antigravity-companion: Instructions file for Codex

AGENTS.md

Guidance for coding agents (and humans) working on this repository.

What this is

A JetBrains plugin that bridges the Antigravity CLI (agy) with IntelliJ-based IDEs (IntelliJ IDEA, PhpStorm, WebStorm, PyCharm, GoLand, RustRover, etc. — anything 2023.2+) through the Model Context Protocol (MCP).

• The plugin runs a local TCP MCP server inside the IDE process.
• A tiny pure-Java stdio↔TCP relay (StdioBridge) is invoked from a per-project script that the plugin generates.
• The plugin merges itself into ~/.gemini/config/mcp_config.json so agy discovers it automatically.
• Four tools are exposed: ide_get_active_editor, ide_get_open_files, ide_get_diagnostics, ide_open_file.

Plugin id: dev.matasar.antigravity-companion. License: MIT. End-user docs are in README.md.

Repository layout

src/main/
├── java/dev/matasar/antigravity/bridge/
│   └── StdioBridge.java                            ← pure-Java stdio↔TCP relay
└── kotlin/dev/matasar/antigravity/
    ├── action/StartSessionAction.kt                ← toolbar button
    ├── service/AntigravityCompanionService.kt      ← MCP server + tool implementations
    ├── settings/AntigravitySettings.kt             ← persistent app-level state (agy path)
    ├── settings/AntigravitySettingsConfigurable.kt ← Settings → Tools → Antigravity CLI Companion
    └── startup/AntigravityStartupActivity.kt       ← eager-init the service on project open
src/main/resources/
├── META-INF/plugin.xml                             ← manifest, services, actions, change notes
└── icons/, pluginIcon.svg                          ← toolbar + plugin icons
build.gradle.kts, gradle.properties, settings.gradle.kts
LICENSE  README.md  AGENTS.md

There is intentionally no agy-companion/ Go subproject, no EditorContextListener, no DiffViewerHandler, no ToolWindowFactory, no Ktor. If you find yourself adding any of these, stop and re-read the principles below.