CreateOAuth2Token API

Path: /v1/token Request Method: POST Content-Type: application/json or application/x-www-form-urlencoded

This API implements OAuth 2.0 flows for AWS Sign-In CLI clients, supporting both:

1. Authorization code redemption (grant_type=authorization_code) - NOT idempotent
2. Token refresh (grant_type=refresh_token) - Idempotent within token validity window

The operation behavior is determined by the grant_type parameter in the request body:

Authorization Code Flow (NOT Idempotent):

• JSON or form-encoded body with client_id, grant_type=authorization_code, code, redirect_uri, code_verifier
• Returns access_token, token_type, expires_in, refresh_token, and id_token
• Each authorization code can only be used ONCE for security (prevents replay attacks)

Token Refresh Flow (Idempotent):

• JSON or form-encoded body with client_id, grant_type=refresh_token, refresh_token
• Returns access_token, token_type, expires_in, and refresh_token (no id_token)
• Multiple calls with same refresh_token return consistent results within validity window

Authentication and authorization:

• Confidential clients: sigv4 signing required with signin:ExchangeToken permissions
• CLI clients (public): authn/authz skipped based on client_id & grant_type

Note: This operation cannot be marked as @idempotent because it handles both idempotent (token refresh) and non-idempotent (auth code redemption) flows in a single endpoint.