diff --git a/scripts/hooks/mcp-health-check.js b/scripts/hooks/mcp-health-check.js
index 843a6ec04..6003033c3 100644
--- a/scripts/hooks/mcp-health-check.js
+++ b/scripts/hooks/mcp-health-check.js
@@ -47,11 +47,29 @@ function envNumber(name, fallback) {
   return Number.isFinite(value) && value >= 0 ? value : fallback;
 }
 
+// Resolve the Claude profile directory the same way everywhere.
+//
+// Duplicated rather than imported on purpose: hooks ship in managed installs
+// that carry top-level `scripts/` without `scripts/lib/` (see #3259), so a
+// require into lib/ would make the hook unloadable there. `~` is expanded the
+// way `scripts/lib/agent-data-home.js` expands it, so a profile written as
+// `~/.claude-work` resolves to one place rather than two.
+function claudeConfigDir() {
+  const configured = process.env.CLAUDE_CONFIG_DIR;
+  const trimmed = configured ? String(configured).trim() : '';
+  if (!trimmed) return path.join(os.homedir(), '.claude');
+  if (trimmed.startsWith('~')) {
+    const remainder = trimmed.slice(1).replace(/^[/\\]+/, '');
+    return remainder ? path.join(os.homedir(), remainder) : os.homedir();
+  }
+  return path.resolve(trimmed);
+}
+
 function stateFilePath() {
   if (process.env.ECC_MCP_HEALTH_STATE_PATH) {
     return path.resolve(process.env.ECC_MCP_HEALTH_STATE_PATH);
   }
-  return path.join(os.homedir(), '.claude', 'mcp-health-cache.json');
+  return path.join(claudeConfigDir(), 'mcp-health-cache.json');
 }
 
 function configPaths() {
diff --git a/scripts/hooks/plan-canvas-pending.js b/scripts/hooks/plan-canvas-pending.js
index 9ba2a9207..b9b7dee4b 100644
--- a/scripts/hooks/plan-canvas-pending.js
+++ b/scripts/hooks/plan-canvas-pending.js
@@ -34,10 +34,28 @@ const path = require('path');
 const SERVER_TIMEOUT_MS = 1000;
 const MAX_ITEMS_REPORTED = 20;
 
+// Resolve the Claude profile directory the same way everywhere.
+//
+// Duplicated rather than imported on purpose: hooks ship in managed installs
+// that carry top-level `scripts/` without `scripts/lib/` (see #3259), so a
+// require into lib/ would make the hook unloadable there. `~` is expanded the
+// way `scripts/lib/agent-data-home.js` expands it, so a profile written as
+// `~/.claude-work` resolves to one place rather than two.
+function claudeConfigDir() {
+  const configured = process.env.CLAUDE_CONFIG_DIR;
+  const trimmed = configured ? String(configured).trim() : '';
+  if (!trimmed) return path.join(os.homedir(), '.claude');
+  if (trimmed.startsWith('~')) {
+    const remainder = trimmed.slice(1).replace(/^[/\\]+/, '');
+    return remainder ? path.join(os.homedir(), remainder) : os.homedir();
+  }
+  return path.resolve(trimmed);
+}
+
 function stateDir() {
   const override = process.env.ECC_PLAN_CANVAS_STATE_DIR;
   if (override && override.trim()) return path.resolve(override.trim());
-  return path.join(os.homedir(), '.claude', 'plan-canvas');
+  return path.join(claudeConfigDir(), 'plan-canvas');
 }
 
 function readState() {
diff --git a/scripts/hooks/plan-canvas-sessions.js b/scripts/hooks/plan-canvas-sessions.js
index 4e0799f87..b2e4a1574 100644
--- a/scripts/hooks/plan-canvas-sessions.js
+++ b/scripts/hooks/plan-canvas-sessions.js
@@ -19,10 +19,28 @@ const fs = require('fs');
 const path = require('path');
 const os = require('os');
 
