diff --git a/src/main.py b/src/main.py
index 5ba863a..c9e839b 100644
--- a/src/main.py
+++ b/src/main.py
@@ -687,6 +687,8 @@ def main(argv: list[str] | None = None) -> int:
     if args.command == 'exec-command':
         result = execute_command(args.name, args.prompt)
         # #168: JSON envelope with typed not-found error
+        # #181: envelope exit_code must match process exit code
+        exit_code = 0 if result.handled else 1
         if args.output_format == 'json':
             import json
             if not result.handled:
@@ -708,13 +710,15 @@ def main(argv: list[str] | None = None) -> int:
                     'handled': True,
                     'message': result.message,
                 }
-            print(json.dumps(wrap_json_envelope(envelope, args.command)))
+            print(json.dumps(wrap_json_envelope(envelope, args.command, exit_code=exit_code)))
         else:
             print(result.message)
-        return 0 if result.handled else 1
+        return exit_code
     if args.command == 'exec-tool':
         result = execute_tool(args.name, args.payload)
         # #168: JSON envelope with typed not-found error
+        # #181: envelope exit_code must match process exit code
+        exit_code = 0 if result.handled else 1
         if args.output_format == 'json':
             import json
             if not result.handled:
@@ -736,10 +740,10 @@ def main(argv: list[str] | None = None) -> int:
                     'handled': True,
                     'message': result.message,
                 }
-            print(json.dumps(wrap_json_envelope(envelope, args.command)))
+            print(json.dumps(wrap_json_envelope(envelope, args.command, exit_code=exit_code)))
         else:
             print(result.message)
-        return 0 if result.handled else 1
+        return exit_code
     parser.error(f'unknown command: {args.command}')
     return 2
 
diff --git a/tests/test_exec_route_bootstrap_output_format.py b/tests/test_exec_route_bootstrap_output_format.py
index 98010a5..899e3c0 100644
--- a/tests/test_exec_route_bootstrap_output_format.py
+++ b/tests/test_exec_route_bootstrap_output_format.py
@@ -202,3 +202,78 @@ class TestFamilyWideJsonParity:
             )
             # Output should not be JSON-shaped (no leading {)
             assert not result.stdout.strip().startswith('{')
+
+
+class TestEnvelopeExitCodeMatchesProcessExit:
+    """#181: Envelope exit_code field must match actual process exit code.
+    
+    Regression test for the protocol violation where exec-command/exec-tool
+    not-found cases returned exit code 1 from the process but emitted
+    envelopes with exit_code: 0 (default wrap_json_envelope). Claws reading
+    the envelope would misclassify failures as successes.
+    
+    Contract (from ERROR_HANDLING.md):
+    - Exit code 0 = success
+    - Exit code 1 = error/not-found
+    - Envelope MUST reflect process exit
+    """
+
+    def test_exec_command_not_found_envelope_exit_matches(self) -> None:
+        """exec-command 'unknown-name' must have exit_code=1 in envelope."""
+        result = _run(['exec-command', 'nonexistent-cmd-name', 'test-prompt', '--output-format', 'json'])
+        assert result.returncode == 1, f'process exit should be 1, got {result.returncode}'
+        envelope = json.loads(result.stdout)
+        assert envelope['exit_code'] == 1, (
+            f'envelope.exit_code mismatch: process=1, envelope={envelope["exit_code"]}'
+        )
+        assert envelope['handled'] is False
+        assert envelope['error']['kind'] == 'command_not_found'
+
+    def test_exec_tool_not_found_envelope_exit_matches(self) -> None:
+        """exec-tool 'unknown-tool' must have exit_code=1 in envelope."""
+        result = _run(['exec-tool', 'nonexistent-tool-name', '{}', '--output-format', 'json'])
+        assert result.returncode == 1, f'process exit should be 1, got {result.returncode}'
+        envelope = json.loads(result.stdout)
+        assert envelope['exit_code'] == 1, (
+            f'envelope.exit_code mismatch: process=1, envelope={envelope["exit_code"]}'
+        )
+        assert envelope['handled'] is False
+        assert envelope['error']['kind'] == 'tool_not_found'
+
+    def test_all_commands_exit_code_invariant(self) -> None:
+        """Audit: for every clawable command, envelope.exit_code == process exit.
+        
+        This is a stronger invariant than 'emits JSON'. Claws dispatching on
+        the envelope's exit_code field must get the truth, not a lie.
+        """
+        # Sample cases known to return non-zero
+        cases = [
+            # command, expected_exit, justification
+            (['show-command', 'nonexistent-abc'], 1, 'not-found inventory lookup'),
+            (['show-tool', 'nonexistent-xyz'], 1, 'not-found inventory lookup'),
+            (['exec-command', 'nonexistent-1', 'test'], 1, 'not-found execution'),
+            (['exec-tool', 'nonexistent-2', '{}'], 1, 'not-found execution'),
+        ]
+        mismatches = []
+        for args, expected_exit, reason in cases:
+            result = _run([*args, '--output-format', 'json'])
+            if result.returncode != expected_exit:
+                mismatches.append(
+                    f'{args}: expected process exit {expected_exit} ({reason}), '
+                    f'got {result.returncode}'
+                )
+                continue
+            try:
+                envelope = json.loads(result.stdout)
+            except json.JSONDecodeError as e:
+                mismatches.append(f'{args}: JSON parse failed: {e}')
+                continue
+            if envelope.get('exit_code') != result.returncode:
+                mismatches.append(
+                    f'{args}: envelope.exit_code={envelope.get("exit_code")} '
+                    f'!= process exit={result.returncode} ({reason})'
+                )
+        assert not mismatches, (
+            'Envelope exit_code must match process exit code:\n' + 
+            '\n'.join(mismatches)
+        )