feat: Add antigravity support

docs/installation.md

@@ -21,7 +21,7 @@ To undo:
 semble uninstall
 ```
 
-Supported agents: Claude Code, Cursor, Gemini CLI, Kiro, OpenCode, GitHub Copilot, Codex, VS Code, Windsurf, Zed, Reasonix, Pi, and Command Code.
+Supported agents: Claude Code, Cursor, Gemini CLI, Kiro, OpenCode, GitHub Copilot, Codex, VS Code, Windsurf, Zed, Reasonix, Pi, Command Code, and Antigravity.
 
 > **Pi prerequisite:** Pi requires the MCP extension to be installed before semble can connect. Run `pi install npm:pi-mcp-extension` once, then `semble install`.
 
@@ -242,6 +242,24 @@ Then add to `~/.pi/agent/mcp.json`:
 
 </details>
 
+<details>
+<summary>Antigravity</summary>
+
+Add to `~/.gemini/config/mcp_config.json`:
+
+```json
+{
+  "mcpServers": {
+    "semble": {
+      "command": "uvx",
+      "args": ["--from", "semble[mcp]", "semble"]
+    }
+  }
+}
+```
+
+</details>
+
 <details>
 <summary>Command Code</summary>
 
@@ -318,7 +336,7 @@ If `semble` is not on `$PATH`, use `uvx --from "semble[mcp]" semble` in its plac
 
 ### Sub-agent
 
-For harnesses that support sub-agents (Claude Code, Cursor, Gemini CLI, Kiro, OpenCode, GitHub Copilot, Reasonix, Pi, Command Code), you can install a dedicated `semble-search` sub-agent. Copy the appropriate file from [`src/semble/agents/`](../src/semble/agents/) to your agent's agents directory:
+For harnesses that support sub-agents (Claude Code, Cursor, Gemini CLI, Kiro, OpenCode, GitHub Copilot, Reasonix, Pi, Command Code, Antigravity), you can install a dedicated `semble-search` sub-agent. Copy the appropriate file from [`src/semble/agents/`](../src/semble/agents/) to your agent's agents directory:
 
 > **Pi prerequisite:** Pi sub-agents require the Pi agents extension. Run `pi install npm:pi-agents` once before installing.
 
@@ -333,3 +351,4 @@ For harnesses that support sub-agents (Claude Code, Cursor, Gemini CLI, Kiro, Op
 | Reasonix | `reasonix.md` | `~/.reasonix/skills/semble-search.md` |
 | Pi | `pi.md` | `~/.pi/agents/semble-search.md` |
 | Command Code | `commandcode.md` | `~/.commandcode/agents/semble-search.md` |
+| Antigravity | `antigravity.md` | `~/.gemini/config/skills/semble-search/SKILL.md` |

src/semble/agents/antigravity.md

@@ -0,0 +1,43 @@
+---
+name: semble-search
+description: Code search agent for exploring any codebase. Use for finding code by intent, locating implementations, understanding how something works, or discovering related code. Prefer over run_shell_command/read_file for any semantic or exploratory question.
+tools:
+  - run_shell_command
+  - read_file
+---
+
+Use `semble search` to find code by describing what it does or naming a symbol/identifier, instead of grep:
+
+```bash
+semble search "authentication flow" ./my-project
+semble search "save_pretrained" ./my-project
+semble search "save model to disk" ./my-project --top-k 10
+```
+
+Results are cached automatically on first run and invalidated when files change.
+
+Use `--content docs` to search documentation and prose, `--content config` for config files (yaml, toml, etc.), or `--content all` to search code, docs, and config:
+
+```bash
+semble search "deployment guide" ./my-project --content docs
+semble search "database host port" ./my-project --content config
+semble search "authentication" ./my-project --content all
+```
+
+Use `semble find-related` to discover code similar to a known location (pass `file_path` and `line` from a prior search result):
+
+```bash
+semble find-related src/auth.py 42 ./my-project
+```
+
+`path` defaults to the current directory when omitted; git URLs are accepted.
+
+If `semble` is not on `$PATH`, use `uvx --from "semble[mcp]" semble` in its place.
+
+### Workflow
+
+1. Start with `semble search` to find relevant chunks. The index is built and cached automatically.
+2. Use `--content docs` for documentation, `--content config` for config files, or `--content all` for everything.
+3. Inspect full files only when the returned chunk does not give enough context.
+4. Optionally use `semble find-related` with a promising result's `file_path` and `line` to discover related implementations.
+5. Use grep only when you need exhaustive literal matches or quick confirmation of an exact string.

src/semble/installer/agents.py

@@ -245,6 +245,15 @@ def _vscode_mcp_path() -> Path:
         instructions_path=_HOME / ".commandcode" / "AGENTS.md",
         subagent_path=_HOME / ".commandcode" / "agents" / "semble-search.md",
     ),
+    AgentTarget(
+        id="antigravity",
+        display_name="Antigravity",
+        binary="agy",
+        config_dir=_HOME / ".gemini" / "antigravity-cli",
+        mcp=McpConfig(_HOME / ".gemini" / "config" / "mcp_config.json", "mcpServers", _STDIO_SERVER_CONFIG),
+        instructions_path=_HOME / ".gemini" / "GEMINI.md",
+        subagent_path=_HOME / ".gemini" / "config" / "skills" / "semble-search" / "SKILL.md",
+    ),
 ]
 
 

src/semble/installer/installer.py

@@ -184,7 +184,7 @@ def run(mode: Mode) -> None:
 
     agent_items = [
         (f"{a.display_name}{'  (detected)' if (detected := is_detected(a)) else ''}", a, detected and install)
-        for a in AGENTS
+        for a in sorted(AGENTS, key=lambda a: not is_detected(a))
     ]
     chosen_agents = _checkbox(
         f"Select agents to {'configure' if install else 'remove configuration from'}:", agent_items

tests/test_installer.py

@@ -132,6 +132,7 @@ def test_merge_mcp_errors(claude_agent, content):
         ("reasonix", "mcpServers"),
         ("pi", "mcpServers"),
         ("commandcode", "mcpServers"),
+        ("antigravity", "mcpServers"),
     ],
 )
 def test_merge_mcp_writes_under_agent_key(tmp_path, agent_id, key):