OAuth Client ID Metadata Document

4.1. Credential and Key Material Restrictions

As client metadata documents are publicly accessible, the following restrictions apply to the contents of the Client ID Metadata Document:¶

• the client_secret and client_secret_expires_at properties MUST NOT be used¶

• the token_endpoint_auth_method and token_endpoint_auth_methods_supported properties MUST NOT include client_secret_post, client_secret_basic, client_secret_jwt, or any other method based around a shared symmetric secret¶

• private key material MUST NOT be included in the Client ID Metadata Document; only public keys, such as those published via the jwks or jwks_uri properties, are permitted¶

• The "jwks_uri" and "jwks" parameters MUST NOT both be present in the same request or response, as described in [RFC7591]¶

The above restrictions also apply when using the software_statement parameter, as described in Section 4.3.¶

See Section 5 for more details on establishing client authentication.¶

4.2. Redirect URL Registration

According to [RFC9700], the authorization server MUST require registration of redirect URLs, and MUST ensure that the redirect URL in an authorization request is an exact match (using simple string comparison) of a registered redirect URL. An exception is made for redirect URIs on the loopback network interface, which allow for randomly assigned ports. See Section 4.1.3 of [RFC9700] for details.¶

This method of client information discovery establishes registered redirect URL(s) when the authorization server fetches the contents of the Client ID Metadata Document.¶

This specification is not limited to grant types that use a redirect URL. For grant types that do not involve a redirect URL, such as the Client Credentials Grant, or extension grants such as Token Exchange, the requirements of this section do not apply, since no redirect URL is registered or used. The other mechanisms described in this specification, namely client identification and client metadata discovery, apply regardless of which grant type is used.¶

4.3. Relationship with software_statement

The software_statement parameter defined in [RFC7591] MAY be used together with a Client Identifier URL, for example by including it as a property of the Client ID Metadata Document. Doing so can provide the authorization server with an additional, independently verifiable signal about the client's identity or provenance.¶

Operators combining software statements with this specification should note that the software statement is no longer presented inline by the client during the authorization request; instead, it is retrieved by the authorization server as part of fetching the Client ID Metadata Document. This means the trustworthiness of the software statement's claims depends not only on the issuer's signature over the statement itself, but also on the integrity of the process used to retrieve the Client ID Metadata Document (including the protections described in Section 10.7), as well as the relationship between the client instance and the Client ID Metadata Document. Authorization servers should evaluate whether this combination meets their assurance requirements before relying on software statements delivered this way.¶

4.4. Relationship and Restrictions on URI-based Properties

Many client metadata properties have URI values. For the purposes of this specification, these properties fall into one of two categories:¶

Functional URIs:

URIs that the authorization server dereferences, or uses directly, as part of processing the OAuth protocol. These include the client_id itself, the redirect_uris, and the jwks_uri.¶

Informative URIs:

URIs that are intended to be presented to the end-user, typically on the authorization or consent screen, to provide additional information about the client. These include client_uri, logo_uri, policy_uri, and tos_uri.¶

Properties defined by other specifications that have URI values fall into one of these two categories based on how they are used, as described by the specification that defines them. A property whose value the authorization server dereferences or acts on during protocol processing is a functional URI; a property whose value is only displayed or linked to for the end-user is an informative URI.¶

Authorization servers MAY impose restrictions on functional URIs, such as restricting the redirect_uris to the same origin as the client_id, as discussed in Section 10.2. Authorization servers fetching functional URIs such as jwks_uri are subject to the considerations described in Section 10.7.¶

Informative URIs are not used to establish the identity of the client, and an application's informational website will often be hosted separately from where its Client ID Metadata Document is published. As such, the authorization server MUST NOT require that the client_uri be on the same origin as, or a prefix of, the client_id or any of the redirect_uris.¶

Since informative URIs are under the control of the client and are displayed to the end-user, authorization servers should treat them with the same caution described in Section 5 of [RFC7591] for open client registration. See also Section 10.9 and Section 4.5.¶

4.5. Preventing External Influence of Document Contents

A Client ID Metadata Document is intended to consistently describe one client. Clients MUST NOT derive the contents of a Client ID Metadata Document from untrusted external input. This includes input embedded in path or query components of a Client Identifier URL, as well as request headers, cookies, or information about the requesting user or authorization server. In particular, untrusted external input MUST NOT influence URIs used for protocol operation (Functional URIs), URIs providing information about the client (Informative URIs), or other security-sensitive or user-visible metadata such as client_name, client_uri, logo_uri, policy_uri, or tos_uri.¶

