AuthorizationServerMetadataClient

Definition

Assembly: Microsoft.OData.Mcp.Authentication.dll Namespace: Microsoft.OData.Mcp.Authentication.Outbound Inheritance: System.Object

Syntax

Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadataClient

Summary

Discovers an RFC 8414 authorization server metadata document (or its OpenID Connect discovery document counterpart) over the handler-free "OAuth" named HttpClient, probing the well-known candidates for a base URI in the order that prefers a Microsoft identity platform v2 document over its v1 counterpart.

Remarks

A new "OAuth" client is requested from IHttpClientFactory on every call rather than cached, matching the “Two named HttpClients” table in specs/v3/AUTHENTICATION.md. Per AUTH-14, an Entra-style authorization server publishes both a v1 (OpenID Connect only) and a v2 (RFC 8414 and OpenID Connect) document at the same base URI; Uri) orders the v2 candidates first so discovery never selects the v1 issuer when a v2 one is available. Response bodies are never logged.

Examples

var client = new AuthorizationServerMetadataClient(httpClientFactory, logger);
var metadata = await client.DiscoverAsync(new Uri("https://login.microsoftonline.com/common"), cancellationToken);
if (metadata is not null)
{
    // metadata.TokenEndpoint is guaranteed non-null and absolute.
}

Constructors

.ctor

Initializes a new instance of the AuthorizationServerMetadataClient class.

Syntax

public AuthorizationServerMetadataClient(System.Net.Http.IHttpClientFactory httpClientFactory, Microsoft.Extensions.Logging.ILogger<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadataClient> logger)

Parameters

Name	Type	Description
`httpClientFactory`	`System.Net.Http.IHttpClientFactory`	The factory used to create the `"OAuth"` named client per call.
`logger`	`Microsoft.Extensions.Logging.ILogger<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadataClient>`	The logger this instance records non-fatal well-known outcomes and probe attempts to.

Exceptions

Exception	Description
`ArgumentNullException`	Thrown when httpClientFactory or logger is `null`.

.ctor Inherited

Inherited from object

Syntax

public Object()

Methods

CandidateDocuments

Builds the well-known authorization server metadata candidates for a base URI, in probe order.

Syntax

public static System.Collections.Generic.IReadOnlyList<System.Uri> CandidateDocuments(System.Uri baseUri)

Parameters

Name	Type	Description
`baseUri`	`System.Uri`	The absolute authorization server base URI, such as an issuer or an authorization endpoint’s origin and path.

Returns

Type: System.Collections.Generic.IReadOnlyList<System.Uri> Five candidates when baseUri carries a path beyond /: the versioned (v2) RFC 8414 document, the versioned OpenID Connect document, the unversioned RFC 8414 document, the RFC 8414 §3.1 path-prefixed document, and the unversioned OpenID Connect document, in that order. The path-prefixed candidate is omitted, leaving four candidates, when baseUri has no path beyond /.

Exceptions

Exception	Description
`ArgumentNullException`	Thrown when baseUri is `null`.
`ArgumentException`	Thrown when baseUri is not an absolute URI.

Remarks

A trailing / on baseUri is trimmed before any suffix is appended, so no candidate carries a doubled path separator. The versioned candidates are listed first so that an Entra-style authorization server, which publishes a v1 (OpenID Connect only) document at the unversioned base and a v2 (RFC 8414 and OpenID Connect) document under /v2.0, is discovered through its v2 issuer.

DiscoverAsync

Probes Uri) in order and returns the first candidate that resolves to a usable metadata document.

Syntax

public System.Threading.Tasks.Task<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadata> DiscoverAsync(System.Uri baseUri, System.Threading.CancellationToken cancellationToken)

Parameters

Name	Type	Description
`baseUri`	`System.Uri`	The absolute authorization server base URI to discover metadata for.
`cancellationToken`	`System.Threading.CancellationToken`	The token that cancels the request.

Returns

Type: System.Threading.Tasks.Task<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadata?> The first candidate’s parsed document, or null when every candidate is non-fatally unusable (missing, unparseable, or lacking a token_endpoint).

Exceptions

Exception	Description
`ArgumentNullException`	Thrown when baseUri is `null`.
`ArgumentException`	Thrown when baseUri is not an absolute URI.
`OutboundDiscoveryException`	Thrown when a probe times out, fails at the transport, or returns a 5xx status, after one retry.

