fix(reviewer-workflow): address review — in-process mutation authority, no /tmp lock (#199)

Addresses the sysadmin REQUEST_CHANGES on PR #203 (reviewed head
10d2644790):

1. Lock redesigned; /tmp file removed entirely. The mutation authority is
   now an in-process record (_MUTATION_AUTHORITY) plus an environment
   session lock (GITEA_SESSION_PROFILE_LOCK) exported at server launch:
   - in-process record cannot be spoofed by other local processes, cannot
     go stale across sessions, and cannot race concurrent agents;
   - the env lock is inherited by child CLI processes, so review_pr.py can
     refuse an ad-hoc GITEA_MCP_PROFILE role escalation without any shared
     file; a missing env lock (direct operator CLI use) stays allowed;
   - silent except-pass writes are gone; an unresolvable profile fails
     closed.
2. Standard reviewer workflow unbroken: verify_mutation_authority seeds
   itself from the live config-resolved context at the first mutation gate
   (approved preflight path whoami -> eligibility -> review/merge), and now
   runs as the final gate after eligibility, reusing the identity that
   eligibility proved (no extra /user call).
3. Trailing whitespace removed from review_pr.py (git diff --check clean).
4. Module-global verify_mutation_authority no-op bypass removed from
   tests/test_mcp_server.py; replaced with a tests/conftest.py autouse
   fixture that only resets per-process state (_MUTATION_AUTHORITY,
   _IDENTITY_CACHE, session lock env) between tests — the gate itself
   stays live in every test.
5. Tests rewritten for the new design: seeding on first verify, unresolved
   profile fails closed, remote/profile/identity mismatches fail closed,
   session-lock env mismatch rejected, foreign-pid authority reseeded,
   unauthorized author->reviewer pivot blocked, authorized pivot allowed;
   CLI: mismatch blocked, match allowed, no-lock allowed.
6. Rebased onto current master (c6fd0fd).

Closes #199
Refs #194

Co-Authored-By: Claude Fable 5 <[email protected]>

mcp_server.py

@@ -22,11 +22,42 @@ import contextlib
 import subprocess
 
 
-LOCK_FILE = "/tmp/gitea_mutation_authority.lock"
+# Mutation-authority record (#199, refs #194). Deliberately in-process, NOT a
+# file: a /tmp lock is host-global, writable (spoofable) by any local process,
+# goes silently stale across sessions, and races between concurrent agent
+# sessions. This record lives and dies with the MCP server process, so it can
+# never be forged from outside or leak between sessions. The CLI side-channel
+# (a subprocess overriding GITEA_MCP_PROFILE to escalate roles) is covered by
+# SESSION_PROFILE_LOCK_ENV below: the server exports its launch profile into
+# the environment, children inherit it, and reviewer CLIs (review_pr.py)
+# refuse to run under a different resolved profile.
+_MUTATION_AUTHORITY: dict | None = None
 
-def record_mutation_authority(profile_name: str | None, identity: str | None, remote: str | None, task: str | None):
+SESSION_PROFILE_LOCK_ENV = "GITEA_SESSION_PROFILE_LOCK"
-    """Record the resolved capability context to fail-closed lock file."""
+
-    data = {
+
+def _export_session_profile_lock():
+    """Export this process's launch profile for child CLI processes.
+
+    setdefault: an already-locked environment (outer session) wins, so a
+    nested launch cannot relabel the session.
+    """
+    try:
+        name = (get_profile().get("profile_name") or "").strip()
+        if name:
+            os.environ.setdefault(SESSION_PROFILE_LOCK_ENV, name)
+    except Exception:
+        # Profile resolution problems surface loudly on the first real call;
+        # the lock export must not mask them here at import time.
+        pass
+
+
+def record_mutation_authority(profile_name: str | None, identity: str | None,
+                              remote: str | None, task: str | None):
+    """Record the resolved capability context for this process (fail-closed
+    consumers in verify_mutation_authority)."""
+    global _MUTATION_AUTHORITY
+    _MUTATION_AUTHORITY = {
         "initial_profile": profile_name,
         "initial_identity": identity,
         "current_profile": profile_name,
@@ -35,48 +66,83 @@ def record_mutation_authority(profile_name: str | None, identity: str | None, re
         "task": task,
         "role_pivot_authorized": False,
         "role_pivot_record": None,
+        "pid": os.getpid(),
     }
-    try:
-        with open(LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(data, f)
-    except Exception:
-        pass
 
