--- title: "Process Introspection Request" method: POST path: "/api/{serviceId}/auth/introspection" tags: ["Introspection Endpoint"] --- # Process Introspection Request `POST /api/{serviceId}/auth/introspection` This API gathers information about an access token. ### Description This API is supposed to be called from within the implementations of protected resource endpoints of the authorization server implementation in order to get information about the access token which was presented by the client application. In general, a client application accesses a protected resource endpoint of a service with an access token, and the implementation of the endpoint checks whether the presented access token has enough privileges (= scopes) to access the protected resource before returning the protected resource to the client application. To achieve this flow, the endpoint implementation has to know detailed information about the access token. Authlete `/auth/introspection` API can be used to get such information. The response from `/auth/introspection` API has some parameters. Among them, it is `action` parameter that the authorization server implementation should check first because it denotes the next action that the authorization server implementation should take. According to the value of `action`, the authorization server implementation must take the steps described below. **INTERNAL\_SERVER\_ERROR** When the value of `action` is `INTERNAL\_SERVER\_ERROR`, it means that the request from the authorization server implementation was wrong or that an error occurred in Authlete. In either case, from the viewpoint of the client application, it is an error on the server side. Therefore, the service implementation should generate a response to the client application with HTTP status of "500 Internal Server Error". Authlete recommends `application/json` as the content type although OAuth 2.0 specification does not mention the format of the error response when the redirect URI is not usable. The value of `responseContent` is a string which describes the error in the format of [RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750) (OAuth 2.0 Bearer Token Usage), so if the protected resource of the service implementation wants to return an error response to the client application in the way that complies with RFC 6750 (in other words, if `accessTokenType` configuration parameter of the service is Bearer), the value of `responseContent` can be used as the value of `WWW-Authenticate` header. The following is an example response which complies with RFC 6750. ``` HTTP/1.1 500 Internal Server Error Content-Type: application/json Cache-Control: no-store Pragma: no-cache {responseContent} ``` **BAD\_REQUEST** When the value of `action` is `BAD\_REQUEST`, it means that the request from the client application does not contain an access token (= the request from the authorization server implementation to Authlete does not contain `token` request parameter). A response with HTTP status of "400 Bad Request" must be returned to the client application and the content type must be `application/json`. The value of `responseContent` is a string which describes the error in the format of [RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750) (OAuth 2.0 Bearer Token Usage), so if the protected resource of the service implementation wants to return an error response to the client application in the way that complies with RFC 6750 (in other words, if `accessTokenType` configuration parameter of the service is `Bearer`), the value of `responseContent` can be used as the value of `WWW-Authenticate` header. The following is an example response which complies with RFC 6750. ``` HTTP/1.1 400 Bad Request WWW-Authenticate: {responseContent} Cache-Control: no-store Pragma: no-cache ``` **UNAUTHORIZED** When the value of `action` is `UNAUTHORIZED`, it means that the access token does not exist or has expired. The value of `responseContent` is a string which describes the error in the format of RFC 6750 (OAuth 2.0 Bearer Token Usage), so if the protected resource of the service implementation wants to return an error response to the client application in the way that complies with [RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750) (in other words, if `accessTokenType` configuration parameter of the service is `Bearer`), the value of `responseContent` can be used as the value of `WWW-Authenticate` header. The following is an example response which complies with RFC 6750. ``` HTTP/1.1 401 Unauthorized WWW-Authenticate: {responseContent} Cache-Control: no-store Pragma: no-cache ``` **FORBIDDEN** When the value of `action` is `FORBIDDEN`, it means that the access token does not cover the required scopes or that the subject associated with the access token is different from the subject contained in the request. A response with HTTP status of "400 Bad Request" must be returned to the client application and the content type must be `application/json`. The value of `responseContent` is a string which describes the error in the format of [RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750) (OAuth 2.0 Bearer Token Usage), so if