+// Resolve the Claude profile directory the same way everywhere.
+//
+// Duplicated rather than imported on purpose: hooks ship in managed installs
+// that carry top-level `scripts/` without `scripts/lib/` (see #3259), so a
+// require into lib/ would make the hook unloadable there. `~` is expanded the
+// way `scripts/lib/agent-data-home.js` expands it, so a profile written as
+// `~/.claude-work` resolves to one place rather than two.
+function claudeConfigDir() {
+  const configured = process.env.CLAUDE_CONFIG_DIR;
+  const trimmed = configured ? String(configured).trim() : '';
+  if (!trimmed) return path.join(os.homedir(), '.claude');
+  if (trimmed.startsWith('~')) {
+    const remainder = trimmed.slice(1).replace(/^[/\\]+/, '');
+    return remainder ? path.join(os.homedir(), remainder) : os.homedir();
+  }
+  return path.resolve(trimmed);
+}
+
 function stateDir() {
   const override = process.env.ECC_PLAN_CANVAS_STATE_DIR;
   if (override && override.trim()) return path.resolve(override.trim());
-  return path.join(os.homedir(), '.claude', 'plan-canvas');
+  return path.join(claudeConfigDir(), 'plan-canvas');
 }
 
 function openSessions() {
diff --git a/scripts/hooks/post-bash-command-log.js b/scripts/hooks/post-bash-command-log.js
index bdea239df..c57579d49 100644
--- a/scripts/hooks/post-bash-command-log.js
+++ b/scripts/hooks/post-bash-command-log.js
@@ -38,6 +38,24 @@ function appendLine(filePath, line) {
   fs.appendFileSync(filePath, `${line}\n`, 'utf8');
 }
 
+// Resolve the Claude profile directory the same way everywhere.
+//
+// Duplicated rather than imported on purpose: hooks ship in managed installs
+// that carry top-level `scripts/` without `scripts/lib/` (see #3259), so a
+// require into lib/ would make the hook unloadable there. `~` is expanded the
+// way `scripts/lib/agent-data-home.js` expands it, so a profile written as
+// `~/.claude-work` resolves to one place rather than two.
+function claudeConfigDir() {
+  const configured = process.env.CLAUDE_CONFIG_DIR;
+  const trimmed = configured ? String(configured).trim() : '';
+  if (!trimmed) return path.join(os.homedir(), '.claude');
+  if (trimmed.startsWith('~')) {
+    const remainder = trimmed.slice(1).replace(/^[/\\]+/, '');
+    return remainder ? path.join(os.homedir(), remainder) : os.homedir();
+  }
+  return path.resolve(trimmed);
+}
+
 function run(rawInput, mode = 'audit') {
   const config = MODE_CONFIG[mode];
 
@@ -45,7 +63,7 @@ function run(rawInput, mode = 'audit') {
     if (config) {
       const input = String(rawInput || '').trim() ? JSON.parse(String(rawInput)) : {};
       const command = sanitizeCommand(input.tool_input?.command || '?');
-      appendLine(path.join(os.homedir(), '.claude', config.fileName), config.format(command));
+      appendLine(path.join(claudeConfigDir(), config.fileName), config.format(command));
     }
   } catch {
     // Logging must never block the calling hook.
diff --git a/scripts/lib/agent-data-home.js b/scripts/lib/agent-data-home.js
index 98cd0a84b..48d9b4294 100644
--- a/scripts/lib/agent-data-home.js
+++ b/scripts/lib/agent-data-home.js
@@ -17,6 +17,7 @@ const path = require('path');
 const { assertWithinTrustedRoot } = require('./path-safety');
 
 const AGENT_DATA_HOME_ENV = 'ECC_AGENT_DATA_HOME';
+const CLAUDE_CONFIG_DIR_ENV = 'CLAUDE_CONFIG_DIR';
 const DEFAULT_CLAUDE_DIR_NAME = '.claude';
 const DEFAULT_CURSOR_ECC_DIR_SEGMENTS = ['.cursor', 'ecc'];
 const PROJECT_CONFIG_RELATIVE = path.join('.cursor', 'ecc-agent-data.json');
@@ -92,7 +93,9 @@ function getDefaultCursorAgentDataHome() {
 }
 