-def verify_mutation_authority(remote: str | None, host: str | None = None, required_role: str = "reviewer"):
-    """Verify that the current mutation matches the locked capability context."""
-    if not os.path.exists(LOCK_FILE):
-        raise RuntimeError("Mutation authority lock is missing (fail closed)")
 
-    try:
+def verify_mutation_authority(remote: str | None, host: str | None = None,
-        with open(LOCK_FILE, "r", encoding="utf-8") as f:
+                              required_role: str = "reviewer",
-            data = json.load(f)
+                              active_identity: str | None = None):
-    except Exception as e:
+    """Verify the current mutation matches this process's recorded authority.
-        raise RuntimeError(f"Could not read mutation authority lock: {e} (fail closed)")
 
-    if data.get("remote") != remote:
+    Fail-closed rules:
-        raise RuntimeError(
+    - No recorded authority (or one from another process after a fork) is
-            f"Mutation remote '{remote}' does not match locked remote '{data.get('remote')}' (fail closed)"
+      seeded from the live, config-resolved context — the approved preflight
-        )
+      path (whoami → eligibility → mutation) therefore works without an
+      explicit resolve call — but an unresolvable profile still fails closed.
+    - GITEA_SESSION_PROFILE_LOCK (set by the launching session) must match
+      the active profile: a mid-session GITEA_MCP_PROFILE override flips the
+      active profile away from the lock and is refused.
+    - Remote, profile, and identity must match the recorded authority.
+    - An author→reviewer pivot requires an authorized pivot record
+      (gitea_activate_profile in dynamic mode); it can never be improvised.
+    """
+    global _MUTATION_AUTHORITY
 
     profile = get_profile()
     active_profile = profile.get("profile_name")
-    h = host or (REMOTES.get(remote, {}).get("host") if remote in REMOTES else None)
+    if active_identity is None:
-    active_identity = _authenticated_username(h) if h else None
+        # Callers that already proved the identity (eligibility gate) pass it
+        # in; otherwise resolve it here (cached, read-only).
+        h = host or (REMOTES.get(remote, {}).get("host") if remote in REMOTES else None)
+        active_identity = _authenticated_username(h) if h else None
+
+    if not active_profile:
+        raise RuntimeError(
+            "Mutation authority unavailable: active profile unresolved (fail closed)"
+        )
+
+    session_lock = (os.environ.get(SESSION_PROFILE_LOCK_ENV) or "").strip()
+    if session_lock and session_lock != active_profile:
+        raise RuntimeError(
+            f"Active profile '{active_profile}' does not match the session "
+            f"profile lock '{session_lock}' — profile side-channel override "
+            "rejected (fail closed)"
+        )
+
+    data = _MUTATION_AUTHORITY
+    if data is None or data.get("pid") != os.getpid():
+        # First mutation gate in this process (approved preflight path):
+        # seed the authority from the live context, then verify against it.
+        record_mutation_authority(
+            active_profile, active_identity, remote, "seeded-at-mutation-gate"
+        )
+        data = _MUTATION_AUTHORITY
+
+    if data.get("remote") != remote:
+        raise RuntimeError(
+            f"Mutation remote '{remote}' does not match locked remote "
+            f"'{data.get('remote')}' (fail closed)"
+        )
 
     locked_profile = data.get("current_profile")
     locked_identity = data.get("current_identity")
-
     if active_profile != locked_profile or active_identity != locked_identity:
         raise RuntimeError(
             f"Mutation profile '{active_profile}' or identity '{active_identity}' "
-            f"does not match locked authority (profile: '{locked_profile}', identity: '{locked_identity}') (fail closed)"
+            f"does not match locked authority (profile: '{locked_profile}', "
+            f"identity: '{locked_identity}') (fail closed)"
         )
 
