Ask your agent.
See it in Crabrix.

A useful pair of hands, right where you work.

Code arrives. Your tools stay local.

These Simulator captures come from a four-participant check: the MCP bridge, a browser and two Crabrix apps. Each app ran its own compiler and debugger.

Clearer when something goes wrong.

In the Playground, choose Connect AI to get the setup for your client and copy a task with its room link. Your agent appears in the room when it joins.

From your agent to a shared editor.

1. 01

   Install it once for your client

   Choose the one way that fits your client. You do not need both. A Crabrix account is not required.

   Claude Code

   The plugin registers the MCP server and adds a handoff skill. Do not add a second server by hand.

   /plugin marketplace add sergii-ziborov/crabrix-sdk
   /plugin install crabrix@crabrix

   Another client that runs local MCP servers

   Needs Node.js 22 or newer. Add this entry to the client’s MCP configuration and restart it. This is a documented configuration and has not been tested in every client.

   {
     "mcpServers": {
       "crabrix": {
         "command": "npx",
         "args": ["-y", "crabrix@0.3.5"]
       }
     }
   }

   A client with only remote MCP

   Not supported yet. Crabrix has no remote MCP endpoint, so use a client that can start a local server.

   Still using crabrix-playground-mcp?

   It is the older name of this bridge. Remove that server and add one of the above, so the two do not join a room as separate participants. Existing room links keep working.

   Check your setup with npx -y crabrix@0.3.5 doctor. Machine-readable setup: bootstrap.json.

2. 03

   Share from Crabrix or the web

   Ask your connected agent to create a Crabrix Playground and return its temporary link, or open the web Playground and choose Share. Copy the entire link, including everything after #.

   Give that link to Claude only when you want to grant its MCP host and model access to this room’s source. View-only links allow reading; editable links allow source changes.

3. 04

   Give your agent a task. Open the link.

   Connect to this Crabrix Playground: [paste your private link]. Read the current source, add a Fibonacci function, and highlight the part you changed. Preserve everyone else’s work.

   The MCP bridge appears as Agent · Crabrix. Watch its code and selection in the browser or optional app. Use Run or Debug yourself, or ask Claude to discover local clients. In Share on the selected client, compare its device/controller keys, choose operations and press Allow selected operations. Save a local copy before expiry.

Use Crabrix in your own agent.

No phone app is required. All three APIs use the same local protocol core and require Node.js 22+. Rust and Go embed the bridge; they do not need a global npm install. Code is MIT; brand artwork and app screenshots retain separate terms.

npm install crabrix@0.3.5

cargo add crabrix@0.3.5

go get github.com/sergii-ziborov/crabrix-sdk/go/crabrix@v0.3.5

import { Crabrix } from "crabrix";

const agent = new Crabrix({ name: "Review agent" });
try {
  await agent.create({ name: "Rust exercise", lifetimeMinutes: 60 });
  const file = await agent.read("main.rs");
  await agent.apply({
    expectedRevision: file.revision,
    changes: [{ path: file.path, text: file.text + "// reviewed\n" }],
  });
  const handoff = await agent.share("edit");
  // Deliver handoff.link only to an intended recipient.
  // Show handoff.expiresAt alongside your share action.
} finally {
  agent.close();
}

Public GitHub repository ↗ · SDK integration walkthrough · Run a shared Rust interview · Two agents: development, review and learning

One participant runs. Everyone can see the result.

The relay carries encrypted messages only. Code, comments and program output remain untrusted project data. No arbitrary watch expressions, implicit toolchain/package downloads, private files, stdin or host environment enter the MCP execution profile.