Agy Bridge

What sshahzaiib/agy-bridge does

sshahzaiib/agy-bridge lets an MCP client send heavy work to the Antigravity CLI instead of handling every file read, search, or web lookup in the calling model's context. The bridge is designed for Claude Code, but its MCP tools can be invoked by other MCP clients.

Delegated work includes analyzing large files and multi-file sets, investigating a repository's history and usage patterns, looking up documentation or current external information, and reviewing plans or code from an adversarial perspective. A general-purpose delegation tool covers tasks that do not fit those categories.

How it works

The client starts the package with npx, and the bridge invokes the authenticated agy command in the requested working directory. Each call can provide an optional cwd and model selection. The bridge checks models reported by agy models, chooses the first available model in the relevant preference chain, and falls back through other candidates when needed.

Routing is Gemini-first. The tool-specific chains select different Gemini families and tiers for analysis, search, web lookup, reviews, and general delegation; Claude Opus and GPT-OSS are appended as fallback choices when no Gemini model is available. A configured default model and then agy's own default provide further fallback behavior.

Responses include the selected model and a session identifier. follow_up uses that identifier to continue an earlier Antigravity conversation without resending its context. When a model reports quota exhaustion, the bridge stops the process, records the reset period, marks the model as temporarily unavailable, and retries on the next candidate.

Setup and configuration

The runtime requires Node.js 18 or newer, an installed and authenticated Antigravity CLI, and an MCP client such as Claude Code. Claude Code can register the server with:

claude mcp add-json -s user agy-bridge \
  '{"command":"npx","args":["-y","agy-bridge"],"timeout":600000}'

The client-side timeout should be long enough for delegated operations. The bridge also supports MCP_TOOL_TIMEOUT for clients that do not honor a per-server timeout. Its own operation budgets can be controlled globally with AGY_TIMEOUT or individually with AGY_TIMEOUT_ANALYZE_FILES, AGY_TIMEOUT_DEEP_SEARCH, AGY_TIMEOUT_WEB_LOOKUP, AGY_TIMEOUT_ADVERSARIAL_REVIEW, AGY_TIMEOUT_FOLLOW_UP, and AGY_TIMEOUT_DELEGATE. Per-tool values override the global value.

Tools and capabilities

• analyze_files handles large files, file sets spanning more than three files, logs, database dumps, generated code, and cross-file comparisons.
• deep_search performs repository-wide searches and investigates Git history through log, diff, and blame information.
• web_lookup retrieves library documentation, API references, explanations for errors, and other external or current information.
• adversarial_review asks for a second opinion on plans, designs, and code, focusing on edge cases, security concerns, flaws, and assumptions.
• follow_up continues a prior delegation using its session_id.
• delegate sends other heavy tasks directly to Antigravity with access to the supplied working directory.

All tools accept optional working-directory and model parameters. Model names are validated before execution, and responses identify the model and session used.

Limitations and notes

The Antigravity CLI must be installed and authenticated before the bridge can perform delegated work. The MCP client's tool-call deadline is separate from the bridge's own execution timeout; if the client deadline is shorter, it can stop waiting first. Cancelling a tool call terminates the Antigravity process group, and timed-out or cancelled work can be continued through the returned session when a session identifier is available.