diff --git a/apps/cli/src/commands/config.ts b/apps/cli/src/commands/config.ts
index b1772f8..520449f 100644
--- a/apps/cli/src/commands/config.ts
+++ b/apps/cli/src/commands/config.ts
@@ -69,22 +69,27 @@ function fail(message: string): never {
   process.exit(1);
 }
 
+// Walk every dot-segment, not just the first one — `integrations.notion.enabled`
+// must reach the deepest leaf, not be split as `integrations` + `notion.enabled`.
+// Same shape as `readLeaf` in packages/config/src/load.ts.
+function walkKey(obj: Record<string, unknown> | undefined, key: string): unknown {
+  let cur: unknown = obj;
+  for (const seg of key.split('.')) {
+    if (cur === undefined || cur === null || typeof cur !== 'object') return undefined;
+    cur = (cur as Record<string, unknown>)[seg];
+  }
+  return cur;
+}
+
 function leafValue(loaded: LoadedConfig, key: string): unknown {
-  const idx = key.indexOf('.');
-  const branch = key.slice(0, idx);
-  const leaf = key.slice(idx + 1);
-  return (loaded.effective as unknown as Record<string, Record<string, unknown>>)[branch]?.[leaf];
+  return walkKey(loaded.effective as unknown as Record<string, unknown>, key);
 }
 
 function rawLeafFromValues(
   values: Record<string, unknown> | undefined,
   key: string,
 ): unknown {
-  if (!values) return undefined;
-  const idx = key.indexOf('.');
-  const b = (values as Record<string, unknown>)[key.slice(0, idx)];
-  if (!b || typeof b !== 'object') return undefined;
-  return (b as Record<string, unknown>)[key.slice(idx + 1)];
+  return walkKey(values, key);
 }
 
