key and secret in a secret manager and inject them at runtime; rotate on demand from the Fivetran dashboard and update the stored secret, not your code. If a call returns 401, check the key-secret pair and its rotation state before assuming the endpoint is wrong.

Context: Fivetran Connector SDK tooling docs (official fivetran/connector_sdk_tools repo): documents that the REST API authenticates with HTTP Basic where the base64 value encodes {api_key}:{api_secret} using the Fivetran API key and secret. The api_secret is a real credential: treat it like a password, store it in a secret manager, and never print it in build logs or commit it. Fivetran rotates keys on demand, so automation should read the key and secret from the environment or secret store at runtime rather than hardcoding them.