the protected resource of the service implementation wants to return an error response to the client application in the way that complies with RFC 6750 (in other words, if `accessTokenType` configuration parameter of the service is Bearer), the value of `responseContent` can be used as the value of `WWW-Authenticate` header. The following is an example response which complies with RFC 6750. ``` HTTP/1.1 403 Forbidden WWW-Authenticate: {responseContent} Cache-Control: no-store Pragma: no-cache ``` **OK** When the value of `action` is `OK`, it means that the access token which the client application presented is valid (= exists and has not expired). The implementation of the protected resource endpoint is supposed to return the protected resource to the client application. When action is `OK`, the value of `responseContent` is `"Bearer error=\"invalid\_request\""`. This is the simplest string which can be used as the value of `WWW-Authenticate` header to indicate "400 Bad Request". The implementation of the protected resource endpoint may use this string to tell the client application that the request was bad (e.g. in case necessary request parameters for the protected resource endpoint are missing). However, in such a case, the implementation should generate a more informative error message to help developers of client applications. The following is an example error response which complies with RFC 6750. ``` HTTP/1.1 400 Bad Request WWW-Authenticate: {responseContent} Cache-Control: no-store Pragma: no-cache ``` Basically, The value of `responseContent` is a string which describes the error in the format of [RFC 6750](https://datatracker.ietf.org/doc/html/rfc6750) (OAuth 2.0 Bearer Token Usage). So, if the service has selected `Bearer` as the value of `accessTokenType` configuration parameter, the value of `responseContent` can be used directly as the value of `WWW-Authenticate` header. However, if the service has selected another different token type, the service has to generate error messages for itself. \_**JWT-based access token**\_ Since version 2.1, Authlete provides a feature to issue access tokens in JWT format. This feature can be enabled by setting a non-null value to the `accessTokenSignAlg` property of the service (see the description of the Service class for details). `/api/auth/introspection` API can accept access tokens in JWT format. However, note that the API does not return information contained in a given JWT-based access token but returns information stored in the database record which corresponds to the given JWT-based access token. Because attributes of the database record can be modified after the access token is issued (for example, by using `/api/auth/token/update` API), information returned by `/api/auth/introspection` API and information the given JWT-based access token holds may be different. ## Path parameters - `serviceId` string, required ## Request body - IntrospectionRequest - `token` string, required — An access token to introspect. - `scopes` string[] — A string array listing names of scopes which the caller (= a protected resource endpoint of the service) requires. When the content type of the request from the service is `application/x-www-form-urlencoded`, the format of `scopes` is a space-separated list of scope names. If this parameter is a non-empty array and if it contains a scope which is not covered by the access token,`action=FORBIDDEN` with `error=insufficient_scope` is returned from Authlete. - `subject` string — A subject (= a user account managed by the service) whom the caller (= a protected resource endpoint of the service) requires. If this parameter is not `null` and if the value does not match the subject who is associated with the access token, `action=FORBIDDEN` with `error=invalid_request` is returned from Authlete. - `clientCertificate` string — Client certificate in PEM format, used to validate binding against access tokens using the TLS client certificate confirmation method. - `dpop` string — `DPoP` header presented by the client during the request to the resource server. The header contains a signed JWT which includes the public key that is paired with the private key used to sign the JWT. See [OAuth 2.0 Demonstration of Proof-of-Possession at the Application Layer (DPoP)](https://datatracker.ietf.org/doc/html/draft-ietf-oauth-dpop) for details. - `htm` string — HTTP method of the request from the client to the protected resource endpoint. This field is used to validate the `DPoP` header. See [OAuth 2.0 Demonstration of Proof-of-Possession at the Application Layer (DPoP)](https://datatracker.ietf.org/doc/html/draft-ietf-oauth-dpop) for details. - `htu` string — URL of the protected resource endpoint. This field is used to validate the `DPoP` header. See [OAuth 2.0 Demonstration of Proof-of-Possession at the Application Layer (DPoP)](https://datatracker.ietf.org/doc/html/draft-ietf-oauth-dpop) for details. - `resources` string[] — The resources specified by the `resource` request parameters in the token request. See "Resource Indicators for OAuth 2.0" for details. - `acrValues` string[] — Authentication Context Class Reference values one