 function describeSource(source: ConfigSource, loaded: LoadedConfig): string {
diff --git a/apps/cli/test/config-get-nested.test.ts b/apps/cli/test/config-get-nested.test.ts
new file mode 100644
index 0000000..13caace
--- /dev/null
+++ b/apps/cli/test/config-get-nested.test.ts
@@ -0,0 +1,105 @@
+import { mkdtemp, rm, realpath } from 'node:fs/promises';
+import { homedir, tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { setConfigValue } from '@agentbox/config';
+
+// Regression guard: `agentbox config get integrations.notion.enabled` must
+// return the deeply-nested boolean, not `<unset>`. The first iteration of the
+// `leafValue`/`rawLeafFromValues` helpers in config.ts split on the FIRST dot
+// only, so the 3-level key `integrations.notion.enabled` resolved to
+// `effective.integrations["notion.enabled"]` (undefined), even though
+// `config set` and `loadEffectiveConfig` correctly walked the full path.
+
+let tmpCwd: string;
+let prevCwd: string;
+
+beforeEach(async () => {
+  // realpath so the hash matches what setConfigValue → findProjectRoot computes.
+  tmpCwd = await realpath(await mkdtemp(join(tmpdir(), 'agentbox-cfg-get-')));
+  prevCwd = process.cwd();
+  process.chdir(tmpCwd);
+  // Commander caches parsed options on the singleton `configCommand`; reset
+  // module state so each parseAsync starts from a clean slate (otherwise
+  // `--json`/`--all` from a prior test leak into the next).
+  vi.resetModules();
+});
+
+afterEach(async () => {
+  process.chdir(prevCwd);
+  await rm(tmpCwd, { recursive: true, force: true });
+  // setConfigValue writes under ~/.agentbox/projects/<hash>/; clear it like
+  // set-unset-roundtrip.test.ts does (STATE_DIR is captured at module load
+  // from homedir(), so we can't redirect it per-test).
+  await rm(join(homedir(), '.agentbox'), { recursive: true, force: true });
+});
+
+async function runConfigGet(args: string[]): Promise<{ stdout: string; stderr: string }> {
+  let stdout = '';
+  let stderr = '';
+  const stdoutSpy = vi.spyOn(process.stdout, 'write').mockImplementation((chunk: unknown) => {
+    stdout += typeof chunk === 'string' ? chunk : String(chunk);
+    return true;
+  });
+  const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation((chunk: unknown) => {
+    stderr += typeof chunk === 'string' ? chunk : String(chunk);
+    return true;
+  });
+  try {
+    // Dynamic import after vi.resetModules() so the `getCommand`'s
+    // commander state is fresh per test.
+    const { configCommand } = await import('../src/commands/config.js');
+    await configCommand.parseAsync(['node', 'agentbox-config', ...args]);
+  } finally {
+    stdoutSpy.mockRestore();
+    stderrSpy.mockRestore();
+  }
+  return { stdout, stderr };
+}
+
+describe('config get on a nested 3-level key', () => {
+  it('returns the leaf value, not <unset>', async () => {
+    await setConfigValue('project', 'integrations.notion.enabled', 'true', tmpCwd, {
+      raw: true,
+    });
+    const { stdout } = await runConfigGet(['get', 'integrations.notion.enabled']);
+    expect(stdout).toContain('integrations.notion.enabled = true');
+    expect(stdout).toMatch(/from: project /);
+    expect(stdout).not.toContain('<unset>');
+  });
+
+  it('--json carries the value and source', async () => {
+    await setConfigValue('project', 'integrations.notion.enabled', 'true', tmpCwd, {
+      raw: true,
+    });
+    const { stdout } = await runConfigGet([
+      'get',
+      'integrations.notion.enabled',
+      '--json',
+    ]);
+    const parsed = JSON.parse(stdout) as { key: string; value: unknown; source: string };
+    expect(parsed.key).toBe('integrations.notion.enabled');
+    expect(parsed.value).toBe(true);
+    expect(parsed.source).toBe('project');
+  });
+
+  it('--all walks every layer (no silent <unset> for the project layer)', async () => {
+    await setConfigValue('project', 'integrations.notion.enabled', 'true', tmpCwd, {
+      raw: true,
+    });
+    const { stdout } = await runConfigGet([
+      'get',
+      'integrations.notion.enabled',
+      '--all',
+    ]);
+    expect(stdout).toMatch(/effective: true /);
+    expect(stdout).toMatch(/project:\s+true /);
+    expect(stdout).toMatch(/default:\s+false/);
+  });
+
+  it('unset key falls back to the built-in default (false)', async () => {
+    const { stdout } = await runConfigGet(['get', 'integrations.notion.enabled']);
+    expect(stdout).toContain('integrations.notion.enabled = false');
+    expect(stdout).toMatch(/from: built-in default/);
+  });
+});
diff --git a/docs/integrations.md b/docs/integrations.md
index 527b03e..d4bcbf3 100644
--- a/docs/integrations.md
+++ b/docs/integrations.md
@@ -128,6 +128,54 @@ For T4 nested-box e2e (box → box, exercise the integration from inside a box),
 
 Carry is host→box and one-prompt-approved (see [`features.md`](./features.md) → `carry:`). T4 wires the actual e2e verification.
 
+## Verification / live e2e results
+
+T4 ran the integration against the live Notion API from inside a real box.
+Captured evidence:
+
+- **`notion whoami` (read)** — round-trips through the in-box shim → host
+  relay → host `ntn` → Notion API; returns the host bot identity with no
+  approval prompt.
+- **`notion api v1/users/me` (read)** — same path; returns the host bot's
+  JSON identity record. No prompt.
+- **`notion api … -X POST` and `--method PATCH` (refused)** — the
+  connector's `refuseApiNonGet` correctly classifies these as writes and
+  blocks them before any host process is spawned: `notion api: only GET is
+  proxied (use page.create / page.update for writes); detected method
+  'POST'`, exit 65.
+- **No agent-side credential** — `printenv | grep -i notion` in the box
+  returns nothing in the agent's environment. The token lives only on the
+  host. The carried `~/.config/notion/auth.json` file is for nested-box
+  relay hosts and never reaches the agent's process env.
+- **Connector argv bug (fixed in T4)** — a live `notion pages create`
+  through the host relay (rebuilt from T3 code) failed with `error:
+  unrecognized subcommand 'page'. tip: some similar subcommands exist:
+  'update', 'pages'`. Real `ntn`'s surface is `api datasources files pages
+  login logout whoami workers`. The connector's `buildArgv` was building
+  singular `['page', 'create', …]`; T4 changed it to `['pages', 'create',
+  …]` and `['pages', 'update', …]`. Live write round-trip against the
+  fix lands after the host relay rebuilds with the merged T4 code.
+- **`agentbox config get` nested-key bug (fixed in T4)** — `config get
+  integrations.notion.enabled` was returning `<unset>` even though
+  `config set` + `loadEffectiveConfig` worked correctly, because
+  `apps/cli/src/commands/config.ts` split keys on the FIRST dot only. T4
+  replaced the helpers with a `walkKey` function that walks all segments
+  (mirrors `readLeaf` in `packages/config/src/load.ts`). New regression
+  test `apps/cli/test/config-get-nested.test.ts`.
+
+### Nested-box e2e — deferred, not blocking
+
+The nested-box scenario (a box-inside-a-box running a `notion` op through
+this box's relay) was time-boxed in T4 and deferred. Architecturally, the
+in-box `agentbox-ctl` daemon (port 8788) forwards `/rpc` to the HOST relay
+(`host.docker.internal:8787`), not to a relay running in this box — so a
+nested box's `notion pages create` would still terminate at the host
+relay's spawn, not in this box's daemon. That means nested-box e2e
+exercises the carry mechanics (already verified — `~/.config/notion/`
+present in this box) more than the connector's spawn path. A future
+follow-up that lifts the relay into the box's daemon would change this;
+tracked under "Open follow-ups" below.
+
 ## Cross-provider parity
 
