MCP

The Replicas MCP server lets AI assistants spawn, interact with, and destroy replicas (sandboxed coding agents) to complete engineering tasks. Two transport options are available:

Transport	Use Case
Stdio	MCP clients that can run local processes (Claude Desktop, Claude Code)
Streamable HTTP	MCP clients that require a remote server URL

Stdio MCP

For MCP clients that can run local processes (e.g., Claude Desktop, Claude Code):

{
  "mcpServers": {
    "replicas": {
      "command": "npx",
      "args": ["-y", "replicas-mcp"],
      "env": {
        "REPLICAS_API_KEY": "sk_replicas_..."
      }
    }
  }
}

Streamable HTTP MCP

For MCP clients that require a remote server URL:

URL: https://api.replicas.dev/v1/mcp
Authorization: Bearer sk_replicas_...

Organization admins can create a shared key under Organization → Settings → API Keys. Any member can create a personal key under Personal → API Keys. create_replica requires an environment ID. Get it from list_environments, the environment’s app URL, or replicas env list.

Tools

Tool	Description
`create_replica`	Create a workspace for an `environment_id` and send an initial message. Supports `coding_agent` (`claude`, `codex`, `cursor`, `muse`, `opencode`, `pi`), `model`, `lifecycle_policy`, `plan_mode`, `goal_mode`, and `fast_mode`.
`list_replicas`	List all replicas with optional filters (`user_id`, `source`, `status`)
`get_replica`	Get replica details with optional `include` param (`environment`, `diffs`) for rich workspace state
`send_replica_message`	Send a message to a replica. Supports `chat_id`, `coding_agent` (`claude`, `codex`, `cursor`, `muse`, `opencode`, `pi`), `model`, `plan_mode`, `goal_mode`, `fast_mode`, and `thinking_level` (low, medium, high, xhigh, max, ultra, ultracode).
`delete_replica`	Delete a replica
`list_repositories`	List available repositories
`list_repository_sets`	List available repository sets (named groups of repositories)
`list_chats`	List chats in a replica workspace
`create_chat`	Create a new chat in a replica workspace
`delete_chat`	Delete a chat from a replica workspace
`read_replica_history`	Read conversation history from a replica in pages, starting from the most recent events. Supports `chat_id`. Over Streamable HTTP, also supports `limit` (default 300 events) and `before_cursor` for older pages
`get_replica_hooks`	Get warm and start hook logs for a replica
`list_environments`	List environments with their ids, repositories, variable keys (never values), files, skills, MCP servers, plugins, and start hook
`create_automation`	Create an organization automation with a prompt, environment, and triggers

The Mothership workspace also gets its routing tools from this server, and orchestrating workspaces get their subagent tools in Multitask mode. See the API reference for full parameter details. Use ultra with Codex or Muse Code for proactive multi-agent reasoning, or ultracode with Claude Code for xhigh reasoning plus automatic dynamic workflows.

Prerequisites

Same as the Public API.

Get started

Workspaces

Coding agents

Integrations

Build and automate

Apps

Admin

Updates

Stdio MCP

Streamable HTTP MCP

Tools

Prerequisites

​Stdio MCP

​Streamable HTTP MCP

​Tools

​Prerequisites

Stdio MCP

Streamable HTTP MCP

Tools

Prerequisites