of which the user authentication performed during the course of issuing the access token must satisfy. - `maxAge` integer — The maximum authentication age which is the maximum allowable elapsed time since the user authentication was performed during the course of issuing the access token. - `requiredComponents` string[] — HTTP Message Components required to be in the signature. If absent, defaults to [ "@method", "@target-uri", "authorization" ]. - `uri` string — The full URL of the userinfo endpoint. - `message` string — The HTTP message body of the request, if present. - `headers` Pair[] — HTTP headers to be included in processing the signature. If this is a signed request, this must include the Signature and Signature-Input headers, as well as any additional headers covered by the signature. - `key` string — The key part. - `value` string — The value part. - `targetUri` string — The target URI of the resource request, including the query part, if any. This parameter is used as the value of the @target-uri derived component for HTTP message signatures [RFC 9421 HTTP Message Signatures, Section 2.2.2. Target URI](https://www.rfc-editor.org/rfc/rfc9421.html#section-2.2.2)). Additionally, other derived components such as `@authority`, `@scheme`, `@path`, `@query` and `@query-param` are computed from this parameter. When this parameter is omitted, the value of the `htu` parameter is used. The `htu` parameter represents the URL of the resource endpoint, which is identical to the target URI of the resource request as long as the request does not include a query component. Conversely, if the resource request includes a query component, the value of the `htu` parameter will not match the target URI, and in that case, the HTTP message signature verification will fail. If neither this `targetUri` parameter nor the `htu` parameter is specified, the target URI is considered unavailable. If HTTP message signing requires the target-uri derived component or other derived components computed based on the target URI, the HTTP message signature verification will fail. - `dpopNonceRequired` boolean — The flag indicating whether to check if the DPoP proof JWT includes the expected `nonce` value. If this request parameter is set to `true` or if the service's `dpopNonceRequired` property is set to `true`, the `/auth/introspection` API checks if the DPoP proof JWT includes the expected `nonce` value. In this case, the response from the `/auth/introspection` API will include the `dpopNonce` response parameter, which should be used as the value of the DPoP-Nonce HTTP header. - `requestBodyContained` boolean — The flag indicating whether the resource request contains a request body. When the resource request must comply with the HTTP message signing requirements defined in the FAPI 2.0 Message Signing specification, the `"content-digest"` component identifier must be included in the signature base of the HTTP message signature (see [RFC 9421 HTTP Message Signatures](https://www.rfc-editor.org/rfc/rfc9421.html)) if the resource request contains a request body. When this `requestBodyContained` parameter is set to `true`, Authlete checks whether `"content-digest"` is included in the signature base, if the FAPI profile applies to the resource request. ## Response `200` - IntrospectionResponse - `resultCode` string — The code which represents the result of the API call. - `resultMessage` string — A short message which explains the result of the API call. - `action` 'INTERNAL_SERVER_ERROR' | 'BAD_REQUEST' | 'UNAUTHORIZED' | 'FORBIDDEN' | 'OK' — The next action that the authorization server implementation should take. - `responseContent` string — The content that the authorization server implementation can use as the value of `WWW-Authenticate` header on errors. - `clientId` integer — The client ID. - `clientIdAlias` string — The client ID alias when the token request was made. If the client did not have an alias, this parameter is `null`. Also, if the token request was invalid and it failed to identify a client, this parameter is `null`. - `clientIdAliasUsed` boolean — The flag which indicates whether the client ID alias was used when the token request was made. `true` if the client ID alias was used when the token request was made. - `expiresAt` integer — The time at which the access token expires. The value is represented in milliseconds since the Unix epoch (1970-01-01). - `subject` string — The subject who is associated with the access token. The value of this property is `null` if the access token was issued using the flow of [Client Credentials Grant](tools.ietf.org/html/rfc6749#section-4.4). - `scopes` string[] — The scopes covered by the access token. - `existent` boolean — `true` if the access token exists. - `usable` boolean — true` if the access token is usable (= exists and has not expired). - `sufficient` boolean — `true` if the access token exists. - `refreshable` boolean — `true` if the access token can be refreshed using the associated refresh token which had been issued along with the access token. `false` if the refresh token for the access token has expired or the access token has no associated refresh