x4PayAPI Market

PayAPI Market in Claude Desktop

Claude Desktop talks to PayAPI Market through one MCP server, the same server every other client uses. Add the block on this page to claude_desktop_config.json and restart Claude. The only keys in that block are mcpServers, payapi and url, and the url is https://payapi.market/mcp. After the restart the client has four tools. search_apis, list_apis and get_api are read-only catalogue calls. submit_listing is free, rate limited, and it goes to pending review. It does not verify a listing and it does not make one live. Paying is separate from those tools. When the agent calls a provider, it pays over x402 in USDC on Base, Solana or Algorand, with no API key. Settlement-verified means a paid route with an on-chain receipt. The examples below are claimed verified listings the tools can return. Unclaimed (bazaar) imports are labelled and are not the examples. Listing an API is free and the provider keeps 100% of each settled call.

1042 APIs and 6311 endpoints match this page. 1031 are settlement-verified: a paid route with an on-chain receipt.

MCP config

Add this to claude_desktop_config.json and restart Claude Desktop.

{
  "mcpServers": {
    "payapi": {
      "url": "https://payapi.market/mcp"
    }
  }
}

What the four tools do

How paying works

The MCP server does not charge and it does not return HTTP 402. The agent pays the provider over x402 in USDC on Base, Solana or Algorand. No API key. Settlement-verified means a paid route with an on-chain receipt.

Settlement-verified examples

Unclaimed (bazaar) imports

These rows were imported and the provider has not claimed them. They are not the examples above.

Related pages

Questions

What do I paste into Claude Desktop?

The mcpServers block on this page, into claude_desktop_config.json, then restart. The url is https://payapi.market/mcp. Do not add a second URL or an SSE path for the catalogue.

What do the four MCP tools do?

search_apis searches the catalogue, list_apis browses it, and get_api fetches one listing. Those three are read-only. submit_listing is free, rate limited, and it goes to pending review. It never sets payment_verified.

How does Claude pay for an API once it has found one?

Not through the MCP server. The agent calls the provider and pays over x402 in USDC on Base, Solana or Algorand. No API key. A settlement-verified listing has a paid route with an on-chain receipt.