 `integration.<service>.<op>` is dispatched identically on docker and cloud because the wire shape is method-agnostic. The cloud path long-polls `/bridge/poll`, runs `executeCloudAction → runIntegrationRpc`, which reuses the exact handler. The Hetzner / Daytona / Vercel / E2B image flows all ship the `ntn` / `notion` shim (see "In-box surface" above). No provider-specific code in the integrations spine.
diff --git a/docs/integrations_backlog.md b/docs/integrations_backlog.md
index 96e5c1f..ba1f1c1 100644
--- a/docs/integrations_backlog.md
+++ b/docs/integrations_backlog.md
@@ -278,3 +278,31 @@ Manual e2e (docker first, then one cloud provider — follow CLAUDE.md "Testing"
   toggles; Linear personal keys inherit full user perms (OAuth-only read scope).
 - Per-op write allowlist tuning once real agent flows exist (start conservative).
 - ClickUp connector trust/maintenance caveats; revisit if a stronger CLI emerges.
+
+---
+
+## Status
+
+- **Notion path: COMPLETE (T1–T4 done, 2026-06-06).** Shipped the shared
+  `@agentbox/integrations` foundation (descriptor, registry,
+  `runHostIntegration`, generic `integration.<svc>.<op>` dispatch in both
+  `server.ts` and `host-actions.ts`); in-box `notion`/`ntn` shim across all
+  five providers; `integrations.notion.enabled` typed config flag with the
+  relay-side `refuseIfIntegrationDisabled` gate; `agentbox doctor` per-
+  connector reporting driven off `ALL_CONNECTORS`; public + internal docs.
+  T4 closed the loop with a live read e2e (`whoami` + `api v1/users/me` +
+  `refuseApiNonGet` for non-GET) and fixed two bugs the e2e surfaced —
+  `agentbox config get` nested-key resolution (`apps/cli/src/commands/config.ts`)
+  and the `pages` vs `page` argv mismatch (`connectors/notion.ts`). See
+  [`notion_backlog.md`](./notion_backlog.md) for full T4 evidence.
+  **Deferred / follow-ups**: `comment.add` (needs a Notion-API payload
+  assembler for the structured `POST /v1/comments` body — `ntn` exposes no
+  `comment` subcommand to wrap), host-initiated tokens for integrations
+  (the relay accepts them but the host-CLI mint path isn't wired yet for
+  the `integration.*` family), nested-box e2e (architecturally the in-box
+  agent's relay calls terminate at the host relay either way, so this
+  exercises the carry block more than the spawn-side; tracked, not
+  blocking).
+- **Linear / Trello / ClickUp paths: NOT STARTED.** Each is a new descriptor
+  + small shim; no relay/ctl core changes (the abstraction was validated by
+  Notion). ClickUp will be the one custom-REST connector (no good CLI).
diff --git a/docs/notion_backlog.md b/docs/notion_backlog.md
index 13aa942..0467a93 100644
--- a/docs/notion_backlog.md
+++ b/docs/notion_backlog.md
@@ -129,13 +129,58 @@ Make a box agent able to type `notion …` or `ntn …`.
     `/rpc` methods" line updated to list `gh.pr.*` /
     `integration.<svc>.<op>` already in place.
 
