chore: import upstream snapshot with attribution

docs_src/identity_assertion/tutorial001.py

@@ -0,0 +1,69 @@
+import time
+import uuid
+
+import httpx
+import jwt
+
+from mcp import Client
+from mcp.client.auth.extensions.identity_assertion import IdentityAssertionOAuthProvider
+from mcp.client.streamable_http import streamable_http_client
+from mcp.shared.auth import OAuthClientInformationFull, OAuthToken
+
+IDP_SIGNING_KEY = "the-enterprise-idp-signing-key"
+
+
+class InMemoryTokenStorage:
+    def __init__(self) -> None:
+        self.tokens: OAuthToken | None = None
+        self.client_info: OAuthClientInformationFull | None = None
+
+    async def get_tokens(self) -> OAuthToken | None:
+        return self.tokens
+
+    async def set_tokens(self, tokens: OAuthToken) -> None:
+        self.tokens = tokens
+
+    async def get_client_info(self) -> OAuthClientInformationFull | None:
+        return self.client_info
+
+    async def set_client_info(self, client_info: OAuthClientInformationFull) -> None:
+        self.client_info = client_info
+
+
+def idp_issue_id_jag(subject: str, audience: str, resource: str) -> str:
+    now = int(time.time())
+    claims = {
+        "iss": "https://idp.example.com",
+        "sub": subject,
+        "aud": audience,
+        "client_id": "finance-agent",
+        "resource": resource,
+        "scope": "notes:read",
+        "jti": str(uuid.uuid4()),
+        "iat": now,
+        "exp": now + 300,
+    }
+    return jwt.encode(claims, IDP_SIGNING_KEY, algorithm="HS256", headers={"typ": "oauth-id-jag+jwt"})
+
+
+async def fetch_id_jag(audience: str, resource: str) -> str:
+    return idp_issue_id_jag("alice@example.com", audience, resource)
+
+
+oauth = IdentityAssertionOAuthProvider(
+    server_url="http://localhost:8001/mcp",
+    storage=InMemoryTokenStorage(),
+    client_id="finance-agent",
+    client_secret="finance-agent-secret",
+    issuer="https://auth.example.com/",
+    assertion_provider=fetch_id_jag,
+    scope="notes:read",
+)
+
+
+async def main() -> None:
+    async with httpx.AsyncClient(auth=oauth, follow_redirects=True) as http_client:
+        transport = streamable_http_client("http://localhost:8001/mcp", http_client=http_client)
+        async with Client(transport) as client:
+            result = await client.list_tools()
+            print([tool.name for tool in result.tools])