Pass issuer= in the remaining docstring examples and the story README

The PrivateKeyJWTOAuthProvider, static_assertion_provider and SignedJWTParameters examples now show the non-deprecated form, and the client-credentials story stops counting its config lines.

Author: maxisbey

examples/stories/oauth_client_credentials/README.md

@@ -33,8 +33,8 @@ the client and server side.
 - `client.py` `main` — opens with `async with Client(target, mode=mode) as
   client:` and that's the whole program. `target` is a transport that already
   carries the OAuth `httpx2.Auth`; the body never touches a token.
-- `client.py` `build_auth` — five lines of `ClientCredentialsOAuthProvider`
-  config is all the caller writes; the SDK does RFC 9728 PRM →
+- `client.py` `build_auth` — a few lines of `ClientCredentialsOAuthProvider`
+  config (credentials plus `issuer=`) is all the caller writes; the SDK does RFC 9728 PRM →
   RFC 8414 AS-metadata discovery and token exchange on the first 401.
 - `server.py` `token_endpoint` — the *entire* AS for this grant: validate
   HTTP-Basic `client_id:client_secret`, mint a token, return RFC 6749 JSON.

examples/stories/oauth_client_credentials/client.py

@@ -14,7 +14,7 @@
 
 
 def build_auth(_http: httpx2.AsyncClient) -> httpx2.Auth:
-    """The ``httpx2.Auth`` for the ``client_credentials`` grant — six lines of provider config.
+    """The ``httpx2.Auth`` for the ``client_credentials`` grant — a few lines of provider config.
 
     The SDK then handles 401 → RFC 9728 PRM → RFC 8414 AS-metadata discovery → token POST →
     Bearer attachment automatically. ``Client(url)`` has no ``auth=`` passthrough yet, so the

src/mcp/client/auth/extensions/client_credentials.py

@@ -180,6 +180,7 @@ def static_assertion_provider(token: str) -> Callable[[str], Awaitable[str]]:
             storage=my_token_storage,
             client_id="my-client-id",
             assertion_provider=static_assertion_provider(my_prebuilt_jwt),
+            issuer="https://auth.example.com",
         )
         ```
 
@@ -214,6 +215,7 @@ class SignedJWTParameters(BaseModel):
             storage=my_token_storage,
             client_id="my-client-id",
             assertion_provider=jwt_params.create_assertion_provider(),
+            issuer="https://auth.example.com",
         )
         ```
     """
@@ -279,6 +281,7 @@ async def get_workload_identity_token(audience: str) -> str:
             storage=my_token_storage,
             client_id="my-client-id",
             assertion_provider=get_workload_identity_token,
+            issuer="https://auth.example.com",
         )
         ```
 
@@ -292,6 +295,7 @@ async def get_workload_identity_token(audience: str) -> str:
             storage=my_token_storage,
             client_id="my-client-id",
             assertion_provider=static_assertion_provider(my_prebuilt_jwt),
+            issuer="https://auth.example.com",
         )
         ```
 
@@ -310,6 +314,7 @@ async def get_workload_identity_token(audience: str) -> str:
             storage=my_token_storage,
             client_id="my-client-id",
             assertion_provider=jwt_params.create_assertion_provider(),
+            issuer="https://auth.example.com",
         )
         ```
     """