diff --git a/README.md b/README.md
index 7aa8ea1..ac73e41 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,8 @@ and the first Claude reference-fleet path:
 - an explicit-capability Claude adapter with durable-message fallback;
 - an explicit-capability Codex adapter with resumable JSONL thread capture;
 - per-domain mixed Claude/Codex runtime planning and identity-bound MCP registration plans;
+- invocation-scoped MCP injection on every Claude/Codex create and resume
+  launch, without changing the user's global runtime configuration;
 - durable-first Codex steering with native `queue` notification when available;
 - worker-first/Session-Manager-last fresh start and resume planning;
 - safe wind-down with active-work refusal and local resume snapshots.
diff --git a/docs/PORTABLE_AGENT_FLEET_SPEC.md b/docs/PORTABLE_AGENT_FLEET_SPEC.md
index eea0e30..31cc4e5 100644
--- a/docs/PORTABLE_AGENT_FLEET_SPEC.md
+++ b/docs/PORTABLE_AGENT_FLEET_SPEC.md
@@ -1482,9 +1482,13 @@ Exit gate: Claude and Codex occupy persistent domains in one Fleet and
 coordinate through TORCH rather than native vendor messaging.
 
 Implementation checkpoint (2026-09-27): the Codex adapter, mixed-runtime
-planning, identity-bound MCP configuration plans, JSONL runtime-ID capture,
-durable-first steering, and explicit degraded capabilities are implemented and
-scenario-tested with virtualized runners. The exit gate remains open until an
+planning, invocation-scoped identity-bound MCP configuration for every create
+and resume launch, JSONL runtime-ID capture, durable-first steering, and
+explicit degraded capabilities are implemented and scenario-tested with
+virtualized runners plus a real local stdio MCP handshake. Claude receives an
+ephemeral `--mcp-config`; Codex receives invocation-local `mcp_servers`
+overrides, so TORCH does not rewrite either runtime's global configuration.
+The exit gate remains open until an
 owner-authorized live Claude/Codex acceptance run demonstrates coordination;
 the automated suite intentionally incurs no provider usage.
 
diff --git a/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml b/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
index 7ef6809..b09927e 100644
--- a/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
+++ b/reports/test-audit/test-integrity-note-2026-09-27-portable-kernel.yaml
@@ -109,7 +109,7 @@ test_integrity_note:
     - id: SCN-mixed-runtime
       given: one approved Codex worker domain and one Claude Session Manager with stable Fleet identities
       when: the mixed fleet starts and winds down through virtualized runtime boundaries
-      then: provider-specific commands and runtime IDs remain separate, the manager starts last, Codex completes idle, and only resident processes are stopped
+      then: provider-specific commands and runtime IDs remain separate, every create and resume launch receives identity-bound TORCH MCP access, the manager starts last, Codex completes idle, and only resident processes are stopped
     - id: SCN-backlog-lifecycle
       given: tracked tasks in the Session Manager worktree with domain owners, dependencies, and an integration lookup
       when: tasks move through assignment, work, blocking, verification, readiness, landing, and completion
@@ -296,6 +296,7 @@ test_integrity_note:
       - MCP and CLI drifting onto separate business logic
       - launch plans that execute provider commands during preview
       - a mixed-runtime claim implemented as renamed Claude-only commands
+      - runtime sessions launching without their identity-bound TORCH tool surface
       - lost Codex thread IDs or native steering that bypasses durable messaging
       - manager-first startup or manager-first shutdown
       - passing receipts detached from the commit actually measured
diff --git a/src/adapters/claude.mjs b/src/adapters/claude.mjs
index f5dcc24..b2d2127 100644
--- a/src/adapters/claude.mjs
+++ b/src/adapters/claude.mjs
@@ -28,6 +28,16 @@ function commandRecord(command, args, cwd) {
   return { command, args, cwd, mutatesRuntime: true };
 }
 
+function mcpArgs(mcp) {
+  if (!mcp) return [];
+  if (typeof mcp.name !== 'string' || typeof mcp.command !== 'string' || !Array.isArray(mcp.args)) {
+    throw new TorchError('Claude MCP launch configuration is invalid', { code: 'INVALID_RUNTIME_INPUT' });
+  }
+  return ['--mcp-config', JSON.stringify({
+    mcpServers: { [mcp.name]: { command: mcp.command, args: mcp.args } },
+  })];
+}
+
 function mcpName(areaId) {
   return `torch-${areaId.toLowerCase().replace(/[^a-z0-9_-]+/g, '-').replace(/^-|-$/g, '')}`;
 }
@@ -85,7 +95,7 @@ export class ClaudeRuntimeAdapter {
     };
   }
 
