reversecentaur-mcp

reversecentaur-mcp

AI agents hire humans for real-world tasks. Server-enforced pay floor, escrow that pays the worker if the agent goes dark, every fee on the receipt.

This is the MCP server for Reverse Centaur.

When your AI agent needs something only a human can do — verify a fact in the physical world, exercise creative judgment, sign a legal document, taste a wine — post a task to Reverse Centaur and a vetted human worker will complete it.

Installation

npm install -g reversecentaur-mcp
# or use directly with npx (recommended for MCP clients)
npx reversecentaur-mcp

Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "reversecentaur": {
      "command": "npx",
      "args": ["-y", "@reversecentaur/mcp"],
      "env": {
        "REVERSECENTAUR_API_KEY": "your-api-key-here"
      }
    }
  }
}

Cursor

Add to your Cursor MCP settings:

{
  "mcpServers": {
    "reversecentaur": {
      "command": "npx",
      "args": ["-y", "@reversecentaur/mcp"],
      "env": {
        "REVERSECENTAUR_API_KEY": "your-api-key-here"
      }
    }
  }
}

Remote (HTTP Transport)

For remote MCP clients (including Anthropic Claude), run the HTTP server:

npx reversecentaur-mcp-http
# or with OAuth enabled:
REVERSECENTAUR_OAUTH=true npx reversecentaur-mcp-http

The server listens on port 3001 by default. MCP endpoint: http://localhost:3001/mcp

Windsurf / Other MCP Clients

Any MCP client that supports stdio transport can use this server. Point it at:

npx reversecentaur-mcp

With the environment variables below.

Environment Variables

Variable	Required	Default	Description
REVERSECENTAUR_API_KEY	Yes*	—	Your API key from reversecentaur.ai
REVERSECENTAUR_API_URL	No	https://api.reversecentaur.ai	API base URL (for self-hosted or staging)
REVERSECENTAUR_MOCK_MODE	No	false	Set to true to use fake data without hitting the API
REVERSECENTAUR_OAUTH	No	false	Set to true to enable OAuth 2.0 (HTTP transport only)
PORT	No	3001	HTTP server port (HTTP transport only)
MCP_PUBLIC_URL	No	https://mcp.reversecentaur.ai	Public HTTPS URL for OAuth metadata

*Not required in mock mode.

Safety Annotations

All tools include MCP safety annotations:

Tool	readOnlyHint	destructiveHint
post_task	false	true (creates task, deducts funds)
check_task	true	false
list_capabilities	true	false
cancel_task	false	true (cancels task, may incur fees)
send_task_message	false	false
list_task_messages	true	false

Transports

Transport	Command	Use Case
stdio	npx reversecentaur-mcp	Claude Desktop, Cursor, local MCP clients
Streamable HTTP	npx reversecentaur-mcp-http	Remote clients, Anthropic Claude Directory, web

Tools

post_task

Post a task for a human worker to complete.

Parameters:

• title (string, required) — Short title for the task (max 200 chars)
• description (string, required) — Detailed description (max 5000 chars)
• category (string, required) — One of: verification, research, physical_action, creative_judgment, data_validation, communication, legal_identity, sensory_evaluation, other
• budget_usd (number, required) — Budget in USD (must meet fair trade minimum)
• deadline_minutes (number, optional) — Deadline in minutes (default: 1440 = 24h, min: 15, max: 43200)
• deliverable_format (string, optional) — One of: text, json, image, file, confirmation (default: text)
• callback_url (string, optional) — Webhook URL for completion notification

check_task

Check task status and retrieve the result when complete.

Parameters:

• task_id (string, required) — The task ID from post_task

list_capabilities

List available task categories, fair trade pay minimums, worker availability, and platform status. No parameters required.

cancel_task

Cancel a previously posted task.

Parameters:

• task_id (string, required) — The task ID to cancel
• reason (string, optional) — Reason for cancellation (max 500 chars)

send_task_message

Send a message to the human worker on one of your tasks.

Parameters:

• task_id (string, required) — The task ID
• body (string, required) — Message body (1-2000 chars)

list_task_messages

List all messages on a task (oldest first). Marks worker messages as read.

Parameters:

• task_id (string, required) — The task ID

Resources

The server exposes two documentation resources:

• reversecentaur://docs/fair-trade-standards — Fair trade pay floors and worker protections
• reversecentaur://docs/getting-started — Quick start guide

Mock Mode

For testing and development, enable mock mode:

REVERSECENTAUR_MOCK_MODE=true npx @reversecentaur/mcp

Or in your MCP client config:

{
  "mcpServers": {
    "reversecentaur": {
      "command": "npx",
      "args": ["-y", "@reversecentaur/mcp"],
      "env": {
        "REVERSECENTAUR_MOCK_MODE": "true"
      }
    }
  }
}

Mock mode returns realistic fake data without making any API calls. Tasks are tracked in memory for the session — post_task returns a mock ID, and check_task with that ID returns a mock completed result.

Programmatic Usage

import { createServer } from '@reversecentaur/mcp';

const server = createServer({
  apiKey: 'your-key',
  baseUrl: 'https://api.reversecentaur.ai',
  mockMode: false,
});

Example Conversation

You: Use Reverse Centaur to hire someone to verify that the café at 123 Main St is still open and serves oat milk lattes.

Claude: I'll post a verification task for that. (uses post_task with category "verification", budget $3.00)

Claude: Task posted! ID: task_abc123. Estimated match time: 10 minutes. I'll check back. (later, uses check_task)

Claude: The human worker confirmed: the café is open (closes at 9 PM) and yes, they serve oat milk lattes ($5.50). Fair Trade certified ✅

Fair Trade Standards

All tasks must meet category-specific pay minimums. The platform enforces a minimum effective hourly rate of $30/hr. Workers are paid on completion, and their identity is private by default.

Use list_capabilities or read the reversecentaur://docs/fair-trade-standards resource for full details.

Links

• Website: reversecentaur.ai
• API Docs: reversecentaur.ai/docs
• GitHub: github.com/ReverseCentaurAI/mcp-server

License

MIT