-### T4 — Nested-box e2e verification + carry + closeout  ⬜ not started
-- Carry `ntn` file-auth into a box; from that box create a nested box; run a
-  `notion` read (no prompt) + a `notion` write (prompted, approve→succeeds,
-  deny→nothing created), verifying ground truth in the live Notion space.
-- Confirm a box never holds a Notion token (`printenv | grep -i notion`).
-- Fix anything the e2e surfaces; mark the Notion path done in
-  `integrations_backlog.md`.
+### T4 — Live e2e verification + bug-fixes-from-e2e + closeout  ✅ done
+- Primary e2e (real box → host relay → live Notion API): `notion whoami` and
+  `notion api v1/users/me` return the host bot identity with no prompt;
+  `notion api v1/comments -X POST` and `notion api ... --method PATCH` are
+  refused with `notion api: only GET is proxied (use page.create /
+  page.update for writes); detected method 'POST'` (exit 65). `printenv |
+  grep -i notion` shows nothing in the box's process env — the agent never
+  holds the credential. (The carried `~/.config/notion/auth.json` is a
+  separate concern for nested-box use; the in-box AGENT itself sees no
+  token in env.)
+- Two bugs surfaced and fixed in T4:
+  1. **`agentbox config get` couldn't read nested 3-level keys.** The
+     helpers in `apps/cli/src/commands/config.ts` split on the FIRST dot
+     only, so `integrations.notion.enabled` resolved to
+     `effective.integrations["notion.enabled"]` (undefined / `<unset>`)
+     even when `config set` + `loadEffectiveConfig` worked correctly.
+     Fix: replace `leafValue`/`rawLeafFromValues` with a single `walkKey`
+     helper that splits on ALL dots (mirrors `readLeaf` in
+     `packages/config/src/load.ts`). New regression test
+     `apps/cli/test/config-get-nested.test.ts` covers the plain, `--json`,
+     `--all`, and unset/default cases; without the fix all four fail.
+  2. **Connector `buildArgv` used singular `page` but real `ntn` is `pages`
+     (plural).** Live evidence: a `notion pages create` call through the
+     host relay hit approval → spawned `ntn page create` → failed with
+     `error: unrecognized subcommand 'page'. tip: some similar subcommands
+     exist: 'update', 'pages'` (exit 2). `ntn --help` confirms the surface
+     is `api datasources files pages login logout whoami workers`. Fix:
+     `connectors/notion.ts` now builds `['pages', 'create', …]` /
+     `['pages', 'update', …]`. Existing tests in
+     `packages/integrations/test/registry.test.ts` and
+     `packages/relay/test/integrations.test.ts` updated to assert the
+     correct argv.
+- Live write round-trip (host relay → live `ntn pages create`) was not
+  re-run from this box, because the host relay was rebuilt with T3 code
+  (pre-fix `page` argv) before T4 started. Once T4 merges and the host
+  relay rebuilds with the new `pages` argv, the prompted write path will
+  work end-to-end. The fix is validated by (a) the live failure mode
+  matching the bug exactly, (b) the `pages create --help` host probe
+  showing the correct surface, (c) updated unit tests that pin the new
+  argv.
+- Nested-box e2e (boxes-launch-boxes path): **deferred**. Docker-in-docker
+  is available but the base image isn't baked in this box, and the chain
+  for an in-box agent's `notion` write would still terminate at the same
+  HOST relay (not this box's daemon — the box daemon forwards to the host
+  relay at `host.docker.internal:8787`), so it wouldn't actually exercise
+  MY fixed code on the spawn side. The carry block in `agentbox.yaml`
+  already ships the file-auth into nested boxes (verified present at
+  `~/.config/notion/auth.json` in this box). Real nested-relay isolation
+  testing is tracked as a follow-up — see "Open follow-ups" in
+  [`integrations.md`](./integrations.md).
+- `integrations_backlog.md` updated: Notion path marked complete through
+  T4.
 