This requirement does not prevent an operator from intentionally updating a Client ID Metadata Document, including performing key rotation, or from publishing intentionally different documents at distinct Client Identifier URLs.¶

5.1. Examples of Client Authentication

This section is non-normative.¶

To establish client authentication using a public key with the private_key_jwt authentication method defined in [OpenID], the client metadata document would contain the following:¶

{
  ...
  "token_endpoint_auth_methods_supported": ["private_key_jwt"],
  "jwks_uri": "https://client.example.com/jwks.json"
  ...
}

This establishes this client as a confidential client, and any communication with the authorization server must include client authentication using private_key_jwt.¶

A client can advertise more than one client authentication method to interoperate with authorization servers that support different methods. In the following example, the client offers private_key_jwt to authorization servers that support it, while remaining usable as a public client for those that do not:¶

{
  ...
  "token_endpoint_auth_methods_supported": ["none", "private_key_jwt"],
  "jwks_uri": "https://client.example.com/jwks.json"
  ...
}

If the authorization server does not support private_key_jwt, then the token endpoint authentication method to be used by the client must be none and the client will be a public client.¶

If the authorization server does support private_key_jwt client authentication, then the client should use the private_key_jwt token endpoint authentication method. If the client were to use none then the authorization server may reject the request with invalid_client.¶

This means the client may either be a public client or confidential client, dependent on the token endpoint authentication method selected for use.¶

6.1. Metadata Discovery Errors

If the authorization server attempts to fetch the Client ID Metadata Document, and fetching the metadata document fails, the authorization server SHOULD abort the authorization request.¶

This document distinguishes two classes of discovery failure: a transient failure (e.g., a network error or timeout, comparable in spirit to the temporarily_unavailable condition in Section 4.1.2.1 of [RFC6749]) and a terminal failure (the document was retrieved but was malformed, or was rejected on trust or validation grounds).¶

A transient failure SHOULD NOT by itself invalidate a Client Identifier URL's previously established trust or outstanding refresh tokens. An authorization server SHOULD NOT discard previously cached valid client metadata on transient failures.¶

A terminal failure caused by a client_id mismatch SHOULD invalidate the client's outstanding refresh tokens immediately.¶

A terminal failure caused by the authorization server's own trust or policy MAY invalidate the client's outstanding refresh tokens immediately, at the authorization server's discretion, consistent with Section 10.5.¶

When a request fails because the Client ID Metadata Document could not be retrieved or was invalid, the authorization server MUST NOT redirect the user agent to the client, as described in Section 4.1.2.1 of [RFC6749], and SHOULD inform the user of the error. At the token endpoint or pushed authorization request endpoint, the authorization server MUST return an invalid_client error, or for a transient failure, an HTTP 503 status code.¶

6.2. Metadata Caching

The authorization server MAY cache the client metadata it discovers at the Client ID Metadata Document URL, including data retrieved from referenced URLs such as the jwks_uri and logo_uri.¶

The authorization server SHOULD respect HTTP cache headers [RFC9111] when caching client metadata. The Expires HTTP header need not be honored, since Cache-Control takes precedence under [RFC9111].¶

The authorization server SHOULD enforce a maximum effective cache duration regardless of the cache directives in the response. The authorization server SHOULD also enforce a minimum effective cache duration when none is otherwise indicated.¶

The authorization server MUST NOT cache error responses. The authorization server also MUST NOT cache documents which are invalid or malformed.¶

The authorization server MAY implement rate limiting or other measures to avoid repeatedly fetching a Client ID Metadata Document URL, even if that results in fetching the URL less often than requested by the cache headers.¶

9.1. Supporting Both Pre-Registered and Unregistered Clients

If an authorization server wishes to support clients using Client ID Metadata Documents as well as clients where the authorization server generates the client_id, it SHOULD ensure that the client_id strings it generates do not start with https://. Given that most implementations of authorization servers generate random values for the client_id, this is not expected to be a problem in practice.¶

The presence of the https:// scheme in a client_id is not by itself a reliable signal of whether a client was registered using this specification, such as if an authorization server issues https:// URLs as client_id values for other purposes like vanity identifiers or stable developer-facing identifiers, without treating them as Client Identifier URLs to be fetched. The determining factor for whether a client_id is subject to this specification is whether the authorization server fetches, or otherwise associates, a Client ID Metadata Document for that client_id. Authorization servers that support both approaches need a reliable way, internal to their own implementation, to distinguish clients registered via this specification from those registered by other means.¶