 function getDefaultClaudeAgentDataHome() {
-  const fromClaudeConfigDir = expandHomePath(process.env.CLAUDE_CONFIG_DIR);
+  // Launcher-owned CLAUDE_CONFIG_DIR moves the Claude trusted root with its
+  // profile. Project-provided paths must still remain inside that root.
+  const fromClaudeConfigDir = expandHomePath(process.env[CLAUDE_CONFIG_DIR_ENV]);
   if (fromClaudeConfigDir) return fromClaudeConfigDir;
   return path.join(getHomeDirFromEnv(), DEFAULT_CLAUDE_DIR_NAME);
 }
@@ -232,6 +235,7 @@ function getCursorSessionEnvPayload(options = {}) {
 
 module.exports = {
   AGENT_DATA_HOME_ENV,
+  CLAUDE_CONFIG_DIR_ENV,
   DEFAULT_CLAUDE_DIR_NAME,
   DEFAULT_CURSOR_ECC_DIR_SEGMENTS,
   PROJECT_CONFIG_RELATIVE,
diff --git a/scripts/lib/plan-canvas/sessions.js b/scripts/lib/plan-canvas/sessions.js
index 799cf4b36..cd254600d 100644
--- a/scripts/lib/plan-canvas/sessions.js
+++ b/scripts/lib/plan-canvas/sessions.js
@@ -16,10 +16,26 @@ const path = require('path');
 const FEEDBACK_KINDS = new Set(['chat', 'annotation', 'verdict']);
 const VERDICTS = new Set(['approve', 'request-changes']);
 
+// The producer and the SessionStart/Stop hooks must land on one directory. The
+// hooks resolve CLAUDE_CONFIG_DIR (they cannot require this file: managed
+// installs ship scripts/ without scripts/lib/, see #3259), so writing to
+// ~/.claude here regardless would hide queued feedback from them whenever a
+// session runs under a second profile.
+function resolveClaudeConfigDir(env = process.env) {
+  const configured = env.CLAUDE_CONFIG_DIR;
+  const trimmed = configured ? String(configured).trim() : '';
+  if (!trimmed) return path.join(os.homedir(), '.claude');
+  if (trimmed.startsWith('~')) {
+    const remainder = trimmed.slice(1).replace(/^[/\\]+/, '');
+    return remainder ? path.join(os.homedir(), remainder) : os.homedir();
+  }
+  return path.resolve(trimmed);
+}
+
 function resolveStateDir(env = process.env) {
   const override = env.ECC_PLAN_CANVAS_STATE_DIR;
   if (override && String(override).trim()) return path.resolve(String(override).trim());
-  return path.join(os.homedir(), '.claude', 'plan-canvas');
+  return path.join(resolveClaudeConfigDir(env), 'plan-canvas');
 }
 
