agy-acp

An Agent Client Protocol (ACP) stdio adapter for Google Antigravity CLI (agy). It bridges agy into any ACP-compatible host like Zed, enabling you to use Gemini models through agy inside Zed's Agent Panel.

Features

• Real-Time Streaming: Directly streams NDJSON events from agy --output-format stream-json to deliver fast, incremental text updates.
• Thinking / Thought Streaming: Streams model reasoning blocks as ACP thought updates, allowing compatible hosts to render the model's thought process in real time.
• Rich Tool Execution: Maps agy tool operations (read, edit, delete, move, search, execute, fetch, etc.) into structured ACP tool calls with target file paths, line ranges, and formatted outputs (such as directory listings and grep search results).
• Session Cancellation: Handles session/cancel by cleanly aborting in-flight prompts and terminating the underlying agy subprocess.
• Dynamic Model Selection: Automatically queries models via agy models on startup and exposes them as ACP configuration options. Supports both session/set_model and session/setConfigOption.
• Session Persistence & Resume: Saves conversation mappings to disk with atomic writes and file locking, allowing sessions to resume seamlessly across restarts.
• Narration Filtering: Provides a --skip-naration CLI flag to filter out leading narrative chatter (e.g., "I will...") before model actions.

How It Works

agy-acp speaks JSON-RPC over stdin/stdout (the ACP transport). When a host sends a prompt, agy-acp spawns agy in stream-json mode, streams the output incrementally back via session/update notifications, and binds the conversation_id so subsequent turns or resumed sessions retain context.

Zed (ACP host)  <--stdin/stdout JSON-RPC-->  agy-acp  <--subprocess-->  agy  <--API-->  Gemini

Prerequisites

• Rust (1.70+) with Cargo
• agy installed and in your PATH — install from google-antigravity/antigravity-cli releases
• Authentication — either set GEMINI_API_KEY or configure auth via ~/.gemini/antigravity-cli/settings.json

Build & Install

cargo build --release

The binary is generated at target/release/agy-acp. Copy it to a directory in your PATH:

cp target/release/agy-acp /usr/local/bin/

Use with Zed

Add agy-acp as a custom agent server in your Zed settings (~/.config/zed/settings.json):

{
  "agent_servers": {
    "agy": {
      "type": "custom",
      "command": "agy-acp",
      "args": [],
      "env": {
        "AGY_EXTRA_ARGS": "--dangerously-skip-permissions"
      }
    }
  }
}

Important

Tool Execution & Permissions: Antigravity CLI does not natively support the ACP protocol yet, meaning interactive permission prompts from agy cannot be answered through ACP hosts. You must set AGY_EXTRA_ARGS="--dangerously-skip-permissions" in your environment so agy auto-approves tool permission requests, enabling tools (file editing, command execution, searching, etc.) to run properly.

Then open the Agent Panel in Zed (Cmd-? on macOS, Ctrl-? on Linux), select agy from the agent dropdown, and start chatting.

Filtering Narration

To suppress leading narrative chatter from the model, pass --skip-naration in the arguments:

{
  "agent_servers": {
    "agy": {
      "type": "custom",
      "command": "agy-acp",
      "args": ["--skip-naration"],
      "env": {}
    }
  }
}

Passing Extra Arguments

Set the AGY_EXTRA_ARGS environment variable to pass additional arguments to every agy invocation:

{
  "agent_servers": {
    "agy": {
      "type": "custom",
      "command": "agy-acp",
      "args": [],
      "env": {
        "AGY_EXTRA_ARGS": "--some-flag value"
      }
    }
  }
}

Configuration & Environment

Setting / Variable	Description
--skip-naration	CLI flag to filter out leading narrative preamble messages
GEMINI_API_KEY	API key for Gemini (passed through to agy)
AGY_EXTRA_ARGS	Space-separated extra args passed to every agy invocation

Session Persistence

Sessions are persisted to ~/.openab/agy-acp/sessions.json. When you resume a session in Zed, agy-acp restores the conversation binding and continues it with agy --conversation <id>. State persistence uses atomic write-to-temp-and-rename under an exclusive file lock to avoid data corruption.

Debugging

To inspect the JSON-RPC messages between Zed and agy-acp, run dev: open acp logs from Zed's Command Palette.

License

MIT