9.2. Pre-Registering Client Identifier URLs

An authorization server MAY pre-register Client Identifier URLs. This is a valid deployment pattern that leverages the namespacing and key-binding properties of Client Identifier URLs described in this specification, while not relying on the authorization server automatically fetching client metadata at request time. The authorization server SHOULD fetch the Client ID Metadata Document at the URL at the time of establishing this pre-registration, although other means of registering the metadata document are also valid.¶

This deployment pattern is expected to be common in enterprise environments where enterprise customers wish to explicitly onboard particular clients into their environment. The Client Identifier URL can be registered with the identity provider, including establishing client authentication as described in Section 5, where it can behave the same way as a pre-registered client. There is no obligation to support dynamic client onboarding by using the mechanisms described in this document.¶

10.1. Client Identifier URL Confusion Attacks

To prevent token confusion attacks, an authorization server SHOULD reject a Client Identifier URL that is equal, using simple string comparison as defined in Section 6.2.1 of [RFC3986], to its own issuer identifier, or to the identifier of any authorization server or resource server it has a trust relationship with.¶

The Client Identifier URL appears in tokens and assertions as the value of claims such as aud in tokens issued to the client, iss and sub in client authentication assertions ([RFC7523]), and client_id in access tokens and token introspection responses. If the Client Identifier URL equals the identifier of another party, these values become ambiguous, and a token or assertion relating to the client could be accepted by that party as having been issued by, issued to, or being about itself.¶

10.2. Relationship between redirect_uris and client_id

An authorization server may impose restrictions or relationships between the redirect_uris and the client_id, for example to restrict the redirect_uri to the same-origin as the Client ID Metadata Document. Without restrictions like these, there are potential trust and safety issues where the client attempts to impersonate a more well-known client or otherwise act in a way which is malicious or puts the end-user at risk. Restrictions of this kind do not apply to informative URIs such as client_uri, as described in Section 4.4.¶

Having no restrictions on the relationship between redirect_uris and client_id was a common practice with [Solid-OIDC]'s Client ID Documents, so this ability is preserved for backwards compatibility between [Solid-OIDC] and this specification.¶

Some restrictions on redirect_uris can make developer usage of Client ID Metadata Documents difficult. Section 10.13 discusses how a service offered by the authorization server can enable development usage of Client ID Metadata Documents for authorization servers that impose restrictions on the redirect_uri.¶

10.3. Client Authentication Key Material

The particular method of how the client manages the private key is out of scope of this specification, but may include manual provisioning or methods such as "Attestation Based Client Authentication" [I-D.draft-ietf-oauth-attestation-based-client-auth] or "OAuth SPIFFE Client Authentication" [I-D.draft-ietf-oauth-spiffe-client-auth]. For example, the client developer could run a Client Attester Backend, using a native application's platform-specific APIs to authenticate to the backend service, where the private key corresponding to the jwks_uri key is managed by the backend service. This would allow a mobile app to request JWTs from the backend service that the mobile app could then use as client authentication to the authorization server.¶

10.4. Changes in Client Identifier URL

The Client Identifier URL is the client's identity from the perspective of the authorization server. Because OAuth treats two different client_id values as two entirely unrelated clients, a client that changes its Client Identifier URL is, as far as any authorization server is concerned, a brand new client with no relationship to the previous one. Any grants, tokens, or user consent that had been associated with the old URL may not be transferable to the new URL, and users may be prompted to re-authorize as if encountering the client for the first time.¶

Clients should therefore treat their Client Identifier URL with the same degree of stability as they would treat any persistent identity. Operators should plan for the URL to remain resolvable and under their control indefinitely, as loss of control over the URL (for example through domain expiry or reassignment) would allow a third party to assume the client's identity.¶

10.5. Changes in Client Metadata

Authorization servers should be aware that Client ID Metadata Documents can change over time since they are served from URLs under client control. Authorization servers should consider the security implications when metadata properties change, such as redirect_uris, token_endpoint_auth_method, scope, grant_types, jwks, jwks_uri, or display properties like client_name and logo_uri.¶

Significant changes to client metadata may affect the trust relationship between the authorization server and the client, and could impact the validity of previously granted user consent. Authorization servers may choose to invalidate existing grants, require fresh user consent, or implement other policies when certain types of metadata changes are detected. The appropriate response will depend on the authorization server's risk tolerance and operational requirements.¶

