DopamineDesk x402 Marketplace MCP Server

Model Context Protocol (MCP) server and machine-to-machine data API gateway powered by the x402 Payment Protocol on Base Mainnet.

Install

Run directly with npm:

npx -y dopaminedesk-ai-data-marketplace-mcp

Claude Desktop or another stdio-compatible MCP client:

{
  "mcpServers": {
    "dopaminedesk-data-arcade": {
      "command": "npx",
      "args": ["-y", "dopaminedesk-ai-data-marketplace-mcp"]
    }
  }
}

Optional one-call purchasing

Version 2.3.1 can complete the x402 challenge, authorization, retry, and settlement automatically. The buyer key stays inside the buyer's local MCP process; the marketplace never receives it. Use a dedicated low-balance Base wallet, not a primary wallet.

{
  "mcpServers": {
    "dopaminedesk-data-arcade": {
      "command": "npx",
      "args": ["-y", "dopaminedesk-ai-data-marketplace-mcp"],
      "env": {
        "X402_AUTO_PAY": "true",
        "X402_EVM_PRIVATE_KEY": "YOUR_DEDICATED_BUYER_WALLET_KEY",
        "X402_MAX_PAYMENT_USDC": "0.25"
      }
    }
  }
}

Call any product with auto_pay: true. The adapter refuses a price above X402_MAX_PAYMENT_USDC, refuses conflicting payment inputs, and never falls back to an uncapped purchase. Without these environment variables, preview and manual-signature behavior remains unchanged.

Official MCP Registry name: io.github.jblaz6335/ai-data-marketplace.

Published Distribution

• npm: dopaminedesk-ai-data-marketplace-mcp, version 2.3.1
• Official MCP Registry: io.github.jblaz6335/ai-data-marketplace, active
• Smithery: jblaz6335/dopaminedesk-agent-data-arcade, live
• PulseMCP: queued for ingestion through its Official MCP Registry feed

The production catalog contains 44 capability-audited billable tools and 87 total public catalog entries. The billable set consists of 37 live-source tools, 1 verified government-contract snapshot, 5 input-sensitive processors, and 1 verified payment-credit service. Of all public entries, 47 are operational and 40 are labeled preview-only fixtures. Every API response identifies its data mode, availability, billing state, and backing source.

The MCP adapter builds its tool list from the production OpenAPI document. It does not maintain a stale hand-written endpoint list.

Production API Service

• Base Service URL: https://ai-data-marketplace-1042299154756.us-central1.run.app
• OpenAPI Specification: https://ai-data-marketplace-1042299154756.us-central1.run.app/openapi.json
• Postman 1-Click Collection: https://ai-data-marketplace-1042299154756.us-central1.run.app/postman.json
• LLM Manifest: https://ai-data-marketplace-1042299154756.us-central1.run.app/llms.txt
• x402 Protocol Manifest: https://ai-data-marketplace-1042299154756.us-central1.run.app/.well-known/x402
• x402scan Marketplace Page: https://www.x402scan.com/server/8dd63536-ba25-40f4-b36a-7d05ed18d007

The paid OpenAPI contract contains exactly the 44 billable products. The broader catalog endpoint retains 40 clearly labeled preview fixtures for evaluation, but those routes do not appear as purchasable OpenAPI products.

Data Schema Inspection Mode

Client applications and autonomous agents can evaluate response schemas and data quality without executing a paid transaction by adding the preview=true parameter:

curl -s "https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/candles?preview=true&ticker=bitcoin"

Endpoints & Pricing Catalog

See the production x402 manifest or OpenAPI document for the complete live list. Preview-only fixtures return TOOL_NOT_FOR_SALE without preview=true.

Standard x402 v2 Payment Flow

Every billable product uses x402 v2 exact payments through the PayAI facilitator on Base mainnet:

1. Call a paid endpoint without payment and read the base64-encoded PAYMENT-REQUIRED response header.
2. Use an x402 v2 client and buyer wallet to sign the exact USDC authorization.
3. Retry with the resulting PAYMENT-SIGNATURE header.
4. On success, read the settled transaction details from PAYMENT-RESPONSE.

The MCP adapter returns both the decoded challenge and the original payment_required_header. A compatible buyer can sign that challenge and retry the same tool with the payment_signature input. Buyers who configure the optional capped local wallet can instead set auto_pay: true and complete the entire flow in one tool call. Successful responses include payment_response_header.

The server advertises Bazaar discovery schemas for all 44 products. PayAI handles verification and settlement; USDC is delivered directly to the configured marketplace wallet.

Legacy Integration Client (client.py)

The included Python helper preserves the confirmed-transaction fallback for older integrations that do not yet use an x402 v2 signing client:

import requests

MARKETPLACE_URL = "https://ai-data-marketplace-1042299154756.us-central1.run.app"

# 1. Request the standard challenge and legacy invoice body
invoice_response = requests.get(f"{MARKETPLACE_URL}/api/v1/candles?ticker=bitcoin")
invoice = invoice_response.json()["x402_invoice"]
print("Pay this Base USDC invoice with an external wallet:", invoice)

# 2. After paying externally, retry with the real Base transaction hash and invoice ID
headers = {
    "x-402-payment-tx": "0x_YOUR_REAL_BASE_TRANSACTION_HASH",
    "x-402-payment-id": invoice["payment_id"]
}
data = requests.get(f"{MARKETPLACE_URL}/api/v1/candles?ticker=bitcoin", headers=headers).json()
print("Payload Result:", data)

License

MIT License. Open-source Model Context Protocol server.