diff --git a/src-node/claude-code-agent.js b/src-node/claude-code-agent.js
index cb96f66fd9..23e7ef827e 100644
--- a/src-node/claude-code-agent.js
+++ b/src-node/claude-code-agent.js
@@ -604,20 +604,6 @@ async function _getAISessionTitle(sessionId, projectPath) {
     }
 }
 
-/**
- * Resolve the user's globally installed Claude CLI, honouring the path
- * override configured in AI Settings. Kept as a local function so the SDK
- * path below reads the same as it always has; the search itself now lives
- * in cli-locator.js, shared with the other CLIs the panel can drive.
- * Pass `{ force: true }` to invalidate the cache after a spawn failure.
- * @return {Promise<string|null>} absolute path, or null when not found
- */
-function findGlobalClaudeCli(opts) {
-    return CliLocator.locateCli("claude", opts).then(function (result) {
-        return result.path;
-    });
-}
-
 // Brand names for the messages below. Not translatable and never shown
 // raw — the browser maps errorCode to a localized string; these only reach
 // logs and metrics.
@@ -826,7 +812,7 @@ exports.getCliSpawnProfile = async function (params) {
     if (!result.available) {
         return Object.assign({}, result, { command: null, args: [] });
     }
-    const profile = CliLocator.getSpawnProfile(result.path);
+    const profile = CliLocator.getSpawnProfile(result.path, result.source);
     return Object.assign({}, result, profile);
 };
 
@@ -2118,7 +2104,7 @@ async function _runQuery(requestId, prompt, projectPath, model, signal, locale,
                     // It also carries the live preview nudge as a fallback for
                     // Claude CLI versions that predate PostToolBatch: the batch
                     // hook below is the primary path, but we run the user's
-                    // global CLI (findGlobalClaudeCli) so we can't assume it.
+                    // whichever CLI the locator picked, so we can't assume it.
                     // Whichever fires first takes the hint; the other sees a
                     // cleared counter.
                     hooks: [
@@ -2214,10 +2200,13 @@ async function _runQuery(requestId, prompt, projectPath, model, signal, locale,
         };
     }
 
-    // Set Claude CLI path if found
-    const claudePath = await findGlobalClaudeCli();
-    if (claudePath) {
-        queryOptions.pathToClaudeCodeExecutable = claudePath;
+    // Set Claude CLI path if found. The env the binary's origin calls for
+    // rides along: the SDK spawns the same executable the CLI pane does, so
+    // the bundled copy must not try to auto-update here either.
+    const located = await CliLocator.locateCli("claude");
+    if (located.path) {
+        queryOptions.pathToClaudeCodeExecutable = located.path;
+        Object.assign(queryOptions.env, CliLocator.getSourceEnv(located.source));
     }
 
     if (model) {
diff --git a/src-node/cli-locator.js b/src-node/cli-locator.js
index a1b1fe19e7..088912d1f5 100644
--- a/src-node/cli-locator.js
+++ b/src-node/cli-locator.js
@@ -780,6 +780,26 @@ function findDownloader() {
     return null;
 }
 