10.6. OAuth Phishing Attacks

Authorization servers SHOULD fetch the client_id metadata document provided in the authorization request in order to provide users with additional information about the request, such as the application name and logo. If the server does not fetch the Client ID Metadata Document, then it SHOULD take additional measures to ensure the user is provided with as much information as possible about the request.¶

The authorization server SHOULD display the hostname of the client_id on the authorization interface, in addition to displaying the fetched client information if any. Displaying the hostname helps users know that they are authorizing the expected application.¶

If fetching the Client ID Metadata Document fails for any reason, the client_id URL is the only piece of information the user has as an indication of which application they are authorizing.¶

10.7. Server Side Request Forgery (SSRF) Attacks

Authorization servers fetching the Client ID Metadata Document and resolving URLs contained within it should be aware of possible SSRF attacks. Authorization servers MUST NOT fetch a Client ID Metadata Document URL or any URLs contained within a Client ID Metadata Document that resolve to special-use IP addresses as defined in [RFC6890].¶

Authorization servers SHOULD follow the recommendations in [OWASP.SSRF].¶

Authorization servers deployed for development or testing purposes MAY relax this restriction to allow fetching from loopback addresses when the authorization server itself is also running on a loopback address and the resolved address matches the same loopback interface. Authorization servers MUST NOT apply this exception in production deployments, since doing so would allow an attacker-controlled Client Identifier URL to cause the authorization server to make requests against itself or other services on the loopback interface or special-use IP addresses.¶

Authorization servers SHOULD consider network policies or other measures to prevent making requests to special-use addresses. Authorization servers which support non-http-based URI schemes are at additional risk of SSRF attacks.¶

Authorization servers SHOULD ensure they only fetch or parse URLs with known and supported URI schemes. This can help avoid leading to compromises if a client uses a URI scheme such as javascript: in a metadata property.¶

10.8. Client ID Domain Trust

The authorization server may choose to have its own heuristics and policies around the trust of domain names used as client IDs.¶

For example, the authorization server could require that the first 100 users to authorize a client_id see an additional warning screen before the OAuth consent screen. The authorization server could check attributes of the domain reputation, such as how recently the domain was registered, and put up extra warnings for new domains. An authorization server may also maintain allowlists of trusted domain patterns, such as treating any Client Identifier URL under *.example.com as belonging to a known and trusted operator, and apply reduced friction for clients matching such patterns.¶

10.9. Displaying Logos to End-Users

Authorization servers that wish to display the image at logo_uri to the end-user, such as on the authorization page or on a page where the end-user manages their authorized clients, MUST prefetch the file at logo_uri and MUST serve it to the end-user from servers that the authorization server trusts, rather than referencing the logo_uri directly. See Section 6.2 for considerations related to caching the metadata and logo.¶

Before displaying the file, the authorization server MUST verify that the file contents are a valid image, and that the image satisfies the authorization server's content security policy.¶

Prefetching and serving the logo from a trusted server allows moderation tools to verify the file contents (e.g., preventing usage of logos that look like other logos), and prevents the logo from being dynamically changed to confuse an end-user, or from being served differently to the authorization server than to the end-user. It also prevents the operator of the logo_uri from tracking end-users across domains through requests made by the end-user's browser, as described in Section 11.2.¶

10.10. Presentation of the Client to End-Users

Client metadata properties that describe how the client is presented to the end-user, such as client_name, logo_uri, client_uri, policy_uri, and tos_uri, are asserted by the client. A malicious client can use these properties to impersonate a more well-known client, for example by using another client's name or logo.¶

Authorization servers are not required to display these properties, and MAY apply their own policies when deciding whether and how to present them to the end-user. For example, an authorization server could only display the client_name or logo of clients that have been manually reviewed or that appear on an allowlist, could display a warning alongside these properties for clients that have not been reviewed, or could display only the hostname of the Client Identifier URL as described in Section 10.6. See also Section 10.8 and Section 4.4.¶

10.11. Maximum Response Size for Client ID Metadata Documents

Since the authorization server does not control the size of the Client ID Metadata Document served by the client, it cannot limit the size of the response itself. Instead, authorization servers SHOULD limit the amount of data they read and process when fetching a Client ID Metadata Document, for example by stopping after a maximum number of bytes and treating the response as an error if that limit is reached before the document has been fully read. The recommended maximum size to read is 5 kilobytes.¶