 // Canonicalize so `./plan.md`, symlinks, and absolute paths all land on the
diff --git a/tests/hooks/claude-config-dir-routing.test.js b/tests/hooks/claude-config-dir-routing.test.js
new file mode 100644
index 000000000..d82f41204
--- /dev/null
+++ b/tests/hooks/claude-config-dir-routing.test.js
@@ -0,0 +1,282 @@
+/**
+ * Tests that the hooks route profile state through CLAUDE_CONFIG_DIR
+ *
+ * Run with: node tests/hooks/claude-config-dir-routing.test.js
+ *
+ * These spawn the hooks rather than calling the shared resolver. The four hooks
+ * below cannot require scripts/lib/agent-data-home.js: managed installs ship a
+ * top-level scripts/ without scripts/lib/ (#3259), so each carries its own copy
+ * of the resolver. A resolver test therefore cannot show where a hook writes.
+ */
+
+const assert = require('assert');
+const path = require('path');
+const fs = require('fs');
+const os = require('os');
+const { spawnSync } = require('child_process');
+
+const hooksDir = path.join(__dirname, '..', '..', 'scripts', 'hooks');
+const libSessions = path.join(__dirname, '..', '..', 'scripts', 'lib', 'plan-canvas', 'sessions.js');
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  ✓ ${name}`);
+    return true;
+  } catch (err) {
+    console.log(`  ✗ ${name}`);
+    console.log(`    Error: ${err.message}`);
+    return false;
+  }
+}
+
+function makeTempDir() {
+  return fs.realpathSync(fs.mkdtempSync(path.join(os.tmpdir(), 'config-dir-routing-')));
+}
+
+/**
+ * A profile that is not the home directory, so a hook that ignored
+ * CLAUDE_CONFIG_DIR would write somewhere this returns.
+ */
+function makeProfile() {
+  const root = makeTempDir();
+  return {
+    home: path.join(root, 'home'),
+    profile: path.join(root, 'profile', '.claude-work'),
+  };
+}
+
+// No ECC_* override is passed anywhere here: an override would route the hook
+// before it reached the CLAUDE_CONFIG_DIR fallback under test.
+function runHook(hookFile, { profile, home, stdin = '{}', args = [], env = {} }) {
+  fs.mkdirSync(home, { recursive: true });
+  return spawnSync('node', [path.join(hooksDir, hookFile), ...args], {
+    input: stdin,
+    encoding: 'utf8',
+    env: {
+      ...process.env,
+      HOME: home,
+      USERPROFILE: home,
+      CLAUDE_CONFIG_DIR: profile,
+      ECC_PLAN_CANVAS_STATE_DIR: undefined,
+      ECC_MCP_HEALTH_STATE_PATH: undefined,
+      ...env,
+    },
+  });
+}
+
+/**
+ * plan-canvas-pending.js exports run() and is required by the lifecycle hook
+ * bootstrap rather than spawned, so it is driven here in a child process. The
+ * child is what makes CLAUDE_CONFIG_DIR meaningful: requiring it in-process,
+ * the way tests/hooks/plan-canvas-pending-hook.test.js does with
+ * ECC_PLAN_CANVAS_STATE_DIR, cannot reach the fallback under test.
+ */
+function runPendingHook({ profile, home, payload }) {
+  fs.mkdirSync(home, { recursive: true });
+  const result = spawnSync('node', ['-e', `
+    require(${JSON.stringify(path.join(hooksDir, 'plan-canvas-pending.js'))})
+      .run(${JSON.stringify(JSON.stringify(payload))})
+      .then(out => process.stdout.write(out.stdout));
+  `], {
+    encoding: 'utf8',
+    env: {
+      ...process.env,
+      HOME: home,
+      USERPROFILE: home,
+      CLAUDE_CONFIG_DIR: profile,
+      ECC_PLAN_CANVAS_STATE_DIR: undefined,
+    },
+  });
+  assert.strictEqual(result.status, 0, `pending hook failed: ${result.stderr}`);
+  return result.stdout;
+}
+
+function writeSessions(stateDir, sessions) {
+  fs.mkdirSync(stateDir, { recursive: true });
+  fs.writeFileSync(path.join(stateDir, 'sessions.json'), JSON.stringify({ sessions }, null, 2));
+}
+
+function runTests() {
+  console.log('\n🧪 Testing CLAUDE_CONFIG_DIR routing in hooks\n');
+  let passed = 0;
+  let failed = 0;
+  const record = ok => { if (ok) passed++; else failed++; };
+