-  createSession({ areaId, title, worktree, promptFile, firstMessage, model = 'opus', background = true } = {}) {
+  createSession({ areaId, title, worktree, promptFile, firstMessage, model = 'opus', background = true, mcp } = {}) {
     const runtimeSessionId = this.idFactory();
     const args = [];
     if (background) args.push('--bg');
@@ -94,6 +104,7 @@ export class ClaudeRuntimeAdapter {
       '--session-id', runtimeSessionId,
       '-n', `TORCH · ${text(title ?? areaId, 'title')}`,
       '--append-system-prompt-file', text(promptFile, 'promptFile'),
+      ...mcpArgs(mcp),
     );
     if (firstMessage) args.push(text(firstMessage, 'firstMessage'));
     return {
@@ -102,10 +113,10 @@ export class ClaudeRuntimeAdapter {
     };
   }
 
-  resumeSession({ areaId, runtimeSessionId, worktree, model = 'opus', message, background = true } = {}) {
+  resumeSession({ areaId, runtimeSessionId, worktree, model = 'opus', message, background = true, mcp } = {}) {
     const args = [];
     if (background) args.push('--bg');
-    args.push('--model', text(model, 'model'), '--resume', text(runtimeSessionId, 'runtimeSessionId'));
+    args.push('--model', text(model, 'model'), ...mcpArgs(mcp), '--resume', text(runtimeSessionId, 'runtimeSessionId'));
     if (message) args.push(text(message, 'message'));
     return {
       adapter: this.name, areaId: text(areaId, 'areaId'), runtimeSessionId,
diff --git a/src/adapters/codex.mjs b/src/adapters/codex.mjs
index 06b00fd..f31f4c9 100644
--- a/src/adapters/codex.mjs
+++ b/src/adapters/codex.mjs
@@ -31,6 +31,18 @@ function commandRecord(command, args, cwd) {
   return { command, args, cwd, mutatesRuntime: true };
 }
 
+function mcpArgs(mcp) {
+  if (!mcp) return [];
+  if (typeof mcp.name !== 'string' || !/^[a-z0-9_-]+$/.test(mcp.name)
+    || typeof mcp.command !== 'string' || !Array.isArray(mcp.args)) {
+    throw new TorchError('Codex MCP launch configuration is invalid', { code: 'INVALID_RUNTIME_INPUT' });
+  }
+  return [
+    '-c', `mcp_servers.${mcp.name}.command=${JSON.stringify(mcp.command)}`,
+    '-c', `mcp_servers.${mcp.name}.args=${JSON.stringify(mcp.args)}`,
+  ];
+}
+
 function mcpName(areaId) {
   return `torch-${areaId.toLowerCase().replace(/[^a-z0-9_-]+/g, '-').replace(/^-|-$/g, '')}`;
 }
@@ -89,19 +101,20 @@ export class CodexRuntimeAdapter {
       mutationPerformed: false,
       mcp: {
         name: mcpName(id),
-        command: this.executable,
-        args: ['mcp', 'add', mcpName(id), '--', this.nodeExecutable, entry, '--root', root, '--area', id],
+        command: this.nodeExecutable,
+        args: [entry, '--root', root, '--area', id],
         cwd: root,
       },
-      note: 'Apply this identity-bound MCP registration only through an owner-approved Codex configuration change.',
+      note: 'Pass this identity-bound MCP server as an invocation-scoped Codex configuration.',
     };
   }
 
-  createSession({ areaId, worktree, promptFile, firstMessage, model } = {}) {
+  createSession({ areaId, worktree, promptFile, firstMessage, model, mcp } = {}) {
     const id = text(areaId, 'areaId');
     const cwd = text(worktree, 'worktree');
     const args = [
       'exec', '--json', '--cd', cwd, '--sandbox', 'workspace-write', '--approve-for-me',
+      ...mcpArgs(mcp),
       ...optionalModelArgs(model),
       `${text(firstMessage, 'firstMessage')}\n\nRead and follow the TORCH domain prompt at ${text(promptFile, 'promptFile')}.`,
     ];
@@ -115,12 +128,13 @@ export class CodexRuntimeAdapter {
     };
   }
 