+/**
+ * Env a CLI needs on top of PATH, decided by where the binary came from.
+ *
+ * The bundled Claude Code ships inside Phoenix and is replaced when Phoenix
+ * updates, so its own auto-updater has nothing useful to do — and it cannot
+ * do it anyway: it resolves the npm prefix of whatever install it thinks it
+ * is and tries to write there, which is a directory Phoenix neither owns nor
+ * should touch. It fails every launch and says so in red across the CLI pane
+ * ("Auto-update failed: no write permission to npm prefix"). Turning the
+ * updater off is the supported way out (Anthropic set the same var for their
+ * own managed runs). A CLI the *user* installed keeps its updater: that copy
+ * is theirs to keep current, and it is how their version eventually
+ * overtakes the bundled one.
+ * @param {?string} source - `source` from locateCli(): "bundled" when ours
+ * @return {Object}
+ */
+function _cliSourceEnv(source) {
+    return source === "bundled" ? { DISABLE_AUTOUPDATER: "1" } : {};
+}
+
 /**
  * How to hand a resolved binary to node-pty.
  *
@@ -789,12 +809,14 @@ function findDownloader() {
  * to spawn, so every terminal caller must resolve through here rather than
  * using the raw path.
  * `env` carries the same PATH used for probes so child tools such as npm
- * remain available in the terminal. Callers must forward it to the PTY.
+ * remain available in the terminal, plus whatever `source` implies. Callers
+ * must forward it to the PTY.
  * @param {string} cliPath - Resolved CLI path
+ * @param {?string} [source] - `source` from locateCli(), for the env above
  * @return {{command: string, args: Array<string>, env: Object}}
  */
-function getSpawnProfile(cliPath) {
-    const env = _cliPathEnv(cliPath, process.env);
+function getSpawnProfile(cliPath, source) {
+    const env = Object.assign(_cliPathEnv(cliPath, process.env), _cliSourceEnv(source));
     if (isWindows && /\.(cmd|bat)$/i.test(cliPath || "")) {
         return { command: process.env.COMSPEC || "cmd.exe", args: ["/c", cliPath], env };
     }
@@ -809,6 +831,7 @@ exports.locateCli = locateCli;
 exports.validateCliPath = validateCliPath;
 exports.findDownloader = findDownloader;
 exports.getSpawnProfile = getSpawnProfile;
+exports.getSourceEnv = _cliSourceEnv;
 exports.compareVersions = compareVersions;
 exports.setBundledRoot = setBundledRoot;
 exports.setOverrides = setOverrides;
diff --git a/src-node/test/test-cli-locator.js b/src-node/test/test-cli-locator.js
index ec46cc0eb5..1dd8a4a3d9 100644
--- a/src-node/test/test-cli-locator.js
+++ b/src-node/test/test-cli-locator.js
@@ -73,12 +73,12 @@ function _runProcess(command, args, env) {
 
 /**
  * Return a launch profile and the input environment after the locator runs.
- * @param {Object} params - Simulated platform, env, and cliPath
+ * @param {Object} params - Simulated platform, env, cliPath, and locate source
  * @return {Promise<Object>} Profile and environment for Jasmine assertions
  */
-async function getSpawnProfile({platform, env, cliPath}) {
+async function getSpawnProfile({platform, env, cliPath, source}) {
     const locator = _loadLocator(platform, env);
-    return { profile: locator.getSpawnProfile(cliPath), env };
+    return { profile: locator.getSpawnProfile(cliPath, source), env };
 }
 
 /**
diff --git a/test/spec/CLILocator-test.js b/test/spec/CLILocator-test.js
index 7068b66aca..9b3aea2525 100644
--- a/test/spec/CLILocator-test.js
+++ b/test/spec/CLILocator-test.js
@@ -35,6 +35,23 @@ define(function (require, exports, module) {
             });
         });
 
+        it("should silence the auto-updater only for the bundled Claude Code", async function () {
+            const args = {
+                platform: "linux", env: { PATH: "/usr/bin" }, cliPath: "/opt/node/bin/claude"
+            };
+            // Ours: it cannot write to the npm prefix it thinks it owns, and
+            // says so in red on every launch. Phoenix updates this copy.
+            const bundled = await nodeConnector.execPeer("getSpawnProfile",
+                Object.assign({ source: "bundled" }, args));
+            expect(bundled.profile.env.DISABLE_AUTOUPDATER).toBe("1");
+            // Theirs: left alone, so their own install can still catch up.
+            for (const source of ["native", "fallback", "override", null]) {
+                const own = await nodeConnector.execPeer("getSpawnProfile",
+                    Object.assign({ source }, args));
+                expect(Object.keys(own.profile.env)).withContext(source).toEqual(["PATH"]);
+            }
+        });
+
         it("macOS: should make Homebrew bin available to the updater", async function () {
             const result = await nodeConnector.execPeer("getSpawnProfile", {
                 platform: "darwin",