Refuse conflicting Claude identity during startup

packages/acp/tests/adapter-protocol.test.ts

@@ -524,6 +524,39 @@ describe("Tier EA — the embedded adapters' prompt-response metadata", () => {
     });
   }
 
+  it("HC Claude refuses conflicting confirmation during optional setup", function* () {
+    let root: string | undefined;
+    yield* ensure(function* () {
+      if (root !== undefined) {
+        yield* rm(root, { recursive: true, force: true });
+      }
+    });
+    root = yield* until(mkdtemp(join(tmpdir(), "xmd startup conflict ")));
+    const adapter = yield* useAdapter("claude", {
+      ...CLAUDE_ENV,
+      CLAUDE_CONFIG_DIR: root,
+      ANTHROPIC_MODEL: "",
+      FAKE_CLAUDE_CONFIRMATION: "conflicting",
+      FAKE_CLAUDE_CONFLICT_AT: "context-request",
+    });
+    yield* initialize(adapter);
+    let failure;
+    try {
+      yield* adapter.request("session/resume", {
+        sessionId: "11111111-1111-4111-8111-111111111111",
+        cwd: root,
+        mcpServers: [],
+      });
+    } catch (error) {
+      failure = String(error);
+    }
+    const log = yield* readTextFile(adapter.log);
+    expect(log).toContain('"event":"conflict-at-context-request"');
+    expect(failure).toContain("Claude SessionStart identity confirmation failed");
+    expect(acceptances(adapter)).toEqual([]);
+    expect(log).not.toContain('"type":"user"');
+  });
+
   it("HC Claude cancellation joins the held startup Query with no late response", function* () {
     let adapter: Adapter | undefined;
     let answered = false;

packages/acp/tests/fixtures/fake-claude-cli.cjs

@@ -92,7 +92,7 @@ function confirm() {
     uuid: crypto.randomUUID(),
     session_id: confirmation === "mismatch" ? "other-conversation" : SESSION,
   });
-  if (confirmation === "conflicting") {
+  if (confirmation === "conflicting" && process.env.FAKE_CLAUDE_CONFLICT_AT !== "context-request") {
     emit({
       type: "system",
       subtype: "hook_response",
@@ -142,6 +142,29 @@ process.stdin.on("data", (chunk) => {
     // The SDK opens with a control handshake and will not send a turn until it
     // is answered.
     if (message.type === "control_request") {
+      if (
+        confirmation === "conflicting" &&
+        process.env.FAKE_CLAUDE_CONFLICT_AT === "context-request" &&
+        message.request?.subtype === "get_context_usage"
+      ) {
+        log({ event: "conflict-at-context-request" });
+        emit({
+          type: "system",
+          subtype: "hook_response",
+          hook_id: "internal",
+          hook_name: "opaque",
+          hook_event: "SessionStart",
+          stdout: "",
+          stderr: "",
+          output: "",
+          exit_code: 0,
+          outcome: "success",
+          uuid: crypto.randomUUID(),
+          session_id: "other-conversation",
+        });
+        // Only Query failure releases this lookup, so setup cannot outrun the contradiction.
+        continue;
+      }
       emit({
         type: "control_response",
         response: {

packages/acp/vendor/adapters/MANIFEST.json

@@ -32,14 +32,14 @@
       "tarball": "claude/agentclientprotocol-claude-agent-acp-0.70.0.tgz",
       "repository": "https://github.com/agentclientprotocol/claude-agent-acp",
       "upstreamBase": "8710ce1cbccf562cb04b4bcc30e053e960aee05f",
-      "patchedCommit": "54df80cbb41f2aa56195fd56b4dc2a88295049af",
+      "patchedCommit": "bea799c86d16ed2b1bf1cfe8d7fd6e22e6525b56",
       "pullRequest": "https://github.com/agentclientprotocol/claude-agent-acp/pull/1047",
       "buildCommand": "npm run build && npm pack",
       "license": "Apache-2.0",
       "contract": "_meta.claudeCode.assistantMessageUuid",
       "materializationContract": "session_info_update _meta[executablemd.session-materialization/v1]",
-      "byteLength": 195701,
-      "sha256": "a62d36d02a3e3e5cc896d5467ad8026a59e7d5e5a1940068aebae5f03f469488",
+      "byteLength": 195823,
+      "sha256": "6490fb5dccf0273720587bf0a2e2d5940d4afb73119b82011e9cedf6ffe9be8f",
       "files": [
         "package/LICENSE",
         "package/README.md",

packages/acp/vendor/adapters/PROVENANCE.md

@@ -71,13 +71,16 @@ owned SDK Query supplies a successful SessionStart lifecycle response with that
 exact `session_id`. One fixed no-op command hook, using the adapter's own Node
 runtime, is composed into settings before startup or resume. Deliberate settings
 and hooks survive; disabled, absent, failed, conflicting or mismatched
-confirmation refuses. One owned reader buffers early unrelated messages and
+confirmation refuses. The reader records identity refusal before closing its SDK
+iterator, whose cleanup can release pending setup lookups. Session publication
+rechecks reader failure and disposal after optional SDK setup, before registering
+or answering success. One owned reader buffers early unrelated messages and
 retains the explicit acceptance and exact completed-prompt checkpoint handling.
 Fresh confirmation stays provisional until acceptance and the asserting save.
 Native Claude allocation remains client-allocated, independently of metadata.
 
 The Claude source revision recorded in MANIFEST.json extends the retained patch
-at `beba04dc177ba09bcc9fa10b56e9ded7f219513e`; its local source patch and build
+at `54df80cbb41f2aa56195fd56b4dc2a88295049af`; its local source patch and build
 receipt are supplied with the implementation evidence. The pin records source
 identity, not an unperformed independent review.