-    # Check reviewer/author role pivot boundaries
+    # Reviewer/author role pivot boundary: only an authorized pivot
-    if required_role == "reviewer" and "author" in str(data.get("initial_profile")).lower() and "reviewer" in str(active_profile).lower():
+    # (recorded by gitea_activate_profile) may cross author → reviewer.
+    if (required_role == "reviewer"
+            and "author" in str(data.get("initial_profile")).lower()
+            and "reviewer" in str(active_profile).lower()):
         if not data.get("role_pivot_authorized"):
             raise RuntimeError(
-                "Attempted reviewer mutation from author session without authorized role pivot (fail closed)"
+                "Attempted reviewer mutation from author session without "
+                "authorized role pivot (fail closed)"
             )
 
 # Resolve the project root. MCP clients must launch this script directly with
@@ -1050,12 +1116,6 @@ def gitea_submit_pr_review(
     }
     reasons = result["reasons"]
 
-    try:
-        verify_mutation_authority(remote, host, required_role="reviewer")
-    except RuntimeError as e:
-        reasons.append(str(e))
-        return result
-
     # Gate 1 — valid review action (no mutation on unknown action).
     if action not in _REVIEW_ACTIONS:
         reasons.append(
@@ -1108,6 +1168,17 @@ def gitea_submit_pr_review(
         reasons.append("PR head SHA unavailable (fail closed)")
         return result
 
+    # Gate 5 — in-process mutation authority (#199): the last check before
+    # the mutating POST, using the identity the eligibility gate proved.
+    # A profile/identity flip or side-channel override between preflight
+    # and mutation fails closed here.
+    try:
+        verify_mutation_authority(remote, host, required_role="reviewer",
+                                  active_identity=auth_user)
+    except RuntimeError as e:
+        reasons.append(str(e))
+        return result
+
     # All gates passed — perform the single mutating call.
     h, o, r = _resolve(remote, host, org, repo)
     try:
@@ -1376,12 +1447,6 @@ def gitea_merge_pr(
     }
     reasons = result["reasons"]
 
-    try:
-        verify_mutation_authority(remote, host, required_role="reviewer")
-    except RuntimeError as e:
-        reasons.append(str(e))
-        return result
-
     # Gate 1 — valid merge method (no API call on a bad method).
     if do not in _MERGE_METHODS:
         reasons.append(
@@ -1460,6 +1525,17 @@ def gitea_merge_pr(
         reasons.append("self-merge blocked (authenticated user is PR author)")
         return result
 
+    # Gate 7 — in-process mutation authority (#199): the last check before
+    # the merge mutation, using the identity the eligibility gate proved.
+    # A profile/identity flip or side-channel override between preflight
+    # and merge fails closed here.
+    try:
+        verify_mutation_authority(remote, host, required_role="reviewer",
+                                  active_identity=auth_user)
+    except RuntimeError as e:
+        reasons.append(str(e))
+        return result
+
     # All gates passed — perform the single merge mutation.
     try:
         auth = _auth(h)
@@ -3058,24 +3134,21 @@ def gitea_activate_profile(
     after_profile = get_profile()["profile_name"]
     after_identity = _authenticated_username(h) if h else None
 
-    # 4.5 Record pivot in mutation authority lock
+    # 4.5 Record the authorized pivot in the in-process mutation authority
-    if os.path.exists(LOCK_FILE):
+    # and keep the session profile lock in sync — this is the ONLY path that
-        try:
+    # may authorize an author→reviewer role pivot.
-            with open(LOCK_FILE, "r", encoding="utf-8") as f:
+    if _MUTATION_AUTHORITY is not None:
-                lock_data = json.load(f)
+        _MUTATION_AUTHORITY["current_profile"] = after_profile
-            lock_data["current_profile"] = after_profile
+        _MUTATION_AUTHORITY["current_identity"] = after_identity
-            lock_data["current_identity"] = after_identity
+        _MUTATION_AUTHORITY["role_pivot_authorized"] = True
-            lock_data["role_pivot_authorized"] = True
+        _MUTATION_AUTHORITY["role_pivot_record"] = {
-            lock_data["role_pivot_record"] = {
+            "from_profile": before_profile,
-                "from_profile": before_profile,
+            "to_profile": after_profile,
-                "to_profile": after_profile,
+            "from_identity": before_identity,
-                "from_identity": before_identity,
+            "to_identity": after_identity,
-                "to_identity": after_identity
+        }
-            }
+    if os.environ.get(SESSION_PROFILE_LOCK_ENV) and after_profile:
-            with open(LOCK_FILE, "w", encoding="utf-8") as f:
+        os.environ[SESSION_PROFILE_LOCK_ENV] = after_profile
-                json.dump(lock_data, f)
-        except Exception:
-            pass
 
