Client-to-server API reference

This documentation covers requests made by a user's browser or mobile app directly to Userfront's server.

For requests made by your server to Userfront's server using your application's API key, see the API reference for server-to-server actions.

The Userfront API is organized around REST. Our API has predictable resource-oriented URLs, accepts JSON-encoded request bodies, returns JSON-encoded responses, and uses standard HTTP response codes, authentication, and verbs.

You can use the Userfront API in test mode, which does not affect your live data. The request origin and JWT access token used to for the request determine whether the request is live mode or test mode.

Userfront uses conventional HTTP response codes to indicate the success or failure of an API request. In general: Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, a charge failed, etc.). Codes in the 5xx range indicate an error with Userfront's servers (these are rare).

Some 4xx errors that could be handled programmatically (e.g. a token is expired) include an error code that briefly explains the error reported.

Errors contain a statusCode, message, and error object.

The message describes what went wrong for the request, while the error object contains additional information about the error.

All endpoints that send emails or SMS messages to users are rate limited to mitigate spam, malicious activity, and accidental misuse.

Requests that exceed rate limits will receive a 429 Rate Limited response.

There are two kinds of rate limit: duplicate request prevention and spam prevention.

Duplicate request prevention:

Userfront will not send email or SMS messages to any user more than once in any 2 second interval. If a request was already fulfilled in the last 2 seconds, additional requests will receive a 429 Rate Limited response.

Spam prevention:

Userfront will not send an excessive number of emails or SMS messages to a user. When these spam prevention rate limits are exceeded, the user will be marked as a suspected target of spam or malicious activity, and Userfront will send no further emails or SMS messages for the following 24 hours, and send a 429 Rate Limited response to any further requests to send messages to the email address or phone number.

For newly registered users and existing users whose email address or phone number is not verified, the limits are:

• No more than 10 messages will be sent within any 10-minute period.
• No more than 20 messages will be sent within any 24-hour period.

When sending to an existing user's confirmed email address or phone number, the limits are:

• No more than 20 messages will be sent within any 10-minute period.

To opt any particular user account out of rate limiting - for example, user accounts used in development and automated testing - please contact support with the user IDs to be opted out.

To match live mode behavior, rate limits are enforced in test mode, even though Userfront does not send emails or SMS messages in test mode.

These actions are related to sign up such as signing up with a password, passwordless, with SSO and using customer data.

Register a new user with an email and password.

Register a new user with an email, and send them a login link email.

If the user already exists, sends them a login link email. See send login link email.

In test mode, Userfront does not send emails. See test mode note.

By default, Userfront sends new users a welcome email to confirm their account. The link in this email contains a uuid and token and works the same way as a login link.

You can disable this email with the options.noSignupEmail parameter above.

In test mode, Userfront does not send emails. Instead, the API response will contain a link attribute that can be followed directly to log in.

In test mode, Userfront does not send emails. Instead, the API response will contain a link attribute that can be followed directly to log in.

Authenticate by visiting a link to an SSO provider. The SSO provider must be configured on the Authentication page in the dashboard.

A user will be signed up using the email provided during SSO authentication.

#URL parameters

• apple
• azure
• facebook
• github
• google
• linkedin
• okta

#Query parameters

Authenticate by visiting a link to an SSO provider. The SSO provider must be configured on the Authentication page in the dashboard.

Use this endpoint to specify custom user data in the payload. Log in with SSO should be preferred otherwise.

#URL parameters

• apple
• azure
• facebook
• github
• google
• linkedin
• okta

These actions are related to log in such as logging in with a password, a login link, a verification code, a TOTP authenticator, or SSO.

In test mode, Userfront does not send emails. Instead, the API response will contain a link attribute that can be followed directly to log in.

Log in with a password and email/username.

By default, Userfront sends a password reset link email to users when they try to log in with a password but have not yet set a password.

You can disable this email with the options.noResetEmail parameter.

When disabled, the request will return an error with the type "intended_error" for a user who does not yet have a password. This distinguishes the request from a user who has a password; their error would be "bad_request_error".

Generate and send a login link email. If no user exists with the given email, this endpoint creates a new user and sends them a login link.

See also: sign up with passwordless.

In test mode, Userfront does not send emails. See test mode note.

In test mode, Userfront does not send emails. Instead, the API response will contain a link attribute that can be followed directly to log in.

