feat(antigravity): support mcp_config.json generation under .agents/

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `apm install` now supports target-native MCP config generation for the `antigravity` target, writing to `.agents/mcp_config.json` (project scope) or `~/.gemini/config/mcp_config.json` (user scope). Remote SSE and HTTP servers are correctly formatted to use the `serverUrl` field required by Google Antigravity. (by @okamiconcept, #2039)
+
 ### Fixed
 
 - Sub-skill and native-skill ownership tracking now keys on the full

src/apm_cli/adapters/client/antigravity.py

@@ -52,3 +52,20 @@ def _get_config_dir(self) -> Path:
     def get_config_path(self):
         """Return the path to ``mcp_config.json`` for the active scope."""
         return str(self._get_config_dir() / "mcp_config.json")
+
+    def _format_server_config(self, server_info, env_overrides=None, runtime_vars=None):
+        """Format server info into Antigravity CLI MCP configuration.
+
+        Delegates to the parent (GeminiClientAdapter) for initial formatting,
+        then replaces any ``url`` or ``httpUrl`` key with ``serverUrl`` for
+        remote endpoints to match Antigravity's schema.
+        """
+        config = super()._format_server_config(
+            server_info, env_overrides=env_overrides, runtime_vars=runtime_vars
+        )
+        if isinstance(config, dict):
+            if "url" in config:
+                config["serverUrl"] = config.pop("url")
+            elif "httpUrl" in config:
+                config["serverUrl"] = config.pop("httpUrl")
+        return config

src/apm_cli/integration/mcp_integrator_install.py

@@ -240,6 +240,7 @@ def _discover_installed_runtimes(project_root_path, *, user_scope: bool) -> list
             "claude",
             "intellij",
             "hermes",
+            "antigravity",
         ]:
             try:
                 if not _runtime_is_present(
@@ -283,6 +284,10 @@ def _runtime_is_present(
         from apm_cli.adapters.client.intellij import _intellij_config_dir
 
         return _intellij_config_dir().is_dir()
+    if runtime_name == "antigravity":
+        if user_scope:
+            return find_runtime_binary("agy") is not None
+        return (project_root_path / ".agents").is_dir()
     if runtime_name == "hermes":
         return _hermes_runtime_opted_in()
     return manager.is_runtime_available(runtime_name)
@@ -307,6 +312,12 @@ def _discover_installed_runtimes_fallback(
     # Claude Code: directory-presence OR binary-on-PATH
     if (project_root_path / ".claude").is_dir() or find_runtime_binary("claude") is not None:
         installed_runtimes.append("claude")
+    # Antigravity: directory-presence (project-scope) OR binary-on-PATH (user-scope)
+    if user_scope:
+        if find_runtime_binary("agy") is not None:
+            installed_runtimes.append("antigravity")
+    elif (project_root_path / ".agents").is_dir():
+        installed_runtimes.append("antigravity")
     # JetBrains Copilot: user-scope config directory presence
     try:
         from apm_cli.adapters.client.intellij import _intellij_config_dir

src/apm_cli/integration/targets.py

@@ -450,6 +450,7 @@ def for_scope(self, user_scope: bool = False) -> TargetProfile | None:
     "vscode": "copilot",
     "agents": "copilot",
     "intellij": "copilot",
+    "antigravity": "antigravity",
 }
 
 

tests/integration/test_mcp_targets_gating_e2e.py

@@ -45,6 +45,21 @@ def _make_stdio_dep(name: str = "test-srv") -> MCPDependency:
     )
 
 
+def _make_remote_dep(name: str = "test-remote") -> MCPDependency:
+    """Build a synthetic remote MCP dependency that needs no network."""
+    return MCPDependency.from_dict(
+        {
+            "name": name,
+            "registry": False,
+            "transport": "http",
+            "url": "https://api.example.com/mcp/",
+            "headers": {
+                "Authorization": "Bearer TEST_TOKEN",
+            },
+        }
+    )
+
+
 def _seed_signal(project: Path, target: str) -> None:
     """Seed an on-disk signal that ``detect_signals`` recognizes."""
     if target == "copilot":
@@ -77,6 +92,10 @@ def _codex_mcp_path(project: Path) -> Path:
     return project / ".codex" / "config.toml"
 
