generated: '2026-07-18'
method: searched
source: https://chain.com/documentation/authentication
docs: https://chain.com/documentation/authentication
summary:
  types: [apiKey]
  api_key_in: [header]
  scheme: bearer
  oauth2_flows: []
notes: >-
  Chain uses API-key authentication passed as a Bearer token in the Authorization header. Keys are
  environment-scoped by prefix: sk_sandbox_ for the testing environment and sk_live_ for production
  (live keys move real money). No OAuth is documented.
schemes:
- name: bearerApiKey
  type: http
  scheme: bearer
  in: header
  header: Authorization
  format: 'Bearer [example key] (live) / Bearer [example key] (sandbox)'
  key_prefixes:
    live: sk_live_
    sandbox: sk_sandbox_
headers:
- name: Authorization
  required: true
  description: Bearer token containing the API key.
- name: Content-Type
  required: true
  description: Must be application/json for request bodies.
- name: X-Business-Id
  required: false
  description: Required when managing multiple businesses under one account.
- name: X-Idempotency-Key
  required: false
  description: Unique key for safe request retries.