#Generate link credentials without sending email

You can generate login link credentials to use in your own custom emails by using the generate link credentials endpoint.

Log in using the token and uuid from a login link.

Generate and send a 6-digit verification code by SMS or email.

When using a verification code as a 2nd factor, only channel is required. See Using firstFactorToken for more.

In test mode, Userfront does not send SMS or email. See test mode note.

In test mode, Userfront does not send SMS messages or emails. Instead, the API response will contain the verification code directly.

Log in using a 6-digit verification code.

When using a verification code as the 1st factor, the request must use the same channel and phoneNumber / email as were used to generate the verification code.

When using a verification code as the 2nd factor, phoneNumber / email are not required. See Using firstFactorToken for more.

Log in using a code generated by a TOTP authenticator app, or with a single-use backup code.

In addition to either a totpCode or a backupCode, the request must contain either a firstFactorToken in the authorization header, or one of the following in the payload: userId, userUuid, emailOrUsername, email, username, or phoneNumber.

Login with a backupCode works the same way as login with a totpCode.

Each user initially begins with 10 single-use backup codes for TOTP.

If all 10 single-use backup codes are used, the user will have set up TOTP authenticator again, at which time they will receive 10 new codes.

Authenticate by visiting a link to an SSO provider. The SSO provider must be configured on the Authentication page in the dashboard.

A user will be logged in using the email provided during SSO authentication.

#URL parameters

• apple
• azure
• facebook
• github
• google
• linkedin
• okta

#Query parameters

These actions are related to reset password such as logging in with a password, a login link, a verification code, a TOTP authenticator, or SSO.

Generate and send a password reset link email.

In test mode, Userfront does not send emails. See test mode note.

In test mode, Userfront does not send emails. Instead, the API response will contain a link attribute that can be followed directly to reset the user's password.

#Generate link credentials without sending email

You can generate password reset link credentials to use in your own custom emails by using the generate link credentials endpoint.

Reset a user's password using the token and uuid from a password reset link.

Upon success, returns a JWT access token so that the user can log in directly.

Logged in actions allow a logged in user to perform actions on their own user record.

These actions are for updating existing items such as reading user info, updating a user, or verifying an email.

Read detailed information about the logged in user.

The request must include the user's valid JWT access token in the Authorization header.

Details of the session associated with the authorization header's JWT.

The request must include the user's valid JWT access token in the Authorization header.

Read all sessions for the logged in user.

The request must include the user's valid JWT access token in the Authorization header.

Update a user's password using their valid JWT access token and their existing password.

The request must include a valid JWT access token in the Authorization header.

#If no password exists

If the user does not have a password (for example, if they logged in via SSO), the existingPassword field is ignored, and Userfront sets the password based on the password field alone.

To update a user's own email address, send the new email address to the Verify an email address endpoint.

This will generate a link the user can click to verify their new email address. They will retain their old email address until the link is clicked.

Read a user's TOTP information, including their QR code image and their remaining single-use backup codes.

The request must include a valid JWT access token or firstFactorToken in the Authorization header.

The qrCode attribute is a base-64 PNG image that can be displayed directly to the user.

Each user initially begins with 10 single-use backup codes for TOTP.

You should display these backup codes to the user so that they can store them in case they lose access to their authenticator device.

If all 10 single-use backup codes are used, the user will have to re-pair their authenticator device, at which time they will receive 10 new codes.

Remove TOTP authenticator from a user's account.

The request must contain the user's valid JWT access token in the authorization header.

Verify a user's email address by emailing them a link (default) or 6-digit verification code.

After a user verifies their email, their user record is marked isEmailConfirmed: true.

To change an existing user's email address, the request must include a valid JWT access token in the Authorization header.

When sending a link, use the Log in with login link endpoint to complete verification. When sending a verification code, use the Log in with verification code endpoint to complete verification.

In test mode, Userfront does not send emails. See test mode note.

In test mode, Userfront does not send emails. Instead, the API response will contain a link or verificationCode attribute that can be used directly to log in.

Verify a user's phone number by sending them an SMS with a 6-digit verification code.

This request must include a valid JWT access token in the Authorization header.

After a user submits the verification code to the verification code endpoint, their phone number is verified and can be used in login and MFA flows.

In test mode, Userfront does not send SMS. See test mode note.