 
+def _agents_mcp_path(project: Path) -> Path:
+    return project / ".agents" / "mcp_config.json"
+
+
 class TestMCPTargetsGatingE2E:
     def test_user_scope_claude_install_honors_claude_config_dir(self, tmp_path, monkeypatch):
         project = tmp_path / "project"
@@ -232,3 +251,44 @@ def test_greenfield_no_targets_no_signals_no_flag_writes_nothing(
             "not receive a silent copilot-vscode MCP write -- the "
             "pre-#1336 fallback is gone."
         )
+
+    def test_targets_whitelist_antigravity_allows_listed_runtimes(self, tmp_path, monkeypatch):
+        """``targets: [antigravity]`` -> antigravity MCP config IS written
+        when .agents/ project-scope directory exists.
+        """
+        project = tmp_path / "proj-whitelist-antigravity"
+        project.mkdir()
+        fake_home = tmp_path / "home"
+        fake_home.mkdir()
+        monkeypatch.setenv("HOME", str(fake_home))
+
+        # Seed the .agents directory (the required signal for project scope)
+        (project / ".agents").mkdir()
+
+        MCPIntegrator.install(
+            [
+                _make_stdio_dep("e2e-antigravity-stdio"),
+                _make_remote_dep("e2e-antigravity-remote"),
+            ],
+            project_root=project,
+            apm_config={"targets": ["antigravity"]},
+        )
+
+        assert _agents_mcp_path(project).exists(), (
+            "antigravity MCP config MUST be written when antigravity IS in targets "
+            "and .agents/ directory exists."
+        )
+        agents_data = json.loads(_agents_mcp_path(project).read_text(encoding="utf-8"))
+
+        # Verify stdio server formatting
+        stdio_srv = agents_data.get("mcpServers", {}).get("e2e-antigravity-stdio", {})
+        assert stdio_srv.get("command") == "echo"
+        assert stdio_srv.get("args") == ["mcp-targets-gate-e2e"]
+
+        # Verify remote server formatting uses serverUrl instead of url or httpUrl
+        remote_srv = agents_data.get("mcpServers", {}).get("e2e-antigravity-remote", {})
+        assert "serverUrl" in remote_srv
+        assert remote_srv["serverUrl"] == "https://api.example.com/mcp/"
+        assert "url" not in remote_srv
+        assert "httpUrl" not in remote_srv
+        assert remote_srv.get("headers", {}).get("Authorization") == "Bearer TEST_TOKEN"

tests/unit/integration/test_antigravity_target.py

@@ -267,6 +267,51 @@ def test_antigravity_mcp_writes_mcp_servers_to_dedicated_file(tmp_path: Path) ->
     assert data["mcpServers"]["demo"]["command"] == "npx"
 
 
+def test_antigravity_mcp_remote_server_uses_server_url(tmp_path: Path) -> None:
+    (tmp_path / ".agents").mkdir()
+    adapter = AntigravityClientAdapter(project_root=tmp_path, user_scope=False)
+
+    server_info = {
+        "name": "remote-demo",
+        "remotes": [
+            {
+                "url": "https://api.example.com/mcp/",
+                "transport_type": "sse",
+            }
+        ],
+    }
+    server_config = adapter._format_server_config(server_info)
+    assert "serverUrl" in server_config
+    assert server_config["serverUrl"] == "https://api.example.com/mcp/"
+    assert "url" not in server_config
+    assert "httpUrl" not in server_config
+
+
+def test_antigravity_mcp_runtime_is_detected_when_agents_dir_exists(tmp_path: Path) -> None:
+    from apm_cli.integration.mcp_integrator_install import _discover_installed_runtimes
+
+    # Without .agents, not detected
+    assert "antigravity" not in _discover_installed_runtimes(tmp_path, user_scope=False)
+
+    # With .agents, detected
+    (tmp_path / ".agents").mkdir()
+    assert "antigravity" in _discover_installed_runtimes(tmp_path, user_scope=False)
+
+
+def test_antigravity_mcp_runtime_is_detected_at_user_scope_when_agy_binary_exists(
+    monkeypatch,
+) -> None:
+    import shutil
+
+    from apm_cli.integration.mcp_integrator_install import _discover_installed_runtimes
+
+    # Mock shutil.which to find 'agy'
+    monkeypatch.setattr(shutil, "which", lambda cmd: "/usr/local/bin/agy" if cmd == "agy" else None)
+
+    # At user scope, should detect antigravity since 'agy' binary exists
+    assert "antigravity" in _discover_installed_runtimes(Path("/nonexistent"), user_scope=True)
+
+
 # ---------------------------------------------------------------------------
 # Hooks -> .agents/hooks.json in Antigravity's OWN native schema
 # ---------------------------------------------------------------------------