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Code Relay

Official registry Developer tools

Branch-scoped runbooks, remote checkpoints, and auditable verification receipts.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package code-relay-mcp
Claude Code 
claude mcp add code-relay -- npx -y code-relay-mcp@3.1.0
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "code-relay": {
            "command": "npx",
            "args": [
                "-y",
                "code-relay-mcp@3.1.0"
            ]
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Code Relay
  2. Build. Prove. Relay.
  3. When Relay is useful
  4. What Relay provides
  5. Quick start
  6. MCP server details
  7. How it works
  8. Documentation
  9. License

Code Relay

English · Chinese

Build. Prove. Relay.

Code Relay lets your coding agent develop on one machine and prove the result on another.

Relay is an MCP-based coding-agent integration for cross-machine development and verification. AI on the Dev Host implements the request; the Target Host runs the real validation; a structured receipt comes back to guide the next repair iteration. It works with Codex, Claude Code, Cursor, VS Code, and other MCP-capable coding agents.

When Relay is useful

  • Different environments — develop on Windows or macOS, verify on Linux, a private network, or a production-like host.
  • Special hardware — send model code to a CUDA/GPU machine, or verify a camera, serial device, or sensor where it is connected.
  • Real integrations — exercise payment callbacks, queues, databases, browsers, or internal services that cannot be reproduced locally.
  • AI-driven iteration — return concrete expected/actual results so the coding agent can repair, republish, and retry.

What Relay provides

  • Branch-scoped project binding and short-lived join links.
  • Exact source-commit verification in an isolated worktree.
  • Checkpoint execution through a code-relay-checkpoint GitHub Actions self-hosted runner.
  • Safe, allowlisted validation commands with bounded output and timeouts.
  • Structured receipt.json and human-readable receipts for passed, failed, and blocked runs.

Quick start

AI client installation

Let your coding agent read and follow the instructions:

https://raw.githubusercontent.com/zarcherlot/code-relay/main/install.md
npm fallback
npx -y code-relay-mcp@latest install --client codex

Replace codex with claude-code, cursor, vscode, or generic as needed.

MCP server details

Code Relay is a local MCP server that communicates over stdio. The npm package starts the server with:

npx -y code-relay-mcp@3.1.0

The server implements the MCP JSON-RPC surface directly in Go (without a third-party MCP SDK). It supports initialize, ping, tools/list, and tools/call, and exposes these tools:

ToolPurpose
bind_projectBind a repository and branch to a relay role.
create_checkpoint_inviteCreate a short-lived checkpoint join link.
join_checkpointJoin a branch-scoped checkpoint subscription.
watcher_statusRead local watcher state.
stop_watcherStop the local watcher.
doctorRun non-mutating local health checks.
publish_runbookValidate and publish a runbook.
statusRead runbook and receipt status.
fetch_receiptLoad and validate a runbook receipt.
analyzeAnalyze a receipt and determine the next state.

The implementation and transport loop are in internal/relay/mcp.go.

How it works

the Dev Host sends a repository- and branch-bound runbook through Relay; the Target Host checks the exact source commit in its real environment and returns a Receipt recording the Checkpoint result.

Every runbook is bound to a repository, branch, and source commit. The Target Host acts as the Checkpoint, and the resulting receipt records passed, failed, or blocked verification for the next iteration.

Documentation

License

Code Relay is released under the MIT License.

Frequently asked questions

What is Code Relay?

Branch-scoped runbooks, remote checkpoints, and auditable verification receipts.

How do I install Code Relay?

It runs on your machine. In Claude Code: claude mcp add code-relay -- npx -y code-relay-mcp@3.1.0. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Code Relay need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Code Relay open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Code Relay?

It is published by zarcherlot. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.