In test mode, Userfront does not send SMS messages. Instead, the API response will contain the verification code directly.

These actions are for logging out a user.

Log out a user and invalidate their current session.

In order to invalidate the user's current session, the request must include a valid JWT access token or refresh token in the Authorization header. This token can be expired.

Log out a user and invalidate all of their sessions.

In order to invalidate the user's sessions, the request must include a valid JWT access token or refresh token in the Authorization header. This token can be expired.

Multi-factor authentication (MFA) requires the user to use 2 separate factors when logging in. It is sometimes also called two-factor authentication (2FA)

On Userfront, any factor can be a first factor or a second factor.

#Enable MFA

MFA is enabled by default. To configure MFA options, visit the Auth flows page and configure the factors you want to use.

You can require MFA for individual users or for all users.

#Require MFA for individuals

To require MFA for an individual user, set their isMfaRequired attribute to true using either the user.update() method from the client, or the Update user endpoint from your server.

#Require MFA for all users

To require MFA for all users, visit the Auth flows page and configure the factors you want to use, then select the toggle labeled "Require MFA".

#"MFA required" response

When MFA is required, a user's initial login request returns the "MFA required" response.

This response contains the following:

• firstFactorToken, which can be sent in the header of the second request in order to log in and obtain a JWT access token. See Using firstFactorToken.
• An authentication object, which contains the firstFactor that was used and an array of secondFactors that are valid for the user. For each of these second factors, isConfiguredByUser indicates whether the user has configured the factor, and, if present, isPreferredByUser indicates which factor the user prefers to log in with.
• The isEmailConfirmed and isPhoneNumberConfirmed attributes, which indicate whether the user's email and phone number have been confirmed yet.

#Using firstFactorToken

You should include firstFactorToken in the authorization header, and from there you can use the second factor endpoint(s) as you normally would.

For endpoints that otherwise require a phoneNumber or email in the request body, you can omit these attributes when the firstFactorToken is included in the header, provided the user already has configured their phone number or email, respectively.

#Example: send SMS verification code for 2nd factor

To send an SMS verification code during the MFA login flow, include the firstFactorToken in the authorization header, and make a request to the Send verification code endpoint.

With the firstFactorToken included, the user's phoneNumber is not required.

If the user has not configured any 2nd factors for their account and does not have a phoneNumber yet, you can include the desired phoneNumber in the payload and it will be added to the user's account upon successful login.

#Example: log in with SMS verification code as 2nd factor

To log in with SMS verification code during the MFA login flow, include the firstFactorToken in the authorization header, and make a request to the Log in with verification code endpoint.

With the firstFactorToken included, the response will contain the user's JWT access token for login.

#Example: read TOTP authenticator information for 2nd factor

To set up TOTP authenticator during the MFA login flow, include the firstFactorToken in the authorization header, and make a request to the Set up TOTP authenticator endpoint.

For users who have not yet set up TOTP, this will return their qrCode and backupCodes, which can be used for TOTP login.

#Example: log in with TOTP authenticator as 2nd factor

To log in with TOTP authenticator during the MFA login flow, include the firstFactorToken in the authorization header, and make a request to the Log in with TOTP authenticator endpoint.

With the firstFactorToken included, the response will contain the user's JWT access token for login.

There are three endpoints to log users in & out using SAML.

View the SAML set up guide to set up your service provider in the Userfront dashboard.

You will need to obtain a SAML token with a valid JWT access token in the Authorization header. You will then use the token to complete the SAML flow using either of the endpoints below to log a user in or out:

• GET /v0/auth/saml/idp/login
• GET /v0/auth/saml/idp/logout

Complete SAML login with token.

When a service provider requests your identity provider's Login URL, the Userfront API will redirect the client to your After-logout path where you will obtain a token using the user's JWT access token as specified in Generate SAML token.

The response is a self-submitting form containing the SAML response which sends a POST request to the service provider to complete the login process.

#Payload parameters

Complete SAML logout with token.

When a service provider requests your identity provider's Logout URL, the Userfront API will redirect the client to your After-logout path where you will obtain a token using the user's JWT access token as specified in Generate SAML token.

The response is a self-submitting form containing the SAML response which sends a POST request to the service provider to complete the logout process.

#Query parameters

Send a user's valid refresh token to obtain a new JWT access token.

The request must include a valid refresh token in the Authorization header.