Ask LLM

Ask LLM is an open-source MCP server suite built by Anton Lykhoyda that enables AI-to-AI collaboration — letting your primary coding agent (Claude Code, Codex CLI, Cursor, or any of 40+ MCP clients) consult a second model for independent code review, architecture critique, or plan debate. Released under the MIT License, it is available on npm under the @ask-llm organization and actively maintained on GitHub.

What It Is

Ask LLM bridges multiple large language model providers through the Model Context Protocol (MCP), so a coding agent can get a "second opinion" without leaving its workflow. The core idea is that confidence isn't correctness: a second model with no stake in the first one's answer can catch what the primary missed. The project ships as a family of MCP server packages — one per provider plus a unified orchestrator — and a host package for Claude Code, Cursor Agent, and Pi.

Provider Coverage and Model Routing

Ask LLM supports six distinct reviewer backends, each as a separate npm package or accessible through the unified @ask-llm/mcp orchestrator:

• Codex (@ask-llm/codex-mcp) — GPT-5.6 Sol with Terra fallback; strongest code reasoning
• Claude (@ask-llm/claude-mcp) — Opus with Sonnet fallback; native sessions; read-only workspace tools
• Grok (@ask-llm/grok-mcp) — Grok 4.6 via xAI API or official Grok CLI; no model fallback
• Antigravity (@ask-llm/antigravity-mcp) — Google's subscription-backed successor to Gemini CLI; gemini-3.1-pro with flash fallback
• Ollama (@ask-llm/ollama-mcp) — fully local, zero cost, offline; qwen3.8:27b default
• Gemini (@ask-llm/gemini-mcp) — 1M+ token context; enterprise-gated from 2026-06-18

The unified ask-llm tool routes per call and can fan out to all installed providers in parallel via multi-llm.

How the Request Flow Works

When a user prompts their agent (e.g., "ask codex to review src/auth.ts for security issues"), the agent calls an MCP tool, the MCP server spawns the corresponding provider CLI, and streams the answer back as structured content. Session-capable tools accept an optional sessionId for multi-turn conversations. The orchestrator also exposes a usage://current-session MCP Resource for live JSON usage snapshots, and a diagnose/doctor command for setup verification.

Claude Code Plugin and Host Package

The @ask-llm/plugin package extends Claude Code, Cursor Agent, and Pi with slash commands and automated hooks:

• /multi-review — parallel Antigravity + Codex review with a 4-phase validation pipeline
• /brainstorm — multi-LLM brainstorm with synthesis weighted toward verified findings
• /compare — side-by-side raw responses from multiple providers
• /codex-pair — opt-in continuous review hook that runs Codex against every file edit when a .codex-pair/context.md marker is present
• /fable-review, /grok-review, /ollama-review, /sol-review, /antigravity-review — provider-specific review commands

The review pipeline is described in the README as inspired by Anthropic's code-review plugin, using context gathering, prompt construction with false-positive exclusions, synthesis, and source-level validation.

Update: v1.6.17 and Gemini CLI Enterprise Gate

The latest release is v1.6.17, published 2026-07-24. The repository was last pushed 2026-08-24, indicating active development. A notable recent change documented in the README is that Google is restricting Gemini CLI to enterprise seats from 2026-06-18; the project recommends switching to ask-antigravity (the Google-sanctioned successor via Google AI Pro/Ultra) or other providers. All public MCP packages have also migrated to the @ask-llm npm organization from older package names like ask-gemini-mcp and ask-llm-mcp.

Setup Path

Prerequisites are Node.js v20+ and at least one authenticated provider CLI. The fastest install for Claude Code is:

claude mcp add --scope user ask-llm -- npx -y @ask-llm/mcp

A ping tool verifies the connection and lists detected providers; npx @ask-llm/mcp doctor diagnoses PATH, Node version, and provider CLI presence. An interactive REPL (npx @ask-llm/mcp repl) supports multi-provider sessions with live usage tracking.