10.12. Resource Indicator Scoping of Persisted Authorization State

Any mechanism an authorization server uses to persist or reuse a prior authorization decision for a client MUST be scoped at least to the pair of Client Identifier URL and resource, consistent with the binding already required of refresh tokens in Section 4.14.2 of [RFC9700].¶

10.13. CIMD Services

This section describes a pattern, referred to as a CIMD Service, through which an authorization server can offer developers a way to obtain Client Identifier URIs for use during development, without requiring the developer to host a publicly accessible document themselves.¶

Operating a CIMD Service has security and reputation implications, since it is effectively acting as a proxy for static client registration for any client it provisions. An authorization server operating a CIMD Service should ensure that clients provisioned this way are clearly distinguished from other clients when presented to end users, and should consider the implications on the trust model described in this specification, since a CIMD Service intermediates the relationship between the client and the authorization server rather than the client publishing its own metadata directly.¶

11.1. Authorization Server Fetch Side Channel

When the authorization server fetches a Client Identifier URL or other URLs referenced within a Client ID Metadata Document, the act of fetching may reveal information about end-user activity to the operator of the server hosting those URLs. For example, the timing and frequency of requests to a Client Identifier URI can indicate when, and how often, users are attempting to authorize with a particular authorization server.¶

Authorization servers that fetch client metadata on every authorization request, rather than relying on cached data, are more susceptible to this side channel. Authorization servers SHOULD respect cache headers as described in Section 6.2 to reduce the frequency of unnecessary fetches.¶

Varying a Client ID Metadata Document based on the requesting user, authorization server, or other request context can amplify this side channel. It can enable a client to track requesters or selectively present misleading metadata that is difficult for users and independent reviewers to detect. Clients must follow the consistency requirements in Section 4.5. Authorization servers SHOULD avoid sending cookies, user-specific information, or unnecessary request headers when fetching Client ID Metadata Documents.¶

11.2. URLs Referenced in Client ID Metadata Documents

Client ID Metadata Documents may contain URLs, such as logo_uri, jwks_uri, policy_uri, or tos_uri, that the authorization server fetches directly or exposes to the end user, for example by rendering them or linking to them in the authorization interface. When these URLs are fetched by the authorization server, or their content is served to the end user's browser, they may create cross-domain tracking opportunities for the operator of the referenced URL.¶

As described in Section 10.9, authorization servers that fetch the content of logo_uri and serve it themselves rather than linking to it directly mitigate the risk of cross-domain tracking through logo requests initiated by the end user's browser. Authorization servers should consider similar precautions for other URLs contained in the Client ID Metadata Document before exposing them to end users.¶

12.1. OAuth Authorization Server Metadata Registry

The following authorization server metadata value is defined by this specification and registered in the IANA "OAuth Authorization Server Metadata" registry established in [RFC8414] (OAuth 2.0 Authorization Server Metadata).¶

• Metadata Name: client_id_metadata_document_supported:¶

• Metadata Description: JSON boolean value specifying whether the authorization server supports retrieving client metadata from a client_id URL.¶

• Change Controller: IETF¶

• Specification Document: Section 8 of [draft-ietf-oauth-client-id-metadata-document-03]¶

13.1. Normative References

[OpenID.RPMetadataChoices]

Jones, M.B., Hedberg, R., Bradley, J., and F. Skokan, "OpenID Connect Relying Party Metadata Choices 1.0", 25 March 2026, <https://openid.net/specs/openid-connect-rp-metadata-choices-1_0.html>.

[RFC2119]

Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/rfc/rfc2119>.

[RFC3986]

Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <https://www.rfc-editor.org/rfc/rfc3986>.

[RFC6749]

Hardt, D., Ed., "The OAuth 2.0 Authorization Framework", RFC 6749, DOI 10.17487/RFC6749, October 2012, <https://www.rfc-editor.org/rfc/rfc6749>.

[RFC6819]

Lodderstedt, T., Ed., McGloin, M., and P. Hunt, "OAuth 2.0 Threat Model and Security Considerations", RFC 6819, DOI 10.17487/RFC6819, January 2013, <https://www.rfc-editor.org/rfc/rfc6819>.

[RFC6890]

Cotton, M., Vegoda, L., Bonica, R., Ed., and B. Haberman, "Special-Purpose IP Address Registries", BCP 153, RFC 6890, DOI 10.17487/RFC6890, April 2013, <https://www.rfc-editor.org/rfc/rfc6890>.

