HTTPayer MCP server

@httpayer/mcp

MCP (Model Context Protocol) server for HTTPayer. Lets AI agents call x402-enabled APIs using credit balance — no wallets, no blockchain, no Web3 knowledge required.

• Dashboard & API keys: app.httpayer.com
• npm: @httpayer/mcp
• GitHub: httpayer/mcp

Quickstart

With an AI agent (recommended)

Paste this into any MCP-compatible agent (Claude Code, Cursor, Windsurf, OpenCode...):

Set up https://httpayer.com/skill.md

The agent detects your environment and handles everything automatically.

Without an agent (manual)

1. Run setup:

npx @httpayer/mcp setup

Get your API key at app.httpayer.com when prompted.

Flags:

2. Add to your client:

Claude Code:

claude mcp add httpayer --scope user -- npx -y @httpayer/mcp@latest

Claude Desktop (~/Library/Application Support/Claude/claudedesktopconfig.json on macOS, %APPDATA%\Claude\claudedesktopconfig.json on Windows):

{
  "mcpServers": {
    "httpayer": {
      "command": "npx",
      "args": ["-y", "@httpayer/mcp@latest"]
    }
  }
}

Cursor (.cursor/mcp.json), Windsurf (.windsurf/mcp.json), Cline (.cline/mcp_settings.json):

{
  "mcpServers": {
    "httpayer": {
      "command": "npx",
      "args": ["-y", "@httpayer/mcp@latest"]
    }
  }
}

OpenCode (opencode.json or ~/.config/opencode/config.json):

{
  "mcp": {
    "httpayer": {
      "type": "local",
      "command": ["npx", "-y", "@httpayer/mcp@latest"],
      "enabled": true
    }
  }
}

Zed:

{
  "context_servers": {
    "httpayer": {
      "command": {
        "path": "npx",
        "args": ["-y", "@httpayer/mcp@latest"]
      }
    }
  }
}

3. Restart your client and verify:

Ask your agent: "fetch https://api.httpayer.com/demo/v1/base-weather"

A weather response means HTTPayer is working.

How it works

User prompt
    │
    ▼
AI agent (Claude Code, Cursor, Windsurf...)
    │  uses MCP tools + prompts + resources
    ▼
@httpayer/mcp (local MCP server via npx)
    │  REST calls with x-api-key header
    ▼
api.httpayer.com
    │  proxy handles x402 payment to target
    ▼
Target x402-gated API

Runtime flow

1. Your client launches the MCP server via npx -y @httpayer/mcp@latest on startup (stdio transport).
2. The server reads the API key from ~/.httpayer/mcp-config.json.
3. The agent receives the tool list, system instructions, prompts, and resources in its context.
4. When the agent calls fetch, the MCP server forwards the request to POST https://api.httpayer.com/proxy.
5. HTTPayer's proxy detects a 402, pays using your credits, retries, and returns the final response.
6. The result (status, body, headers) comes back to the agent.

MCP capabilities

This server exposes three MCP primitives so agents get context automatically — without the user having to ask.

Tools

Six tools (see full reference below).

Prompts

Compatible clients (Claude Desktop, Cursor, and others) call prompts/list on connection and inject these into the agent's context proactively.

Resources

Shortened. The full README is on GitHub.