+  console.log('post-bash-command-log.js');
+
+  record(test('writes the audit log under CLAUDE_CONFIG_DIR', () => {
+    const { home, profile } = makeProfile();
+    runHook('post-bash-command-log.js', {
+      home,
+      profile,
+      args: ['audit'],
+      stdin: JSON.stringify({ tool_name: 'Bash', tool_input: { command: 'echo routed' } }),
+    });
+    const log = path.join(profile, 'bash-commands.log');
+    assert.ok(fs.existsSync(log), `expected ${log} to exist`);
+    assert.match(fs.readFileSync(log, 'utf8'), /echo routed/);
+    assert.ok(
+      !fs.existsSync(path.join(home, '.claude', 'bash-commands.log')),
+      'the log must not also land in ~/.claude'
+    );
+  }));
+
+  record(test('writes the cost log under CLAUDE_CONFIG_DIR', () => {
+    const { home, profile } = makeProfile();
+    runHook('post-bash-command-log.js', {
+      home,
+      profile,
+      args: ['cost'],
+      stdin: JSON.stringify({ tool_name: 'Bash', tool_input: { command: 'echo costed' } }),
+    });
+    assert.match(fs.readFileSync(path.join(profile, 'cost-tracker.log'), 'utf8'), /echo costed/);
+  }));
+
+  record(test('falls back to ~/.claude when CLAUDE_CONFIG_DIR is unset', () => {
+    const { home } = makeProfile();
+    fs.mkdirSync(home, { recursive: true });
+    spawnSync('node', [path.join(hooksDir, 'post-bash-command-log.js'), 'audit'], {
+      input: JSON.stringify({ tool_name: 'Bash', tool_input: { command: 'echo default' } }),
+      encoding: 'utf8',
+      env: { ...process.env, HOME: home, USERPROFILE: home, CLAUDE_CONFIG_DIR: undefined },
+    });
+    assert.match(
+      fs.readFileSync(path.join(home, '.claude', 'bash-commands.log'), 'utf8'),
+      /echo default/
+    );
+  }));
+
+  record(test('expands a tilde profile instead of creating a "~" directory', () => {
+    // path.resolve('~/.claude-work') would make ./~/.claude-work under the cwd,
+    // splitting the hook off from scripts/lib/agent-data-home.js, which expands.
+    const { home } = makeProfile();
+    runHook('post-bash-command-log.js', {
+      home,
+      profile: '~/.claude-work',
+      args: ['audit'],
+      stdin: JSON.stringify({ tool_name: 'Bash', tool_input: { command: 'echo tilde' } }),
+    });
+    assert.match(
+      fs.readFileSync(path.join(home, '.claude-work', 'bash-commands.log'), 'utf8'),
+      /echo tilde/
+    );
+  }));
+
+  console.log('\nmcp-health-check.js');
+
+  record(test('writes the health cache under CLAUDE_CONFIG_DIR', () => {
+    const { home, profile } = makeProfile();
+    fs.mkdirSync(home, { recursive: true });
+    // Without a configured server the hook skips the probe and never writes.
+    // The command does not exist, so the probe fails and the result is cached.
+    fs.writeFileSync(path.join(home, '.claude.json'), JSON.stringify({
+      mcpServers: { routing_probe: { command: 'ecc-no-such-mcp-binary', args: [] } },
+    }));
+    runHook('mcp-health-check.js', {
+      home,
+      profile,
+      stdin: JSON.stringify({ tool_name: 'mcp__routing_probe__ping', tool_input: {} }),
+    });
+    const cache = path.join(profile, 'mcp-health-cache.json');
+    assert.ok(fs.existsSync(cache), `expected ${cache} to exist`);
+    assert.ok(
+      !fs.existsSync(path.join(home, '.claude', 'mcp-health-cache.json')),
+      'the cache must not also land in ~/.claude'
+    );
+  }));
+
+  console.log('\nplan-canvas-sessions.js (SessionStart)');
+
+  record(test('reports open sessions recorded under CLAUDE_CONFIG_DIR', () => {
+    const { home, profile } = makeProfile();
+    writeSessions(path.join(profile, 'plan-canvas'), {
+      k1: { file: '/work/plan.md', status: 'open', pendingFeedback: [] },
+    });
+    const result = runHook('plan-canvas-sessions.js', { home, profile });
+    assert.match(result.stdout, /\/work\/plan\.md/);
+  }));
+
