feat(mcp): keep step-up grants when a refused refresh leads to a new authorization

packages/agents/src/mcp/client/do-oauth-client-provider.ts

@@ -89,6 +89,11 @@ function isExpired(createdAt: number): boolean {
 export type AgentsOAuthProvider = AgentMcpOAuthProvider;
 
 export class DurableObjectOAuthClientProvider implements AgentMcpOAuthProvider {
+  /**
+   * When a refresh is refused and the SDK starts a new authorization, also
+   * request the scope the dropped tokens held, so step-up grants survive.
+   */
+  readonly includePreviouslyGrantedScopes = true;
   private _authUrl_: string | undefined;
   private _serverId_: string | undefined;
   private _clientId_: string | undefined;

packages/agents/src/tests/mcp/mid-session-reauth.test.ts

@@ -336,6 +336,12 @@ describe("MCPClientManager mid-session re-authorization", () => {
       expect(error).toBeInstanceOf(MCPAuthorizationRequiredError);
       const reauth = error as MCPAuthorizationRequiredError;
       expect(reauth.authUrl).not.toBe(connectUrl);
+      // The server challenged with its base scope, but the new link must keep
+      // the write scope the user already granted, or the write tools fail
+      // again and the user is sent back through step-up.
+      expect(
+        new URL(reauth.authUrl).searchParams.get("scope")?.split(" ").sort()
+      ).toEqual(`${BASE_SCOPE} ${WRITE_SCOPE}`.split(" ").sort());
       expect(manager.mcpConnections[serverId].connectionState).toBe(
         "authenticating"
       );

pnpm-workspace.yaml

@@ -48,3 +48,10 @@ minimumReleaseAgeExclude:
   - "@opencode/*"
 overrides:
   "@earendil-works/pi-agent-core>@earendil-works/pi-ai": "~1.4.0"
+  # Preview of modelcontextprotocol/typescript-sdk#2448 (keep granted scopes on 401 re-authorization).
+  # The preview client depends on the preview core by URL, which needs blockExoticSubdeps off below.
+  "@modelcontextprotocol/client": "https://pkg.pr.new/@modelcontextprotocol/client@9f7c248"
+  "@modelcontextprotocol/core": "https://pkg.pr.new/@modelcontextprotocol/core@9f7c248"
+
+# Only for the typescript-sdk#2448 preview above; pnpm 10.x blocks URL subdependencies by default.
+blockExoticSubdeps: false