Version 5.x has been out of support since December 13, 2022, and this corresponding section of the documentation is no longer maintained. We strongly recommend upgrading to a supported version.

Authorize Endpoint

The authorize endpoint can be used to request tokens or authorization codes via the browser. This process typically involves authentication of the end-user and optionally consent.

IdentityServer supports a subset of the OpenID Connect and OAuth 2.0 authorize request parameters. For a full list, see here.

Required parameters

  • client_id

    identifier of the client

  • scope

    one or more registered scopes

  • redirect_uri

    must exactly match one of the allowed redirect URIs for that client

  • response_type

    specifies the response type

    • id_token

    • token

    • id_token token

    • code

    • code id_token

    • code id_token token

Optional parameters

  • response_mode

    specifies the response mode

    • query

    • fragment

    • form_post

  • state

    echos back the state value on the token response, this is for round tripping state between client and provider, correlating request and response and CSRF/replay protection. (recommended)

  • nonce

    echos back the nonce value in the identity token (for replay protection)

    Required when identity tokens is transmitted via the browser channel

  • prompt

    • none

      no UI will be shown during the request. If this is not possible (e.g. because the user has to sign in or consent) an error is returned

    • login

      the login UI will be shown, even if the user is already signed-in and has a valid session

  • code_challenge

    sends the code challenge for PKCE

  • code_challenge_method

    • plain

      indicates that the challenge is using plain text (not recommended)

    • S256

      indicates the challenge is hashed with SHA256

  • login_hint

    can be used to pre-fill the username field on the login page

  • ui_locales

    gives a hint about the desired display language of the login UI

  • max_age

    if the user’s logon session exceeds the max age (in seconds), the login UI will be shown

  • acr_values

    allows passing in additional authentication related information - IdentityServer special cases the following proprietary acr_values:

    • idp:name_of_idp

      bypasses the login/home realm screen and forwards the user directly to the selected identity provider (if allowed per client configuration)

    • tenant:name_of_tenant

      can be used to pass a tenant name to the login UI

  • request

    instead of providing all parameters as individual query string parameters, you can provide a subset or all of them as a JWT

  • request_uri

    URL of a pre-packaged JWT containing request parameters

GET /connect/authorize?
    scope=openid email api1&
    response_type=id_token token&

.NET client library

You can use the IdentityModel client library to programmatically create authorize request URLs from .NET code.

var ru = new RequestUrl("");

var url = ru.CreateAuthorizeUrl(
    clientId: "client",
    responseType: "code",
    redirectUri: "",
    scope: "openid");