-  resumeSession({ areaId, runtimeSessionId, worktree, message, model } = {}) {
+  resumeSession({ areaId, runtimeSessionId, worktree, message, model, mcp } = {}) {
     const id = text(areaId, 'areaId');
     const sessionId = text(runtimeSessionId, 'runtimeSessionId');
     const cwd = text(worktree, 'worktree');
     const args = [
       'exec', '--json', '--cd', cwd, '--sandbox', 'workspace-write', '--approve-for-me',
+      ...mcpArgs(mcp),
       ...optionalModelArgs(model), 'resume', sessionId, text(message, 'message'),
     ];
     return {
diff --git a/src/runtime/lifecycle.mjs b/src/runtime/lifecycle.mjs
index 70ec28e..812b2ac 100644
--- a/src/runtime/lifecycle.mjs
+++ b/src/runtime/lifecycle.mjs
@@ -1,11 +1,14 @@
 import { execFileSync } from 'node:child_process';
 import { existsSync, mkdirSync, readFileSync, renameSync, writeFileSync } from 'node:fs';
 import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
 import { TorchError } from '../kernel/errors.mjs';
 import { readInstallManifest } from '../kernel/install.mjs';
 import { loadFleetDefinition } from '../kernel/worktrees.mjs';
 import { validateRuntimeAdapter } from '../adapters/runtime.mjs';
 
+const MCP_ENTRY = fileURLToPath(new URL('../mcp/server.mjs', import.meta.url));
+
 function localStateRoot(manifest) {
   const record = (manifest.external ?? []).find((entry) => entry.type === 'local-state');
   if (!record?.path) throw new TorchError('Installation manifest has no local state root', { code: 'LOCAL_STATE_MISSING' });
@@ -140,6 +143,15 @@ export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, f
     }
     validateRuntimeAdapter(runtimeAdapter);
     const identity = controlPlane.identity(area.id);
+    const runtimeIntegration = runtimeAdapter.configure({
+      repositoryRoot, areaId: area.id, mcpEntry: MCP_ENTRY,
+    });
+    if (runtimeIntegration?.mutationPerformed !== false || !runtimeIntegration?.mcp) {
+      blockers.push({
+        areaId: area.id, code: 'RUNTIME_CONFIGURATION_INVALID', runtime,
+      });
+      continue;
+    }
     const prompts = promptPaths(stateRoot, worktree, area.id);
     const runtimeConfig = config.runtimes?.[runtime] ?? {};
     const model = area.model ?? runtimeConfig.model;
@@ -148,11 +160,11 @@ export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, f
     const runtimePlan = shouldResume
       ? runtimeAdapter.resumeSession({
         areaId: area.id, runtimeSessionId: identity.runtimeSessionId, worktree: worktree.path,
-        model, background, message: startupMessage(area.id, false),
+        model, background, message: startupMessage(area.id, false), mcp: runtimeIntegration.mcp,
       })
       : runtimeAdapter.createSession({
         areaId: area.id, title: area.title, worktree: worktree.path, promptFile: prompts.combined,
-        firstMessage: startupMessage(area.id, true), model, background,
+        firstMessage: startupMessage(area.id, true), model, background, mcp: runtimeIntegration.mcp,
       });
     actions.push({
       areaId: area.id, title: area.title, mode: shouldResume ? 'resume' : 'create',
@@ -160,7 +172,8 @@ export function planFleetUp({ repositoryRoot, controlPlane, adapter, adapters, f
       requiresRuntimeIdCapture: runtimePlan.requiresRuntimeIdCapture ?? false,
       completionState: runtimePlan.completionState ?? 'starting',
       worktree: worktree.path, branch: worktree.branch, promptFile: prompts.combined,
-      promptSources: [prompts.common, prompts.area], launch: runtimePlan.launch,
+      promptSources: [prompts.common, prompts.area], mcp: runtimeIntegration.mcp,
+      launch: runtimePlan.launch,
     });
   }
 