+  record(test('does not read ~/.claude when a profile is set', () => {
+    const { home, profile } = makeProfile();
+    // Only the home copy holds a session. A hook that ignored the profile
+    // would announce it; the right answer here is silence.
+    writeSessions(path.join(home, '.claude', 'plan-canvas'), {
+      k1: { file: '/work/leaked.md', status: 'open', pendingFeedback: [] },
+    });
+    const result = runHook('plan-canvas-sessions.js', { home, profile });
+    // Silence is the assertion here, and a hook that crashed before writing is
+    // also silent, so the exit status has to be checked first.
+    assert.strictEqual(result.status, 0, `SessionStart failed: ${result.stderr}`);
+    assert.strictEqual(result.stdout.trim(), '');
+  }));
+
+  console.log('\nplan-canvas-pending.js (Stop)');
+
+  record(test('blocks on feedback queued under CLAUDE_CONFIG_DIR', () => {
+    const { home, profile } = makeProfile();
+    const cwd = makeTempDir();
+    const artifact = path.join(cwd, 'plan.md');
+    fs.writeFileSync(artifact, '# plan\n');
+    writeSessions(path.join(profile, 'plan-canvas'), {
+      k1: {
+        key: 'k1',
+        file: artifact,
+        status: 'feedback',
+        pendingFeedback: [{ kind: 'verdict', verdict: 'request-changes', text: 'tighten step 2' }],
+      },
+    });
+    const decision = JSON.parse(runPendingHook({ home, profile, payload: { cwd } }));
+    assert.strictEqual(decision.decision, 'block');
+    assert.match(decision.reason, /tighten step 2/);
+  }));
+
+  console.log('\nproducer to consumer');
+
+  record(test('a session the library records is found by both hooks', () => {
+    // The regression this guards: the library wrote ~/.claude/plan-canvas while
+    // the hooks read CLAUDE_CONFIG_DIR/plan-canvas, so under a second profile
+    // SessionStart missed open reviews and Stop let a turn end with feedback
+    // still queued. Both ends are exercised with no state-directory override.
+    const { home, profile } = makeProfile();
+    const cwd = makeTempDir();
+    const artifact = path.join(cwd, 'design.md');
+    fs.writeFileSync(artifact, '# design\n');
+    fs.mkdirSync(home, { recursive: true });
+
+    const producer = spawnSync('node', ['-e', `
+      const store = require(${JSON.stringify(libSessions)}).createSessionStore();
+      const { session } = store.open(${JSON.stringify(artifact)});
+      store.queueFeedback(session.key, [{ kind: 'verdict', verdict: 'request-changes', text: 'needs a rollback plan' }]);
+    `], {
+      encoding: 'utf8',
+      env: {
+        ...process.env,
+        HOME: home,
+        USERPROFILE: home,
+        CLAUDE_CONFIG_DIR: profile,
+        ECC_PLAN_CANVAS_STATE_DIR: undefined,
+      },
+    });
+    assert.strictEqual(producer.status, 0, `producer failed: ${producer.stderr}`);
+    assert.ok(
+      fs.existsSync(path.join(profile, 'plan-canvas', 'sessions.json')),
+      'the library must record the session under the profile'
+    );
+
+    const sessionStart = runHook('plan-canvas-sessions.js', { home, profile });
+    assert.match(sessionStart.stdout, /design\.md/, 'SessionStart must see the open review');
+
+    const decision = JSON.parse(runPendingHook({ home, profile, payload: { cwd } }));
+    assert.strictEqual(decision.decision, 'block');
+    assert.match(decision.reason, /needs a rollback plan/);
+  }));
+
+  console.log(`\n${'='.repeat(50)}`);
+  console.log(`Passed: ${passed}`);
+  console.log(`Failed: ${failed}`);
+  console.log('='.repeat(50));
+  if (failed > 0) process.exit(1);
+}
+
+runTests();
diff --git a/tests/lib/agent-data-home.test.js b/tests/lib/agent-data-home.test.js
index 0c507c1dd..f4d255d59 100644
--- a/tests/lib/agent-data-home.test.js
+++ b/tests/lib/agent-data-home.test.js
@@ -570,6 +570,107 @@ function runTests() {
     });
   })) passed++; else failed++;
 