token. - `properties` Property[] — The extra properties associated with the access token. - `key` string — The key part. - `value` string — The value part. - `hidden` boolean — The flag to indicate whether this property hidden from or visible to client applications. If `true`, this property is hidden from client applications. Otherwise, this property is visible to client applications. - `certificateThumbprint` string — The client certificate thumbprint used to validate the access token. - `resources` string[] — The target resources. This represents the resources specified by the `resource` request parameters or by the `resource` property in the request object. See "Resource Indicators for OAuth 2.0" for details. - `accessTokenResources` string[] — The target resources this proeprty holds may be the same as or different from the ones `resource` property holds. In some flows, the initial request and the subsequent token request are sent to different endpoints. Example flows are the Authorization Code Flow, the Refresh Token Flow, the CIBA Ping Mode, the CIBA Poll Mode and the Device Flow. In these flows, not only the initial request but also the subsequent token request can include the `resource` request parameters. The purpose of the `resource` request parameters in the token request is to narrow the range of the target resources from the original set of target resources requested by the preceding initial request. If narrowing down is performed, the target resources holded by the `resource` proeprty and the ones holded by this property are different. This property holds the narrowed set of target resources. See "Resource Indicators for OAuth 2.0" for details. - `authorizationDetails` AuthzDetails — The authorization details. This represents the value of the `authorization_details` request parameter in the preceding device authorization request which is defined in "OAuth 2.0 Rich Authorization Requests". - `elements` AuthorizationDetailsElement[] — Elements of this authorization details. - `type` string, required — The type of this element. From _"OAuth 2.0 Rich Authorization Requests"_: _"The type of authorization data as a string. This field MAY define which other elements are allowed in the request. This element is REQUIRED."_ This property is always NOT `null`. - `locations` string[] — The resources and/or resource servers. This property may be `null`. From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the location of the resource or resource server. This is typically composed of URIs."_ This property may be `null`. - `actions` string[] — The actions. From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the kinds of actions to be taken at the resource. The values of the strings are determined by the API being protected."_ This property may be `null`. - `dataTypes` string[] — From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the kinds of data being requested from the resource."_ This property may be `null`. - `identifier` string — The identifier of a specific resource. From _"OAuth 2.0 Rich Authorization Requests"_: _"A string identifier indicating a specific resource available at the API."_ This property may be `null`. - `privileges` string[] — The types or levels of privilege. From "OAuth 2.0 Rich Authorization Requests": _"An array of strings representing the types or levels of privilege being requested at the resource."_ This property may be `null`. - `otherFields` string — The RAR request in the JSON format excluding the pre-defined attributes such as `type` and `locations`. The content and semantics are specific to the deployment and the use case implemented. - `serviceAttributes` Pair[] — The attributes of this service that the client application belongs to. - `key` string — The key part. - `value` string — The value part. - `clientAttributes` Pair[] — The attributes of the client. - `key` string — The key part. - `value` string — The value part. - `scopeDetails` Scope[] — The scopes property of this class is a list of scope names. The property does not hold information about scope attributes. This scopeDetails property was newly created to convey information about scope attributes. - `name` string — The name of the scope. - `defaultEntry` boolean — `true` to mark the scope as default. Scopes marked as default are regarded as requested when an authorization request from a client application does not contain scope request parameter. - `description` string — The description about the scope. - `descriptions` TaggedValue[] — The descriptions about this scope in multiple languages. - `tag` string — The language tag part. - `value` string — The value part. - `attributes` Pair[] — The attributes of the scope. - `key` string — The key part. - `value` string — The value part. - `grantId` string — The value of the `grant_id` request parameter of the device authorization request. The `grant_id` request parameter is defined in [Grant Management for OAuth 2.0](https://openid.net/specs/fapi-grant-management.html) , which is supported by Authlete 2.3 and newer versions. - `grant` Grant - `scopes` GrantScope[] - `scope` string — Space-delimited scopes. - `resource` string[] — List of resource indicators. - `claims` string[] — The claims associated with the Grant. - `authorizationDetails` AuthzDetails — The authorization details. This represents the value of the `authorization_details` request parameter in the preceding device authorization request which is defined in "OAuth 2.0 Rich Authorization Requests". - `elements` AuthorizationDetailsElement[] — Elements of this authorization details. - `type` string, required — The type of this element. From _"OAuth 2.0 Rich Authorization Requests"_: _"The type of authorization data as a string. This field MAY define which other elements are allowed in the request. This element is REQUIRED."