Examples

var metadata = await client.DiscoverAsync(new Uri("https://login.microsoftonline.com/common"), cancellationToken);

Remarks

Every probe is attempted over http only when its host is loopback; discovery stops at the first candidate with a token_endpoint, so a later candidate (such as the legacy v1 document) is never requested once an earlier one has already succeeded.

Equals Inherited Virtual

Inherited from object

Syntax

public virtual bool Equals(object obj)

Parameters

Name	Type	Description
`obj`	`object?`	-

Returns

Type: bool

Equals Inherited

Inherited from object

Syntax

public static bool Equals(object objA, object objB)

Parameters

Name	Type	Description
`objA`	`object?`	-
`objB`	`object?`	-

Returns

Type: bool

GetHashCode Inherited Virtual

Inherited from object

Syntax

public virtual int GetHashCode()

Returns

Type: int

GetType Inherited

Inherited from object

Syntax

public System.Type GetType()

Returns

Type: System.Type

MemberwiseClone Inherited

Inherited from object

Syntax

protected internal object MemberwiseClone()

Returns

Type: object

ReferenceEquals Inherited

Inherited from object

Syntax

public static bool ReferenceEquals(object objA, object objB)

Parameters

Name	Type	Description
`objA`	`object?`	-
`objB`	`object?`	-

Returns

Type: bool

ToString Inherited Virtual

Inherited from object

Syntax

public virtual string ToString()

Returns

Type: string?

TryGetAsync

Attempts to fetch and parse the authorization server metadata document at a well-known URL.

Syntax

public System.Threading.Tasks.Task<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadata> TryGetAsync(System.Uri url, System.Threading.CancellationToken cancellationToken)

Parameters

Name	Type	Description
`url`	`System.Uri`	The absolute authorization server metadata URL.
`cancellationToken`	`System.Threading.CancellationToken`	The token that cancels the request.

Returns

Type: System.Threading.Tasks.Task<Microsoft.OData.Mcp.Authentication.Outbound.AuthorizationServerMetadata?> The parsed document on a 200 response with a well-formed body carrying an absolute token_endpoint; otherwise null after a 401, 403, 404, unparseable body, a document without a usable token_endpoint, or any other non-retryable non-success status.

Exceptions

Exception	Description
`ArgumentNullException`	Thrown when url is `null`.
`ArgumentException`	Thrown when url is not an absolute URI, or is an `http` URI whose host is not loopback.
`OutboundDiscoveryException`	Thrown when the request times out, fails at the transport, or returns a 5xx status, after one retry.

Examples

var metadata = await client.TryGetAsync(new Uri("https://login.microsoftonline.com/common/v2.0/.well-known/oauth-authorization-server"), cancellationToken);

​Definition

​Syntax

​Summary

​Remarks

​Examples

​Constructors

​ .ctor

​Syntax

​Parameters

​Exceptions

​ .ctor Inherited

​Syntax

​Methods

​ CandidateDocuments

​Syntax

​Parameters

​Returns

​Exceptions

​Remarks

​ DiscoverAsync

​Syntax

​Parameters

​Returns

​Exceptions

​Examples

​Remarks

​ Equals Inherited Virtual

​Syntax

​Parameters

​Returns

​ Equals Inherited

​Syntax

​Parameters

​Returns

​ GetHashCode Inherited Virtual

​Syntax

​Returns

​ GetType Inherited

​Syntax

​Returns

​ MemberwiseClone Inherited

​Syntax

​Returns

​ ReferenceEquals Inherited

​Syntax

​Parameters

​Returns

​ ToString Inherited Virtual

​Syntax

​Returns

​ TryGetAsync

​Syntax

​Parameters

​Returns

​Exceptions

​Examples

Definition

Syntax

Summary

Remarks

Examples

Constructors

.ctor

Syntax

Parameters

Exceptions

.ctor Inherited

Syntax

Methods

CandidateDocuments

Syntax

Parameters

Returns

Exceptions

Remarks

DiscoverAsync

Syntax

Parameters

Returns

Exceptions

Examples

Remarks

Equals Inherited Virtual

Syntax

Parameters

Returns

Equals Inherited

Syntax

Parameters

Returns

GetHashCode Inherited Virtual

Syntax

Returns

GetType Inherited

Syntax

Returns

MemberwiseClone Inherited

Syntax

Returns

ReferenceEquals Inherited

Syntax

Parameters

Returns

ToString Inherited Virtual

Syntax

Returns

TryGetAsync

Syntax

Parameters

Returns

Exceptions

Examples