     # 5. Audit the switch if auditing is on
     _audit(
@@ -3588,4 +3661,8 @@ def gitea_resolve_task_capability(
 # ── Entry point ───────────────────────────────────────────────────────────────
 
 if __name__ == "__main__":
+    # Lock this session's launch profile into the environment so child CLI
+    # processes (e.g. review_pr.py) can detect and refuse profile
+    # side-channel overrides (#199).
+    _export_session_profile_lock()
     mcp.run(transport="stdio")

review_pr.py

@@ -60,28 +60,31 @@ def main(argv=None):
 
     host, org, repo = resolve_remote(args)
 
-    # ── Mutation Authority context wall check (Issue #194) ──
+    # ── Reviewer mutation side-channel wall (#199, refs #194) ──
-    LOCK_FILE = "/tmp/gitea_mutation_authority.lock"
+    # The launching MCP session exports GITEA_SESSION_PROFILE_LOCK with the
-    
+    # profile it was started with; child processes inherit it. If this CLI
-    if os.path.exists(LOCK_FILE):
+    # resolves a different profile — e.g. an ad-hoc GITEA_MCP_PROFILE
+    # override escalating an author-bound session to reviewer — refuse
+    # before any API call. No lock in the environment means no session
+    # context (direct operator CLI use), which stays allowed. Unlike a /tmp
+    # lock file, the environment is per-process-tree: other sessions cannot
+    # spoof it and it cannot go stale across sessions.
+    session_lock = (os.environ.get("GITEA_SESSION_PROFILE_LOCK") or "").strip()
+    if session_lock:
         try:
-            with open(LOCK_FILE, "r", encoding="utf-8") as f:
+            cli_profile = (get_profile().get("profile_name") or "").strip()
-                lock_data = json.load(f)
-            
-            # Resolve current CLI profile
-            cli_profile = get_profile().get("profile_name")
-            locked_profile = lock_data.get("current_profile")
-            
-            if cli_profile != locked_profile:
-                print(
-                    f"Mismatched active profile vs mutation profile (CLI override rejected): "
-                    f"CLI profile '{cli_profile}' does not match locked active profile '{locked_profile}' (fail closed)",
-                    file=sys.stderr
-                )
-                return 3
         except Exception as e:
             print(f"Mutation authority check failed: {e}", file=sys.stderr)
             return 3
+        if cli_profile != session_lock:
+            print(
+                f"Mismatched active profile vs session profile lock "
+                f"(CLI override rejected): CLI profile '{cli_profile}' does "
+                f"not match locked session profile '{session_lock}' "
+                f"(fail closed)",
+                file=sys.stderr,
+            )
+            return 3
 
     body = args.body
     if args.body_file:

tests/conftest.py

@@ -0,0 +1,28 @@
+"""Shared pytest fixtures for the Gitea-Tools test suite."""
+import sys
+
+import pytest
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+
+@pytest.fixture(autouse=True)
+def _reset_mutation_authority(monkeypatch):
+    """Isolate the in-process mutation authority between tests (#199).
+
+    The mutation-authority gate stays LIVE in every test — this fixture only
+    clears the per-process record and the session profile lock so one test's
+    seeded authority (or an intentionally mismatched one) cannot leak into
+    the next test. It must never replace verify_mutation_authority with a
+    no-op: individual tests that need a specific authority state set it up
+    explicitly.
+    """
+    monkeypatch.delenv("GITEA_SESSION_PROFILE_LOCK", raising=False)
+    try:
+        import mcp_server
+    except Exception:
+        yield
+        return
+    monkeypatch.setattr(mcp_server, "_MUTATION_AUTHORITY", None)
+    monkeypatch.setattr(mcp_server, "_IDENTITY_CACHE", {})
+    yield

tests/test_mcp_server.py

@@ -38,9 +38,6 @@ from gitea_auth import get_profile  # noqa: E402
 import gitea_config  # noqa: E402
 
 import mcp_server
-# Globally disable verification check for existing isolated unit tests
-_real_verify = mcp_server.verify_mutation_authority
-mcp_server.verify_mutation_authority = lambda *args, **kwargs: None
 