@@ -200,6 +213,16 @@ export function planAreaUp({ repositoryRoot, controlPlane, areaId, adapter, adap
   }
   validateRuntimeAdapter(runtimeAdapter);
   const identity = controlPlane.identity(area.id);
+  const runtimeIntegration = runtimeAdapter.configure({
+    repositoryRoot, areaId: area.id, mcpEntry: MCP_ENTRY,
+  });
+  if (runtimeIntegration?.mutationPerformed !== false || !runtimeIntegration?.mcp) {
+    return {
+      action: 'area-up', projectId: manifest.projectId, areaId, fresh,
+      actions: [], blockers: [{ areaId, code: 'RUNTIME_CONFIGURATION_INVALID', runtime }],
+      canProceed: false, mutationPerformed: false,
+    };
+  }
   const prompts = promptPaths(localStateRoot(manifest), worktree, area.id);
   const runtimeConfig = config.runtimes?.[runtime] ?? {};
   const model = area.model ?? runtimeConfig.model;
@@ -208,11 +231,11 @@ export function planAreaUp({ repositoryRoot, controlPlane, areaId, adapter, adap
   const runtimePlan = shouldResume
     ? runtimeAdapter.resumeSession({
       areaId: area.id, runtimeSessionId: identity.runtimeSessionId, worktree: worktree.path,
-      model, background, message: startupMessage(area.id, false),
+      model, background, message: startupMessage(area.id, false), mcp: runtimeIntegration.mcp,
     })
     : runtimeAdapter.createSession({
       areaId: area.id, title: area.title, worktree: worktree.path, promptFile: prompts.combined,
-      firstMessage: startupMessage(area.id, true), model, background,
+      firstMessage: startupMessage(area.id, true), model, background, mcp: runtimeIntegration.mcp,
     });
   const action = {
     areaId: area.id, title: area.title, mode: shouldResume ? 'resume' : 'create',
@@ -220,7 +243,8 @@ export function planAreaUp({ repositoryRoot, controlPlane, areaId, adapter, adap
     requiresRuntimeIdCapture: runtimePlan.requiresRuntimeIdCapture ?? false,
     completionState: runtimePlan.completionState ?? 'starting',
     worktree: worktree.path, branch: worktree.branch, promptFile: prompts.combined,
-    promptSources: [prompts.common, prompts.area], launch: runtimePlan.launch,
+    promptSources: [prompts.common, prompts.area], mcp: runtimeIntegration.mcp,
+    launch: runtimePlan.launch,
   };
   return {
     action: 'area-up', projectId: manifest.projectId, areaId, fresh,
diff --git a/test/fleet/lifecycle.test.mjs b/test/fleet/lifecycle.test.mjs
index b773cc1..b7d7014 100644
--- a/test/fleet/lifecycle.test.mjs
+++ b/test/fleet/lifecycle.test.mjs
@@ -48,6 +48,8 @@ test('SCN-fleet-fresh-resume: workers start before manager and stable identities
   const fresh = planFleetUp({ repositoryRoot: fixture.root, controlPlane: control, adapter, fresh: true });
   assert.equal(fresh.actions.at(-1).areaId, 'session-manager');
   assert.equal(fresh.actions.every((action) => action.mode === 'create'), true);
+  assert.equal(fresh.actions.every((action) => action.mcp.args.includes(action.areaId)), true);
+  assert.equal(fresh.actions.every((action) => action.launch.args.includes('--mcp-config')), true);
   assert.equal(fresh.mutationPerformed, false);
 
   const launches = [];
@@ -133,7 +135,10 @@ test('SCN-mixed-runtime: Codex and Claude share stable identities while planning
   assert.equal(plan.actions[0].areaId, fixture.worker);
   assert.equal(plan.actions[0].runtime, 'codex');
   assert.equal(plan.actions[0].launch.args[0], 'exec');
+  assert.equal(plan.actions[0].launch.args.some((arg) => arg.includes('mcp_servers.')), true);
+  assert.equal(plan.actions[0].launch.args.some((arg) => arg.includes(fixture.worker)), true);
   assert.equal(plan.actions.at(-1).runtime, 'claude');
+  assert.equal(plan.actions.at(-1).launch.args.includes('--mcp-config'), true);
   assert.equal(plan.actions.at(-1).runtimeSessionId, 'claude-manager-1');
 