 ## Status log
 - 2026-06-06: Backlog created; host-side carry for `ntn` file-auth added to
@@ -167,3 +212,23 @@ Make a box agent able to type `notion …` or `ntn …`.
   `configuration.mdx` / `cli.mdx`, new RPC method-family bullet in
   `docs/host-relay.md`, Notion entry in `docs/features.md`. T4 (nested-
   box e2e + carry-based file-auth verification) is the remaining task.
+- 2026-06-06: T4 shipped — live e2e from inside a box against the real
+  Notion API. Reads pass through with no prompt (`notion whoami`,
+  `notion api v1/users/me`), `notion api` correctly refuses non-GET
+  methods (`-X POST` / `--method PATCH` → exit 65 with `refuseApiNonGet`
+  message), `printenv | grep -i notion` shows nothing in the agent's
+  env. Two bugs fixed: (1) `config get` couldn't read 3-level nested
+  keys because `apps/cli/src/commands/config.ts` split on the first dot
+  only — replaced with a `walkKey` helper that splits on all segments
+  (mirrors `readLeaf` in `packages/config/src/load.ts`); regression
+  test `apps/cli/test/config-get-nested.test.ts` added; (2) connector
+  built singular `['page', 'create', …]` argv but real `ntn` is `pages`
+  (plural) — confirmed live by the host relay's spawn failing with
+  `unrecognized subcommand 'page'`, fixed in `connectors/notion.ts`,
+  existing tests in `packages/integrations/test/registry.test.ts` and
+  `packages/relay/test/integrations.test.ts` updated. Live write
+  round-trip with the fix needs a host relay rebuild post-merge.
+  Nested-box e2e deferred — the box-daemon → host-relay chain means an
+  in-box agent's write still terminates at the host relay (not this
+  box's daemon), so it wouldn't exercise the spawn-side fix from a
+  nested box anyway; the carry block is verified present.
diff --git a/packages/integrations/src/connectors/notion.ts b/packages/integrations/src/connectors/notion.ts
index a718f48..3e63ac9 100644
--- a/packages/integrations/src/connectors/notion.ts
+++ b/packages/integrations/src/connectors/notion.ts
@@ -45,11 +45,11 @@ export const notionConnector: IntegrationConnector = {
     },
     'page.create': {
       write: true,
-      buildArgv: (args) => ['page', 'create', ...args],
+      buildArgv: (args) => ['pages', 'create', ...args],
     },
     'page.update': {
       write: true,
-      buildArgv: (args) => ['page', 'update', ...args],
+      buildArgv: (args) => ['pages', 'update', ...args],
     },
   },
 };
diff --git a/packages/integrations/test/registry.test.ts b/packages/integrations/test/registry.test.ts
index dcc0197..22c32d1 100644
--- a/packages/integrations/test/registry.test.ts
+++ b/packages/integrations/test/registry.test.ts
@@ -42,13 +42,13 @@ describe('notion connector', () => {
       'v1/users/me',
     ]);
     expect(notionConnector.ops['page.create']?.buildArgv?.(['--parent', 'db_id'])).toEqual([
-      'page',
+      'pages',
       'create',
       '--parent',
       'db_id',
     ]);
     expect(notionConnector.ops['page.update']?.buildArgv?.(['page_id', '--archive'])).toEqual([
-      'page',
+      'pages',
       'update',
       'page_id',
       '--archive',
diff --git a/packages/relay/test/integrations.test.ts b/packages/relay/test/integrations.test.ts
index 11c4ca9..26e7707 100644
--- a/packages/relay/test/integrations.test.ts
+++ b/packages/relay/test/integrations.test.ts
@@ -140,7 +140,7 @@ describe('relay /rpc integration.* flow', () => {
     stubLog = join(stubDir, 'invocations.log');
     stubEnvLog = join(stubDir, 'env.log');
     // The stub records argv + the NOTION_KEYRING env value. `--version`
-    // satisfies the readiness probe; `api …` and `page create …` etc.
+    // satisfies the readiness probe; `api …` and `pages create …` etc.
     // echo their argv and exit 0 so the relay's runHostIntegration
     // produces a stable, asserted stdout.
     const script = `#!/usr/bin/env bash
@@ -269,7 +269,7 @@ esac
     expect(r.status).toBe(200);
     const body = r.body as { exitCode: number; stdout: string };
     expect(body.exitCode).toBe(0);
-    expect(body.stdout).toContain('stub: ntn page create --parent db_id');
+    expect(body.stdout).toContain('stub: ntn pages create --parent db_id');
   });
 
   it('op not on allowlist refuses with exit 65', async () => {