 FAKE_AUTH = "Basic dGVzdDp0ZXN0"
 
@@ -2304,87 +2301,119 @@ class TestIssueCommentPermissionSeparation(unittest.TestCase):
 
 
 class TestVerifyMutationAuthority(unittest.TestCase):
-    """Test verification lock logic under various configurations."""
+    """In-process mutation authority (#199, refs #194).
+
+    The authority record lives in mcp_server._MUTATION_AUTHORITY (per
+    process, reset between tests by conftest); the CLI side-channel is
+    covered by the GITEA_SESSION_PROFILE_LOCK environment lock. There is no
+    lock file — nothing here touches /tmp.
+    """
 
     def setUp(self):
         self.patch_profile = patch("mcp_server.get_profile")
         self.mock_profile = self.patch_profile.start()
         self.patch_username = patch("mcp_server._authenticated_username")
         self.mock_username = self.patch_username.start()
-
+        self.mock_profile.return_value = {"profile_name": "prgs-reviewer"}
-        # Restore real function for these tests
+        self.mock_username.return_value = "sysadmin"
-        self._old_verify = mcp_server.verify_mutation_authority
-        mcp_server.verify_mutation_authority = _real_verify
 
     def tearDown(self):
         self.patch_profile.stop()
         self.patch_username.stop()
-        mcp_server.verify_mutation_authority = self._old_verify
-        # Clean up lock file
-        if os.path.exists("/tmp/gitea_mutation_authority.lock"):
-            os.remove("/tmp/gitea_mutation_authority.lock")
 
-    def test_missing_lock_fails_closed(self):
+    def _authority(self, **overrides):
-        if os.path.exists("/tmp/gitea_mutation_authority.lock"):
+        data = {
-            os.remove("/tmp/gitea_mutation_authority.lock")
+            "initial_profile": "prgs-reviewer",
+            "initial_identity": "sysadmin",
+            "current_profile": "prgs-reviewer",
+            "current_identity": "sysadmin",
+            "remote": "prgs",
+            "task": "review_pr",
+            "role_pivot_authorized": False,
+            "role_pivot_record": None,
+            "pid": os.getpid(),
+        }
+        data.update(overrides)
+        mcp_server._MUTATION_AUTHORITY = data
+
+    def test_missing_authority_seeds_from_live_context(self):
+        # Approved preflight path (whoami → eligibility → mutation): the
+        # first mutation gate seeds the authority instead of failing closed,
+        # so the standard reviewer workflow keeps working.
+        mcp_server._MUTATION_AUTHORITY = None
+        mcp_server.verify_mutation_authority("prgs")
+        seeded = mcp_server._MUTATION_AUTHORITY
+        self.assertIsNotNone(seeded)
+        self.assertEqual(seeded["current_profile"], "prgs-reviewer")
+        self.assertEqual(seeded["current_identity"], "sysadmin")
+        self.assertEqual(seeded["remote"], "prgs")
+
+    def test_unresolved_profile_fails_closed(self):
+        self.mock_profile.return_value = {}
+        mcp_server._MUTATION_AUTHORITY = None
         with self.assertRaises(RuntimeError) as ctx:
-            _real_verify("prgs")
+            mcp_server.verify_mutation_authority("prgs")
-        self.assertIn("lock is missing", str(ctx.exception))
+        self.assertIn("profile unresolved", str(ctx.exception))
 
     def test_mismatched_remote_fails(self):
-        with open("/tmp/gitea_mutation_authority.lock", "w", encoding="utf-8") as f:
+        self._authority(remote="dadeschools")
-            json.dump({
-                "remote": "dadeschools",
-                "current_profile": "prgs-reviewer",
-                "current_identity": "sysadmin"
-            }, f)
         with self.assertRaises(RuntimeError) as ctx:
-            _real_verify("prgs")
+            mcp_server.verify_mutation_authority("prgs")
         self.assertIn("does not match locked remote", str(ctx.exception))
 