_ This property is always NOT `null`. - `locations` string[] — The resources and/or resource servers. This property may be `null`. From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the location of the resource or resource server. This is typically composed of URIs."_ This property may be `null`. - `actions` string[] — The actions. From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the kinds of actions to be taken at the resource. The values of the strings are determined by the API being protected."_ This property may be `null`. - `dataTypes` string[] — From _"OAuth 2.0 Rich Authorization Requests"_: _"An array of strings representing the kinds of data being requested from the resource."_ This property may be `null`. - `identifier` string — The identifier of a specific resource. From _"OAuth 2.0 Rich Authorization Requests"_: _"A string identifier indicating a specific resource available at the API."_ This property may be `null`. - `privileges` string[] — The types or levels of privilege. From "OAuth 2.0 Rich Authorization Requests": _"An array of strings representing the types or levels of privilege being requested at the resource."_ This property may be `null`. - `otherFields` string — The RAR request in the JSON format excluding the pre-defined attributes such as `type` and `locations`. The content and semantics are specific to the deployment and the use case implemented. - `forExternalAttachment` boolean — the flag which indicates whether the access token is for an external attachment. - `consentedClaims` string[] — the claims that the user has consented for the client application to know. - `grantType` 'AUTHORIZATION_CODE' | 'IMPLICIT' | 'PASSWORD' | 'CLIENT_CREDENTIALS' | 'REFRESH_TOKEN' | 'CIBA' | 'DEVICE_CODE' | 'TOKEN_EXCHANGE' | 'JWT_BEARER' | 'PRE_AUTHORIZED_CODE' — The grant type of the access token when the access token was created. - `acr` string — The Authentication Context Class Reference of the user authentication that the authorization server performed during the course of issuing the access token. - `authTime` integer — The time when the user authentication was performed during the course of issuing the access token. - `clientEntityId` string — The entity ID of the client. - `clientEntityIdUsed` boolean — Flag which indicates whether the entity ID of the client was used when the request for the access token was made. - `forCredentialIssuance` boolean — The flag indicating whether the token is for credential issuance. - `cnonce` string — The c_nonce - `cnonceExpiresAt` integer — The time at which the `c_nonce` expires. - `issuableCredentials` string — The credentials that can be obtained by presenting the access token. - `dpopNonce` string — The expected nonce value for DPoP proof JWT, which should be used as the value of the `DPoP-Nonce` HTTP header. - `responseSigningRequired` boolean — The flag indicating whether the HTTP response from the protected resource endpoint must include an HTTP message signature ([RFC 9421 HTTP Message Signatures](https://www.rfc-editor.org/rfc/rfc9421.html)) in compliance with [FAPI 2.0 Message Signing](https://openid.bitbucket.io/fapi/fapi-2_0-message-signing.html). When this response parameter is `true`, the HTTP response from the protected resource endpoint must include the `Signature` and `Signature-Input` HTTP fields. - `metadataDocumentLocation` string, uri — The location of the client's metadata document that was used to resolve client metadata. This property is set when client metadata was retrieved via the [OAuth Client ID Metadata Document](https://datatracker.ietf.org/doc/draft-ietf-oauth-client-id-metadata-document/) (CIMD) mechanism. - `metadataDocumentUsed` boolean — Flag indicating whether a metadata document was used to resolve client metadata for this request. When `true`, the client metadata was retrieved via the CIMD mechanism rather than from the Authlete database. ## Other responses - `400` - `401` - `403` - `500` ## Changes - **2025-12-18** `504771740022` — 2 info - added the optional property `metadataDocumentLocation` to the response with the `200` status - added the optional property `metadataDocumentUsed` to the response with the `200` status [Change history](https://skmtc.dev/authlete/apis/authlete-api/changes/api/:serviceId/auth/introspection/post.md) --- [API](https://skmtc.dev/authlete/apis/authlete-api.md) · [All operations](https://skmtc.dev/authlete/apis/authlete-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/authlete/authlete-api/revisions/8a534bc68775/schema)