+  if (test('getDefaultClaudeAgentDataHome follows CLAUDE_CONFIG_DIR', () => {
+    // Claude Code points every profile-local path at CLAUDE_CONFIG_DIR. Ignoring
+    // it writes this profile's session data, logs and metrics into the default
+    // ~/.claude, where another profile reads them back.
+    withIsolatedCwd(() => {
+      withEnv({
+        CLAUDE_CONFIG_DIR: path.join(os.tmpdir(), 'ecc-profile-x'),
+        ECC_AGENT_DATA_HOME: undefined,
+      }, () => {
+        const agentDataHome = require('../../scripts/lib/agent-data-home');
+        assert.strictEqual(
+          agentDataHome.getDefaultClaudeAgentDataHome(),
+          path.join(os.tmpdir(), 'ecc-profile-x')
+        );
+      });
+    });
+  })) passed++; else failed++;
+
+  if (test('getDefaultClaudeAgentDataHome falls back to ~/.claude without the env', () => {
+    withIsolatedCwd(() => {
+      withEnv({ CLAUDE_CONFIG_DIR: undefined, ECC_AGENT_DATA_HOME: undefined }, () => {
+        const agentDataHome = require('../../scripts/lib/agent-data-home');
+        assert.strictEqual(
+          agentDataHome.getDefaultClaudeAgentDataHome(),
+          path.join(os.homedir(), '.claude')
+        );
+      });
+    });
+  })) passed++; else failed++;
+
+  if (test('a blank CLAUDE_CONFIG_DIR is ignored rather than resolving to cwd', () => {
+    // An empty or whitespace value would otherwise resolve to the process cwd and
+    // scatter profile data through whatever directory the session started in.
+    withIsolatedCwd(() => {
+      withEnv({ CLAUDE_CONFIG_DIR: '   ', ECC_AGENT_DATA_HOME: undefined }, () => {
+        const agentDataHome = require('../../scripts/lib/agent-data-home');
+        assert.strictEqual(
+          agentDataHome.getDefaultClaudeAgentDataHome(),
+          path.join(os.homedir(), '.claude')
+        );
+      });
+    });
+  })) passed++; else failed++;
+
+  if (test('security: CLAUDE_CONFIG_DIR adds a trusted profile root while preserving explicit sharing', () => {
+    // getDefaultClaudeAgentDataHome() is not only a default: it is one of the two
+    // roots resolveAllowedProjectConfigHome() will accept. Following
+    // CLAUDE_CONFIG_DIR moves that boundary with the profile, so the containment
+    // it enforces has to hold at the new location and nowhere else.
+    const projectDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-agent-data-home-cfgdir-'));
+    const homeDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-agent-data-home-cfgdir-user-'));
+    const profileDir = path.join(homeDir, '.claude-profile-x');
+    const configPath = path.join(projectDir, '.cursor', 'ecc-agent-data.json');
+    fs.mkdirSync(path.dirname(configPath), { recursive: true });
+
+    try {
+      withEnv({
+        ECC_AGENT_DATA_HOME: undefined,
+        CLAUDE_CONFIG_DIR: profileDir,
+        HOME: homeDir,
+        USERPROFILE: undefined,
+      }, () => {
+        const agentDataHome = require('../../scripts/lib/agent-data-home');
+
+        // Inside the relocated root: accepted.
+        fs.writeFileSync(
+          configPath,
+          JSON.stringify({ agentDataHome: path.join(profileDir, 'nested') }),
+          'utf8'
+        );
+        // readProjectConfigAt canonicalizes, and macOS reaches os.tmpdir()
+        // through a symlink, so compare against the resolved home.
+        assert.strictEqual(
+          agentDataHome.readProjectConfigAt(configPath),
+          path.join(fs.realpathSync(homeDir), '.claude-profile-x', 'nested')
+        );
+
+        // Preserve the explicit ~/.claude sharing root shipped in #3479.
+        // The profile root adds a trusted location; arbitrary home paths and
+        // traversal out of that profile still stay rejected.
+        fs.writeFileSync(configPath, JSON.stringify({ agentDataHome: path.join(homeDir, '.claude') }), 'utf8');
+        assert.strictEqual(agentDataHome.readProjectConfigAt(configPath), path.join(fs.realpathSync(homeDir), '.claude'));
+        const outside = [
+          path.join(profileDir, '..', 'escaped'),
+          path.join(homeDir, 'arbitrary-agent-data'),
+        ];
+        for (const candidate of outside) {
+          fs.writeFileSync(configPath, JSON.stringify({ agentDataHome: candidate }), 'utf8');
+          const { result, messages } = captureConsoleErrors(
+            () => agentDataHome.readProjectConfigAt(configPath)
+          );
+          assert.strictEqual(result, null, `expected rejection for ${candidate}`);
+          assert.ok(messages.some(message => message.includes('Ignoring unsafe agent data project config')));
+        }
+      });
+    } finally {
+      fs.rmSync(projectDir, { recursive: true, force: true });
+      fs.rmSync(homeDir, { recursive: true, force: true });
+    }
+  })) passed++; else failed++;
+
   console.log(`\n=== Test Results ===\nPassed: ${passed}\nFailed: ${failed}\n`);
   if (failed > 0) process.exit(1);
 }