consult

consult is an open-source MCP server, published under the MIT license by Neel Satyavolu, that lets coding agents get a second opinion from agents made by other vendors. It works through the Claude Code, Codex, Grok and Antigravity CLIs already signed in on your machine, so no API keys are needed. The latest GitHub release listed is v1.2.0.

What It Is

consult is a coding-agent collaboration layer delivered as an MCP server and a companion CLI. A host agent such as Claude Code can ask Codex to check a plan, Codex can ask Grok why a test is flaky, or any agent can put one question to several advisors at once. Each advisor answers inside the asking agent's conversation and returns a session ID for follow-up questions.

The server's instructions tell the host agent when to consult: after two failed fixes, before hard-to-reverse decisions such as migrations, before calling work done, and when being wrong is costly. Install also adds a short consult section to each agent's global instructions file, and uninstall removes it.

Reviews and live sessions

The review command sends uncommitted changes, a branch since a base ref, or a GitHub pull request to every installed advisor in parallel. Findings come back with severity, file and line, the failing scenario and a suggested fix. Reviews can be run by an agent through the review_changes tool or from the terminal with consult review.

Two optional features are off by default. Live sessions let agents list other running Claude Code, Codex and Grok sessions and ask a read-only forked copy of one, with scope set to repo, tree or machine. Session messages let an agent leave a short note for a running session. Both need macOS or Linux.

Containment and task dispatch

Advisors run headless, read-only and with no MCP servers, so they cannot edit files or call consult back. The README lists the specific flags used for each CLI. For Antigravity, consult checks the agy configuration before every call and refuses to run it unless writes, shell commands and URL fetches require approval and no MCP servers, plugins or hooks are enabled.

An optional task dispatch mode hands a self-contained job to a Codex or Grok worker in the background, which the agent can monitor or cancel. Workers are the one exception to read-only because they edit files in the working directory, so the README advises reviewing their diff.

Setup path

Run npx -y consult-mcp@latest install to register consult with every agent CLI found on your PATH. It requires Node 22 or later and at least one signed-in claude, codex or grok CLI. Each new agent session starts the latest release through npx. consult doctor checks the setup, and uninstall removes the registrations and hooks it added.