   const started = startFleet({
diff --git a/test/fleet/mcp-adapter.test.mjs b/test/fleet/mcp-adapter.test.mjs
index c12474e..e760db1 100644
--- a/test/fleet/mcp-adapter.test.mjs
+++ b/test/fleet/mcp-adapter.test.mjs
@@ -83,12 +83,16 @@ test('SCN-claude-adapter: planning is deterministic, capabilities are honest, an
   assert.equal(configuration.mcp.args.at(-1), context.worker);
   const launch = adapter.createSession({
     areaId: context.worker, title: 'Core', worktree: '/tmp/core', promptFile: '/tmp/core.md',
-    firstMessage: 'Resume TASK-1.', model: 'opus',
+    firstMessage: 'Resume TASK-1.', model: 'opus', mcp: configuration.mcp,
   });
   assert.equal(launch.runtimeSessionId, 'runtime-123');
   assert.deepEqual(launch.launch.args.slice(0, 7), [
     '--bg', '--model', 'opus', '--session-id', 'runtime-123', '-n', 'TORCH · Core',
   ]);
+  const mcpIndex = launch.launch.args.indexOf('--mcp-config');
+  const launchMcp = JSON.parse(launch.launch.args[mcpIndex + 1]).mcpServers[`torch-${context.worker}`];
+  assert.equal(launchMcp.command, process.execPath);
+  assert.equal(launchMcp.args.at(-1), context.worker);
   assert.equal(calls.length, 0, 'creating a launch plan must not execute Claude');
   assert.equal(adapter.getStatus({ runtimeSessionId: 'runtime-123' }).status, 'idle');
   assert.equal(calls.length, 1);
@@ -110,14 +114,13 @@ test('SCN-codex-adapter: turns are resumable, identity-bound, durable, and capab
     repositoryRoot: context.root, areaId: context.worker, mcpEntry: MCP_SERVER,
   });
   assert.equal(configuration.mutationPerformed, false);
-  assert.deepEqual(configuration.mcp.args.slice(0, 4), [
-    'mcp', 'add', `torch-${context.worker}`, '--',
-  ]);
+  assert.equal(configuration.mcp.command, process.execPath);
+  assert.equal(configuration.mcp.args[0], MCP_SERVER);
   assert.equal(configuration.mcp.args.includes(context.worker), true);
 
   const launch = adapter.createSession({
     areaId: context.worker, worktree: '/tmp/codex-core', promptFile: '/tmp/codex-core.md',
-    firstMessage: 'Resume TASK-2.', model: 'gpt-test',
+    firstMessage: 'Resume TASK-2.', model: 'gpt-test', mcp: configuration.mcp,
   });
   assert.equal(launch.runtimeSessionId, null);
   assert.equal(launch.requiresRuntimeIdCapture, true);
@@ -125,6 +128,8 @@ test('SCN-codex-adapter: turns are resumable, identity-bound, durable, and capab
   assert.deepEqual(launch.launch.args.slice(0, 7), [
     'exec', '--json', '--cd', '/tmp/codex-core', '--sandbox', 'workspace-write', '--approve-for-me',
   ]);
+  assert.equal(launch.launch.args.includes(`mcp_servers.torch-${context.worker}.command=${JSON.stringify(process.execPath)}`), true);
+  assert.equal(launch.launch.args.some((arg) => arg.includes(MCP_SERVER)), true);
   assert.equal(calls.length, 0, 'creating a launch plan must not execute Codex');
   assert.equal(adapter.captureRuntimeId({
     areaId: context.worker,
@@ -133,10 +138,11 @@ test('SCN-codex-adapter: turns are resumable, identity-bound, durable, and capab
 
   const resumed = adapter.resumeSession({
     areaId: context.worker, runtimeSessionId: 'codex-thread-123', worktree: '/tmp/codex-core',
-    message: 'Continue.',
+    message: 'Continue.', mcp: configuration.mcp,
   });
   assert.equal(resumed.launch.args.includes('resume'), true);
   assert.equal(resumed.launch.args.includes('codex-thread-123'), true);
+  assert.equal(resumed.launch.args.some((arg) => arg.includes(MCP_SERVER)), true);
 
   const delivery = adapter.sendOrSteer({
     controlPlane: control, recipient: context.worker, body: 'Check your durable inbox.',