agy-bridge
Coding · tested 2026-08-18 · re-test due 2026-11-16 · by the Hlido desk, not the vendor
In short: A small, unusually well-engineered MCP bridge that lets Claude Code offload token-heavy grunt work to Google's Antigravity CLI — high craft, honest about its own failure modes, but a niche tool for a specific two-CLI setup.
Quick answer
agy-bridge scores 66/100 (FADING) on Hlido’s independent, hands-on test (reviewed 2026-08-18). FADING (66) — a deliberately narrow score for a deliberately narrow tool.
agy-bridge does one narrow thing and does it with more engineering discipline than most products ten times its size. The problem is concrete: Claude Code burns its context window reading raw material — a 3,000-line log, a year of git history — when what you want is the synthesized answer. agy-bridge is an MCP server (on npm, zero-install via npx) that lets Claude Code delegate that heavy reading to Google's Antigravity CLI (agy), which has its own model quota and local file access; only the summary comes back. What lifts it above a weekend hack is the thinking on display in the author's writeup. Rather than one generic 'ask Gemini' tool it exposes six purpose-built tools (analyze_files, deep_search, web_lookup, adversarial_review, follow_up, delegate), because tool descriptions are how the calling model decides when to delegate — a genuinely non-obvious insight. It stays stateless while offering session continuity by reading agy's own conversation cache. Its model routing degrades gracefully because preview-CLI model names change weekly. Most tellingly, v0.2.0 added AGY_ON_FAILURE=strict after the author noticed the worst failure was 'success theater' — a silent fallback where Claude quietly did the heavy work itself, recreating the exact problem the tool exists to solve — and concluded that instructing the calling model what to do on failure is part of an MCP tool's contract. Output is capped to protect the context window; 35 unit tests run without agy installed. The honest limits are inherent to what it is: it requires both Claude Code AND the Antigravity CLI installed, it is a solo project at v0.2, single-purpose, and the only surface we could review is the author's own blog post — no independent adoption or reliability signal. As a piece of craft and a model of how to write an MCP tool, it punches far above its scope; as a product, it is a sharp niche utility.
Why FADING
FADING (66) — a deliberately narrow score for a deliberately narrow tool. The engineering craft is high (six purpose-built tools with model-aware descriptions, stateless session continuity, graceful model routing, a strict fail-mode that closes the 'silent fallback' hole, 35 CLI-free unit tests) and the design reasoning is exemplary. It sits below STEADY because it is single-purpose and setup-dependent (needs both Claude Code and Google's Antigravity CLI), a solo project at v0.2, and the only reviewable surface is the author's blog post — no independent adoption, reliability or usage evidence.
What it does well
- Offloads token-heavy reading (large logs, git archaeology) from Claude Code to agy, returning only the synthesized answer
- Exposes six purpose-built tools whose descriptions give the calling model concrete triggers to delegate — not one generic tool
- Stays stateless while offering session continuity by reading agy's own conversation cache and returning a follow-up ID
- Routes each tool through a graceful model-preference chain, so churning preview-CLI model names don't break it
- Fails loudly by design: AGY_ON_FAILURE=strict stops Claude from silently doing the heavy work itself
- Caps output to protect the very context window it exists to save; 35 unit tests run with no agy install or network
What it fails at
- Requires both Claude Code and Google's Antigravity CLI (agy) installed — a narrow two-tool prerequisite
- Single-purpose delegation bridge; not a general-purpose agent capability
- Solo project at v0.2 with no independent adoption, reliability or usage evidence on the surface
- The only reviewable surface is the author's own blog post — no product site, docs portal or third-party validation
- Value depends on agy's Gemini quota and behaviour, an external preview CLI outside the bridge's control
Best for
- Developers already running Claude Code alongside Google's Antigravity CLI who want to conserve Claude's context window
- Workflows with recurring token-heavy tasks — large-file analysis, repo-wide git archaeology, adversarial code review
- Engineers who value a delegation tool that fails loudly rather than silently reverting to expensive local work
- Anyone studying how to design MCP tools well — the writeup is a strong reference
Not recommended for
- Users who don't run Google's Antigravity CLI (the bridge has nothing to delegate to)
- Teams needing a supported, multi-contributor product with reliability guarantees
- General agent tasks beyond offloading heavy reading/analysis
- Buyers who require documentation and adoption evidence beyond an author blog post
Related agents
Agent relevance
CLI MCP Behavioral-testable
Agentic-Commerce Readiness 50/100 · INTEGRABLE
Independent readiness for agent delegation & transaction. How it’s scored · check live
First-class MCP for Claude Code: add agy-bridge to mcpServers (command npx, args -y agy-bridge) and Claude Code gains six delegation tools. It is agent-facing by construction — a bridge one agent (Claude Code) calls to route heavy work to another CLI (agy/Gemini). Requires the Antigravity CLI installed locally to function.
Agent-friendly score: 7/10
Score over time
The longitudinal record — every point is the score as published on that date. Raw series.
Evidence
- MCP server on npm (npx -y agy-bridge) delegating heavy work from Claude Code to agy/Gemini — source (2026-08-18) verified
- Six purpose-built tools with per-tool model routing chains — source (2026-08-18) verified
- AGY_ON_FAILURE=strict prevents silent local fallback; output capped; 35 unit tests — source (2026-08-18) verified
- Independent adoption or reliability evidence beyond the author's blog — source (2026-08-18)