diff --git a/docs/TEST_INTEGRITY.md b/docs/TEST_INTEGRITY.md
index f1cd4fc..7a04bea 100644
--- a/docs/TEST_INTEGRITY.md
+++ b/docs/TEST_INTEGRITY.md
@@ -2992,3 +2992,28 @@ test_integrity_note:
     did_relax_any_assertion: false
     if_true_explain_spec_basis: ""
 ```
+
+```yaml
+test_integrity_note:
+  change_type: new_tests
+  scenarios:
+    - id: SCN-codex-registered-mcp-runtime-dir
+      given: "The registered Codex adapter receives a Linux parent environment with a valid runtime directory, then the same environment with that variable removed"
+      when: "It produces create and resume plans for an identity-bound TORCH MCP server under an explicit model, reasoning, sandbox, and approval profile"
+      then: "Both valid plans name exactly XDG_RUNTIME_DIR; both removed-context plans omit env_vars while preserving the MCP identity, profile tokens, create/resume mode, and resume session token"
+  observable_outcomes:
+    - "The registry-backed Codex launch records contain only the one-name runtime allowlist when the real parent context has a valid value"
+    - "Removing XDG_RUNTIME_DIR removes only that allowlist, not the model, reasoning, approval, sandbox, MCP identity, or session token"
+    - "No runtime directory, DBUS address, home, PATH, token, or general parent environment value is serialized"
+  determinism_controls:
+    - "Hermetic fixture repository and explicit process-like parent environments passed to the registered adapter; no provider execution, host service, native runtime, retry, or process-wide environment mutation"
+  anti_cheat_rationale:
+    prevents:
+      - "Bypassing the registered Codex adapter to preserve launch profile or identity fields"
+      - "Hard-coding a runtime directory or forwarding DBUS, secrets, home, PATH, or the full environment"
+      - "Retaining env_vars after the parent runtime context is removed"
+      - "Claiming plan-only evidence as installed or native qualification"
+  relaxation:
+    did_relax_any_assertion: false
+    if_true_explain_spec_basis: ""
+```
diff --git a/test/fleet/mcp-adapter.test.mjs b/test/fleet/mcp-adapter.test.mjs
index e196697..bea5825 100644
--- a/test/fleet/mcp-adapter.test.mjs
+++ b/test/fleet/mcp-adapter.test.mjs
@@ -6,6 +6,7 @@ import { join } from 'node:path';
 import test from 'node:test';
 import { createClaudeAdapter } from '../../src/adapters/claude.mjs';
 import { createCodexAdapter } from '../../src/adapters/codex.mjs';
+import { createRuntimeAdapterRegistry } from '../../src/adapters/registry.mjs';
 import { openControlPlane } from '../../src/control-plane/service.mjs';
 import { analyzeRepository } from '../../src/kernel/analyze.mjs';
 import { proposeDomains } from '../../src/kernel/domains.mjs';
@@ -292,6 +293,74 @@ test('SCN-codex-mcp-runtime-dir: only a valid Linux parent runtime directory is
   }
 });
 
+test('SCN-codex-registered-mcp-runtime-dir: registered create and resume keep identity and profile tokens while an inherited runtime name is removed safely', () => {
+  const context = fixture();
+  const parent = {
+    ...context.env,
+    XDG_RUNTIME_DIR: '/run/user/1000',
+    DBUS_SESSION_BUS_ADDRESS: 'unix:path=/run/user/1000/bus',
+    HOME: '/home/fixture', PATH: '/usr/bin', TOKEN: 'not-forwarded',
+  };
+  const profile = {
+    model: 'gpt-registered', reasoning: 'high',
+    launchPolicy: { sandbox: 'workspace-write', approval: 'on-request' },
+  };
+  const plansFor = (env) => {
+    const adapter = createRuntimeAdapterRegistry({ env }).get('codex');
+    const mcp = adapter.configure({
+      repositoryRoot: context.root, areaId: context.worker, mcpEntry: MCP_SERVER,
+    }).mcp;
+    return {
+      mcp,
+      create: adapter.createSession({
+        areaId: context.worker, worktree: '/tmp/codex-registered-runtime-dir', promptFile: '/tmp/prompt.md',
+        firstMessage: 'Start registered.', mcp, ...profile,
+      }),
+      resume: adapter.resumeSession({
+        areaId: context.worker, runtimeSessionId: 'thread-registered-runtime-dir',
+        worktree: '/tmp/codex-registered-runtime-dir', message: 'Resume registered.', mcp, ...profile,
+      }),
+    };
+  };
+  const expectedEnvVars = `mcp_servers.torch-${context.worker}.env_vars=["XDG_RUNTIME_DIR"]`;
+  const expectedMcpIdentity = `mcp_servers.torch-${context.worker}.command=${JSON.stringify(process.execPath)}`;
+  const assertPreservedLaunchTokens = (plan, { expectsRuntimeName }) => {
+    const args = plan.launch.args;
+    assert.equal(args.includes('--cd'), true);
+    assert.equal(args.includes('/tmp/codex-registered-runtime-dir'), true);
+    assert.equal(args.includes('--sandbox'), true);
+    assert.equal(args.includes('workspace-write'), true);
+    assert.equal(args.includes('--ask-for-approval'), true);
+    assert.equal(args.includes('on-request'), true);
+    assert.equal(args.includes('--model'), true);
+    assert.equal(args.includes('gpt-registered'), true);
+    assert.equal(args.includes('model_reasoning_effort="high"'), true);
+    assert.equal(args.includes(expectedMcpIdentity), true);
+    assert.equal(args.includes(expectedEnvVars), expectsRuntimeName);
+    assert.equal(args.some((arg) => /env_vars=/.test(arg) && arg !== expectedEnvVars), false);
+    assert.equal(args.some((arg) => arg.includes(parent.XDG_RUNTIME_DIR)
+      || arg.includes(parent.DBUS_SESSION_BUS_ADDRESS) || arg.includes(parent.HOME)
+      || arg.includes(parent.PATH) || arg.includes(parent.TOKEN)), false);
+  };
+
+  const inherited = plansFor(parent);
+  assertPreservedLaunchTokens(inherited.create, { expectsRuntimeName: true });
+  assertPreservedLaunchTokens(inherited.resume, { expectsRuntimeName: true });
+  assert.equal(inherited.create.launch.args.includes('exec'), true);
+  assert.equal(inherited.create.launch.args.includes('resume'), false);
+  assert.equal(inherited.resume.launch.args.includes('exec'), true);
+  assert.equal(inherited.resume.launch.args.includes('resume'), true);
+  assert.equal(inherited.resume.launch.args.includes('thread-registered-runtime-dir'), true);
+
+  const withoutRuntime = { ...parent };
+  delete withoutRuntime.XDG_RUNTIME_DIR;
+  const removed = plansFor(withoutRuntime);
+  assertPreservedLaunchTokens(removed.create, { expectsRuntimeName: false });
+  assertPreservedLaunchTokens(removed.resume, { expectsRuntimeName: false });
+  assert.equal(removed.mcp.name, inherited.mcp.name);
+  assert.equal(removed.resume.launch.args.includes('thread-registered-runtime-dir'), true);
+});
+
 test('SCN-mcp-stdio: an MCP host can initialize and list the TORCH tool surface over stdio', async () => {
   const context = fixture();
   const child = spawn(process.execPath, [MCP_SERVER, '--root', context.root, '--area', context.worker], {