Chromium Coding Agents

This directory provides a centralized location for files related to AI coding agents (e.g. gemini-cli) used for development within the Chromium source tree.

The goal is to provide a scalable and organized way to share prompts and tools among developers, accommodating the various environments (Linux, Mac, Windows) and agent types in use.

Directory Structure

Prompts

Prompts are located in the prompts/ subdirectory. They are categorized as follows:

• prompts/common.GEMINI.md: Contains common GEMINI.md file that defines the agent's core behavior, available tools, and system instructions for Chromium.
• prompts/tasks/: Contains prompts for specific, self-contained tasks (e.g., “refactor this component,” “add a new feature flag”). Each task belongs in its own directory with common metadata.
• prompts/templates/: Contains reusable prompt snippets that can be included in other prompts, such as instructions for using a specific tool.

src/agents/
└── prompts/
    ├── common.GEMINI.md             (general Chromium system prompt)
    ├── tasks/
    │   └── a_complex_task/
    │       └── README.md
    │       └── prompt.md
    └── templates/
        ├── specialized-tool.md
        └── platform-specific.md

MCPs (Model Context Protocols)

MCPs are helper servers that provide a stable, tool-like interface for an AI agent to use. Instead of giving an agent broad shell access, we can provide an MCP that wraps a command-line tool or infrastructure service (like LUCI). This is safer and more reliable.

MCPs will be located in the mcp/ subdirectory.

src/agents/
└── mcp/
    ├── local_server_to_wrap_tool/
    │   ├── gemini-extension.json (MCP server should be near the code it wraps)
    │   ├── GEMINI.md
    │   └── README.md
    └── remote_server_configuration/
        ├── gemini-extension.json
        ├── GEMINI.md
        └── README.md

Contributing

Please freely add self-contained task prompts and prompt templates that match the format of the existing examples.

New MCP server configurations should be for owned and supported MCP servers and include OWNERS.

Changes to common.GEMINI.md should be done carefully as it's meant to be used broadly.