-    def test_mismatched_profile_fails(self):
+    def test_profile_flip_after_record_fails(self):
-        with open("/tmp/gitea_mutation_authority.lock", "w", encoding="utf-8") as f:
+        # Authority was recorded as author; the active profile now resolves
-            json.dump({
+        # as reviewer (e.g. an env-var flip mid-session) — refuse.
-                "remote": "prgs",
+        self._authority(
-                "current_profile": "prgs-author",
+            initial_profile="prgs-author",
-                "current_identity": "jcwalker3"
+            initial_identity="jcwalker3",
-            }, f)
+            current_profile="prgs-author",
-        self.mock_profile.return_value = {"profile_name": "prgs-reviewer"}
+            current_identity="jcwalker3",
-        self.mock_username.return_value = "sysadmin"
+        )
-
         with self.assertRaises(RuntimeError) as ctx:
-            _real_verify("prgs")
+            mcp_server.verify_mutation_authority("prgs")
         self.assertIn("does not match locked authority", str(ctx.exception))
 
-    def test_author_to_reviewer_pivot_blocked_without_authorization(self):
+    def test_session_lock_env_mismatch_fails(self):
-        with open("/tmp/gitea_mutation_authority.lock", "w", encoding="utf-8") as f:
+        # The launching session locked the environment to the author
-            json.dump({
+        # profile; the active profile resolves as reviewer — side-channel
-                "remote": "prgs",
+        # override rejected even with a matching in-process authority.
-                "initial_profile": "prgs-author",
+        self._authority()
-                "initial_identity": "jcwalker3",
+        with patch.dict(os.environ,
-                "current_profile": "prgs-reviewer",
+                        {"GITEA_SESSION_PROFILE_LOCK": "prgs-author"}):
-                "current_identity": "sysadmin",
+            with self.assertRaises(RuntimeError) as ctx:
-                "role_pivot_authorized": False
+                mcp_server.verify_mutation_authority("prgs")
-            }, f)
+        self.assertIn("side-channel override rejected", str(ctx.exception))
-        self.mock_profile.return_value = {"profile_name": "prgs-reviewer"}
-        self.mock_username.return_value = "sysadmin"
 
+    def test_foreign_pid_authority_is_not_trusted(self):
+        # An authority record from another process (fork leftovers) is
+        # discarded and reseeded from the live context, never reused.
+        self._authority(current_profile="prgs-author", pid=os.getpid() + 1)
+        mcp_server.verify_mutation_authority("prgs")
+        self.assertEqual(
+            mcp_server._MUTATION_AUTHORITY["current_profile"], "prgs-reviewer"
+        )
+        self.assertEqual(mcp_server._MUTATION_AUTHORITY["pid"], os.getpid())
+
+    def test_author_to_reviewer_pivot_blocked_without_authorization(self):
+        self._authority(
+            initial_profile="prgs-author",
+            initial_identity="jcwalker3",
+        )
         with self.assertRaises(RuntimeError) as ctx:
-            _real_verify("prgs", required_role="reviewer")
+            mcp_server.verify_mutation_authority("prgs", required_role="reviewer")
         self.assertIn("without authorized role pivot", str(ctx.exception))
 
-    def test_allowed_when_match(self):
+    def test_authorized_pivot_is_allowed(self):
-        with open("/tmp/gitea_mutation_authority.lock", "w", encoding="utf-8") as f:
+        self._authority(
-            json.dump({
+            initial_profile="prgs-author",
-                "remote": "prgs",
+            initial_identity="jcwalker3",
-                "initial_profile": "prgs-reviewer",
+            role_pivot_authorized=True,
-                "initial_identity": "sysadmin",
+        )
-                "current_profile": "prgs-reviewer",
+        mcp_server.verify_mutation_authority("prgs", required_role="reviewer")
-                "current_identity": "sysadmin",
-                "role_pivot_authorized": False
-            }, f)
-        self.mock_profile.return_value = {"profile_name": "prgs-reviewer"}
-        self.mock_username.return_value = "sysadmin"
 
-        # Should pass without exception
+    def test_allowed_when_match(self):
-        _real_verify("prgs")
+        self._authority()
+        with patch.dict(os.environ,
+                        {"GITEA_SESSION_PROFILE_LOCK": "prgs-reviewer"}):
+            mcp_server.verify_mutation_authority("prgs")

tests/test_review_pr.py

@@ -112,39 +112,23 @@ class TestAPIPayload(unittest.TestCase):
 
 
 class TestMutationAuthorityLock(unittest.TestCase):
-    """Issue #194: verify that the CLI tool rejects profile overrides when mismatched with lock."""
+    """#199 (refs #194): the CLI refuses to run under a profile that differs
+    from the session profile lock exported by the launching MCP session."""
 