[RFC7523]

Jones, M., Campbell, B., and C. Mortimore, "JSON Web Token (JWT) Profile for OAuth 2.0 Client Authentication and Authorization Grants", RFC 7523, DOI 10.17487/RFC7523, May 2015, <https://www.rfc-editor.org/rfc/rfc7523>.

[RFC7591]

Richer, J., Ed., Jones, M., Bradley, J., Machulak, M., and P. Hunt, "OAuth 2.0 Dynamic Client Registration Protocol", RFC 7591, DOI 10.17487/RFC7591, July 2015, <https://www.rfc-editor.org/rfc/rfc7591>.

[RFC8174]

Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

[RFC8259]

Bray, T., Ed., "The JavaScript Object Notation (JSON) Data Interchange Format", STD 90, RFC 8259, DOI 10.17487/RFC8259, December 2017, <https://www.rfc-editor.org/rfc/rfc8259>.

[RFC8414]

Jones, M., Sakimura, N., and J. Bradley, "OAuth 2.0 Authorization Server Metadata", RFC 8414, DOI 10.17487/RFC8414, June 2018, <https://www.rfc-editor.org/rfc/rfc8414>.

[RFC8725]

Sheffer, Y., Hardt, D., and M. Jones, "JSON Web Token Best Current Practices", BCP 225, RFC 8725, DOI 10.17487/RFC8725, February 2020, <https://www.rfc-editor.org/rfc/rfc8725>.

[RFC9110]

Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, June 2022, <https://www.rfc-editor.org/rfc/rfc9110>.

[RFC9207]

Meyer zu Selhausen, K. and D. Fett, "OAuth 2.0 Authorization Server Issuer Identification", RFC 9207, DOI 10.17487/RFC9207, March 2022, <https://www.rfc-editor.org/rfc/rfc9207>.

[RFC9700]

Lodderstedt, T., Bradley, J., Labunets, A., and D. Fett, "Best Current Practice for OAuth 2.0 Security", BCP 240, RFC 9700, DOI 10.17487/RFC9700, January 2025, <https://www.rfc-editor.org/rfc/rfc9700>.

13.2. Informative References

[I-D.draft-ietf-oauth-attestation-based-client-auth]

Looker, T., Bastian, P., and C. Bormann, "OAuth 2.0 Attestation-Based Client Authentication", Work in Progress, Internet-Draft, draft-ietf-oauth-attestation-based-client-auth-12, 12 October 2026, <https://datatracker.ietf.org/doc/html/draft-ietf-oauth-attestation-based-client-auth-12>.

[I-D.draft-ietf-oauth-rfc7523bis]

Jones, M. B., Campbell, B., Mortimore, C., and F. Skokan, "Updates to OAuth 2.0 JSON Web Token (JWT) Client Authentication and Assertion-Based Authorization Grants", Work in Progress, Internet-Draft, draft-ietf-oauth-rfc7523bis-11, 28 April 2026, <https://datatracker.ietf.org/doc/html/draft-ietf-oauth-rfc7523bis-11>.

[I-D.draft-ietf-oauth-spiffe-client-auth]

Schwenkschuster, A., Kasselman, P., Rose, S., Thorgersen, S., and N. Cam-Winget, "OAuth SPIFFE Client Authentication", Work in Progress, Internet-Draft, draft-ietf-oauth-spiffe-client-auth-03, 2 November 2026, <https://datatracker.ietf.org/doc/html/draft-ietf-oauth-spiffe-client-auth-03>.

[IndieAuth]

Parecki, A., "IndieAuth", 12 February 2022, <https://indieauth.spec.indieweb.org/>.

[OpenID]

Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, "OpenID Connect Core 1.0", 15 December 2023, <https://openid.net/specs/openid-connect-core-1_0.html>.

[OpenID.Federation]

Hedberg, R., Jones, M.B., Solberg, A.Å., Bradley, J., De Marco, G., and V. Dzhuvinov, "OpenID Federation 1.1", 5 May 2026, <https://openid.net/specs/openid-federation-1_1-final.html>.

[OWASP.SSRF]

"OWASP SSRF Cheat Sheet", n.d., <https://cheatsheetseries.owasp.org/cheatsheets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet.html>.

[RFC9111]

Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Caching", STD 98, RFC 9111, DOI 10.17487/RFC9111, June 2022, <https://www.rfc-editor.org/rfc/rfc9111>.

[Solid-OIDC]

Coburn, A., elf Pavlik, and D. Zagidulin, "Solid-OIDC", 28 March 2022, <https://solidproject.org/TR/2022/oidc-20220328>.