DopamineDesk x402 Marketplace MCP Server

Decision-ready machine-to-machine reports paid per request with the x402 Payment Protocol on Base Mainnet.

No API key. No account. No subscription. Buy one current answer in USDC when a workflow needs it. The catalog includes agent-readiness audits, vendor onboarding risk, transaction preflight, live x402 opportunity research, company intelligence, endpoint verification, website due diligence, VIN safety, market checks, security research, and atomic EVM reads.

Every billable route accepts ?preview=true. The preview is a live contract proof showing the source, freshness, required inputs, and response shape. It deliberately withholds the decision-ready values delivered by the paid call.

Start with the free find_marketplace_products MCP tool. Give it the buyer's task in plain language and it returns three ranked live products plus one recommended_purchase containing the exact price, required inputs, and ready preview and paid-call payloads. Replace the example inputs with the buyer's real values, preview when available, and only use the paid call after the user authorizes the listed price and payment method.

Buyer-ready outcomes

These are complete paid deliverables, not teaser text. The lower-level catalog remains available for workflows that need a single chain read, filing, sanctions check, quote, or verification result.

If this open-source buyer adapter saves you integration work, you can support its maintenance on Ko-fi.

Install

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

Use it from any stdio-compatible MCP client:

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

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

Small tool list for existing agents

Set X402_TOOL_MODE=compact to expose just find_marketplace_products and purchase_marketplace_product. All live products remain available through those two tools. The default full mode keeps the product-specific tools for existing integrations.

No environment variable or wallet key is required to start the default server. A wallet is needed only if the buyer chooses locally signed auto-pay. The remote /mcp URL is a separate authenticated publisher integration, not the public stdio install URL.

Ready-to-copy configurations and a free end-to-end client check are in examples/README.md. The check discovers a real product and requests its free preview. It never signs or submits a payment.

Buy with credits instead of configuring a wallet

The service is already indexed in APIHub's external x402 catalog. Buyers with APIHub credits can ask its proxy to sign and settle a marketplace call without keeping a Base wallet or gas in the calling process:

npx @apihubio/cli register
npx @apihubio/cli topup 5
npx @apihubio/cli call https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/evm_block_number

APIHub is an independent third party with its own account, credit, markup, and terms. Direct x402 remains the self-custody path. Both routes settle the protected endpoint before its paid result is delivered.

Inspect a live contract

curl "https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/company_intelligence?preview=true&domain=example.com"

The proof includes source, freshness, request parameters, top-level fields, response shape, and a purchase block. Decision-ready values remain in the paid result.

Optional one-call purchasing

The current npm release can complete the x402 challenge, authorization, retry, and settlement automatically. Install the public package directly:

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

The buyer key stays inside the local MCP process and is never sent to the marketplace. Use a dedicated low-balance Base wallet, not a primary wallet.

{
  "mcpServers": {
    "dopaminedesk-data-marketplace": {
      "command": "npx",
      "args": ["-y", "dopaminedesk-ai-data-marketplace-mcp@2.11.3"],
      "env": {
        "X402_AUTO_PAY": "true",
        "X402_EVM_PRIVATE_KEY": "YOUR_DEDICATED_BUYER_WALLET_KEY",
        "X402_MAX_PAYMENT_USDC": "0.25"
      }
    }
  }
}

Call a product with auto_pay: true. The adapter refuses disabled, conflicting, invalid, or over-cap purchases. It never falls back to an uncapped payment.

For automated client installation, see llms-install.md. Its default configuration exposes free discovery and previews without collecting a wallet key or enabling automatic payment.

Verification and engineering scope

The public verification hub and machine verification record expose the production evidence.

I built this adapter around these constraints:

• the production OpenAPI contract is the source of truth for tool discovery;
• live contract proofs verify the source and schema without replacing the paid product;
• automatic purchasing is opt-in, locally signed, and protected by a hard per-call cap;
• conflicting, malformed, disabled, and over-cap payment attempts fail closed;
• settlement details stay attached to the delivered result for reconciliation.

Run the verification suite locally:

npm ci
npm test

Production contracts