     @patch("review_pr.get_profile")
-    def test_cli_blocked_on_profile_mismatch(self, mock_get_profile):
+    def test_cli_blocked_on_session_lock_mismatch(self, mock_get_profile):
+        # An author-bound session exported the lock; the CLI resolves a
+        # reviewer profile (GITEA_MCP_PROFILE side-channel override) — reject
+        # before any API call.
         mock_get_profile.return_value = {"profile_name": "prgs-reviewer"}
-
-        original_exists = os.path.exists
-        def conditional_exists(path):
-            if "gitea_mutation_authority.lock" in str(path):
-                return True
-            return original_exists(path)
-
-        original_open = open
-        def conditional_open(file, *args, **kwargs):
-            if "gitea_mutation_authority.lock" in str(file):
-                return io.StringIO('{"current_profile": "prgs-author"}')
-            return original_open(file, *args, **kwargs)
-
-        from _pytest.monkeypatch import MonkeyPatch
         import io
         buf = io.StringIO()
-        monkeypatch = MonkeyPatch()
+        with patch.dict(os.environ,
-        monkeypatch.setattr(sys, "stderr", buf)
+                        {"GITEA_SESSION_PROFILE_LOCK": "prgs-author"}), \
-
+             patch.object(sys, "stderr", buf):
-        with patch("os.path.exists", side_effect=conditional_exists), \
+            rc = review_pr.main([
-             patch("builtins.open", side_effect=conditional_open):
+                "--pr-number", "81", "--event", "APPROVE",
-            try:
+            ])
-                rc = review_pr.main([
-                    "--pr-number", "81", "--event", "APPROVE",
-                ])
-            finally:
-                monkeypatch.undo()
-
         self.assertEqual(rc, 3)
         msg = buf.getvalue().lower()
         self.assertIn("cli override rejected", msg)
@@ -155,21 +139,22 @@ class TestMutationAuthorityLock(unittest.TestCase):
     def test_cli_allowed_on_profile_match(self, _auth, mock_api, mock_get_profile):
         mock_get_profile.return_value = {"profile_name": "prgs-reviewer"}
         mock_api.side_effect = [FAKE_PR_DATA, {}]
+        with patch.dict(os.environ,
+                        {"GITEA_SESSION_PROFILE_LOCK": "prgs-reviewer"}):
+            rc = review_pr.main([
+                "--pr-number", "81", "--event", "APPROVE",
+            ])
+        self.assertEqual(rc, 0)
 
-        original_exists = os.path.exists
+    @patch("review_pr.api_request")
-        def conditional_exists(path):
+    @patch("review_pr.get_auth_header", return_value=FAKE_CREDS)
-            if "gitea_mutation_authority.lock" in str(path):
+    def test_cli_allowed_without_session_lock(self, _auth, mock_api):
-                return True
+        # No lock in the environment = direct operator CLI use; the wall
-            return original_exists(path)
+        # does not apply and the normal flow proceeds.
-
+        mock_api.side_effect = [FAKE_PR_DATA, {}]
-        original_open = open
+        env = {k: v for k, v in os.environ.items()
-        def conditional_open(file, *args, **kwargs):
+               if k != "GITEA_SESSION_PROFILE_LOCK"}
-            if "gitea_mutation_authority.lock" in str(file):
+        with patch.dict(os.environ, env, clear=True):
-                return io.StringIO('{"current_profile": "prgs-reviewer"}')
-            return original_open(file, *args, **kwargs)
-
-        with patch("os.path.exists", side_effect=conditional_exists), \
-             patch("builtins.open", side_effect=conditional_open):
             rc = review_pr.main([
                 "--pr-number", "81", "--event", "APPROVE",
             ])