Resource Owner Password Credentials

The Resource Owner Password Credentials (ROPC) grant allows a client to exchange a username and password directly for tokens, without going through the browser authorization flow.

Caution

ROPC is a legacy grant type. It requires the client to handle user credentials directly, which means it cannot support passkeys or SSO sessions. Only use it for trusted first-party CLI tools or migration scenarios where a browser redirect is not possible.

Request

curl -X POST https://auth.example.com/oauth2/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=password" \
  -d "username=alice" \
  -d "password=secret" \
  -d "client_id=my-client-id" \
  -d "scope=openid profile email" \
  -d "totp_code=123456"

Parameters

Parameter	Required	Description
grant_type	Yes	Must be password
username	Yes	The user’s username
password	Yes	The user’s password
client_id	Yes	The client identifier
scope	No	Space-separated list of scopes (defaults to client’s allowed scopes, or openid profile email)
totp_code	Conditional	Required when MFA is enforced (see MFA enforcement below)

Response:

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...",
  "id_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...",
  "refresh_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 900,
  "scope": "openid profile email"
}

Enabling for a client

The client must have password in its grant_types. When registering:

curl -X POST https://auth.example.com/oauth2/register \
  -H "Authorization: Bearer $ADMIN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "client_name": "My CLI Tool",
    "redirect_uris": ["http://localhost"],
    "grant_types": ["password", "refresh_token"],
    "client_type": "public"
  }'

MFA enforcement

MFA is fully enforced in the ROPC flow. When the global require_mfa setting is enabled or the user has TOTP enrolled, the totp_code parameter is required. The server responds with specific error codes:

• mfa_required (HTTP 403) — returned when TOTP is enrolled but totp_code was not provided, or when require_mfa is enabled but the user has not yet enrolled in TOTP (the user must enroll via the browser login flow first)
• invalid_mfa_code (HTTP 403) — returned when the provided totp_code is incorrect

Only TOTP codes are supported in the ROPC flow. Email OTP is not available because there is no interactive session to complete the challenge. See Multi-Factor Authentication for details on MFA setup and enrollment.

Limitations

• Passkey authentication is not available — ROPC only supports username/password
• Email OTP is not available — only TOTP codes can be used for MFA in ROPC
• No SSO session is created — each ROPC token exchange is independent
• Account lockout still applies — repeated failed password attempts will lock the account