feat(box): inject box.local.env into every exec payload

src/langbot/pkg/box/service.py

@@ -124,6 +124,7 @@ class BoxService:
         self.profile = self._load_profile()
         self.custom_image = self._load_custom_image()
         self.workspace_quota_mb = self._load_workspace_quota_mb()
+        self.default_env = self._load_default_env()
         self._admission_policy = (
             require_cloud_admission_policy(_get_box_config(ap).get('admission')) if self._cloud_managed else None
         )
@@ -1394,6 +1395,10 @@ class BoxService:
     def build_spec(self, spec_payload: dict, skip_host_mount_validation: bool = False) -> BoxSpec:
         spec_payload = dict(spec_payload)
         spec_payload.setdefault('env', {})
+        if self.default_env:
+            merged_env = dict(self.default_env)
+            merged_env.update(spec_payload.get('env') or {})
+            spec_payload['env'] = merged_env
         if spec_payload.get('host_path') in (None, '') and self.default_workspace is not None:
             spec_payload['host_path'] = self.default_workspace
         if spec_payload.get('workspace_quota_mb') in (None, '') and self.workspace_quota_mb is not None:
@@ -1831,6 +1836,28 @@ class BoxService:
             raise BoxValidationError('workspace_quota_mb must be greater than or equal to 0')
         return value
 
+    def _load_default_env(self) -> dict[str, str]:
+        """Return ``box.local.env`` as operator-provided sandbox defaults.
+
+        These values are merged into every Box exec payload so sandbox commands
+        can read settings such as a service base URL. A per-call ``env`` supplied
+        by the agent or caller overrides the matching defaults. Non-dict configs
+        and non-string keys or values are ignored.
+        """
+        raw_env = self._local_config().get('env')
+        if not isinstance(raw_env, dict):
+            return {}
+
+        env: dict[str, str] = {}
+        for key, value in raw_env.items():
+            if not isinstance(key, str) or not isinstance(value, str):
+                continue
+            normalized_key = key.strip()
+            if not normalized_key:
+                continue
+            env[normalized_key] = value
+        return env
+
     def _ensure_default_workspace(self):
         if self.default_workspace is None:
             return

src/langbot/templates/config.yaml

@@ -383,6 +383,9 @@ box:
             - './data/box'
             - '/tmp'
         workspace_quota_mb: null  # Optional disk quota override (>= 0). null = profile default.
+        # Extra environment variables injected into every Box exec payload.
+        # The agent-supplied per-call env overrides matching keys. Values must be strings.
+        env: {}
     # Default nsjail cgroup memory limit for each MCP stdio server process, in MB.
     # Node.js MCP servers (npx/bunx) need more memory than Python ones because V8
     # and WebAssembly modules (e.g. undici llhttp) reserve large virtual address

tests/unit_tests/box/test_box_service.py

@@ -416,6 +416,56 @@ def test_separated_box_runtime_allows_box_owned_missing_host_path(tmp_path):
     assert not (host_root / 'default').exists()
 
 
+def test_box_build_spec_injects_local_default_env():
+    logger = Mock()
+    app = make_app(logger)
+    app.instance_config.data['box']['local']['env'] = {'JENKINS_BASE_URL': 'https://jenkins.example.com'}
+    service = BoxService(app, client=Mock())
+
+    spec = service.build_spec({'cmd': 'echo hi', 'session_id': 'default-env'})
+
+    assert spec.env == {'JENKINS_BASE_URL': 'https://jenkins.example.com'}
+
+
+def test_box_build_spec_per_call_env_overrides_local_default():
+    logger = Mock()
+    app = make_app(logger)
+    app.instance_config.data['box']['local']['env'] = {
+        'JENKINS_BASE_URL': 'https://default.example.com',
+        'KEEP_ME': 'yes',
+    }
+    service = BoxService(app, client=Mock())
+
+    spec = service.build_spec(
+        {'cmd': 'echo hi', 'session_id': 'override-env', 'env': {'JENKINS_BASE_URL': 'https://override.example.com'}}
+    )
+
+    assert spec.env == {'JENKINS_BASE_URL': 'https://override.example.com', 'KEEP_ME': 'yes'}
+
+
+def test_box_build_spec_ignores_invalid_local_env_entries():
+    logger = Mock()
+    app = make_app(logger)
+    app.instance_config.data['box']['local']['env'] = {
+        'OK': 'value',
+        '': 'empty-key',
+        '   ': 'blank-key',
+        'BAD_VALUE': 123,
+        3: 'non-string-key',
+    }
+    service = BoxService(app, client=Mock())
+
+    spec = service.build_spec({'cmd': 'echo hi', 'session_id': 'invalid-env'})
+
+    assert spec.env == {'OK': 'value'}
+
+    app.instance_config.data['box']['local']['env'] = 'not-a-dict'
+    service = BoxService(app, client=Mock())
+    spec = service.build_spec({'cmd': 'echo hi', 'session_id': 'non-dict-env'})
+
+    assert spec.env == {}
+
+
 @pytest.mark.asyncio
 async def test_box_service_get_sessions_delegates_to_client():
     client = Mock()