Bismuth — x402 MCP Server

Pay-per-use APIs for AI agents, powered by the Bismuth (x402 API Network). One npm install, automatic USDC micropayments on Base.

Tools

| Tool | Description | Price | |------|-------------|-------| | x402_network_info | List all APIs with pricing and health status | Free | | x402_screenshot | Capture any URL as a base64 image | $0.01 / capture | | x402_pdf_extract | Extract text from a PDF via URL | $0.01 / extraction | | x402_sentiment | Real-time sentiment analysis for a crypto coin | $0.01 / query | | x402_market_overview | Broad crypto market sentiment overview | $0.05 / query | | x402_intelligence | Multi-source crypto intelligence (CoinGecko, DeFiLlama, news, GitHub) | $0.10 / query | | x402_send_email | Send transactional emails via Resend with CC, BCC, and file attachments | $0.01 / email | | x402_scrape_url | Scrape any URL and return structured markdown, links, tables, metadata | $0.02 / scrape | | x402_convert_file | Convert files: image resize/reformat, CSV to JSON, HTML to PDF, DOCX to PDF | $0.02 / conversion | | x402_web_search | Search the web via Tavily with ranked results and optional AI answer | $0.01 / search | | x402_transcribe_audio | Transcribe audio files with auto language detection and word timestamps | $0.05 / transcription | | x402_crawl_site | Crawl a website via BFS and return per-page markdown, links, tables, images, metadata | $0.10 / crawl |

What's New in 2.0.0

Three capability extensions and one new tool:

• Shallow Site Crawl — new x402_crawl_site tool: BFS crawl up to 15 pages from a seed URL
• Email CC/BCC/Attachments — x402_send_email now accepts cc, bcc, and base64 file attachments
• DOCX to PDF — x402_convert_file now supports type: "docx" for DOCX document conversion

Quick Start — Free Mode

No wallet or private key needed. Add the server to your MCP client config:

{
  "mcpServers": {
    "x402": {
      "command": "npx",
      "args": ["-y", "x402-mcp-server"]
    }
  }
}

Free mode limitations:

• Screenshots limited to example.com, example.org, and httpbin.org
• PDF extraction limited to first 3 pages
• Sentiment returns mock data with real market structure
• Email returns a fake message ID (no delivery)
• Scraping returns fixture data (no live scraping)
• File conversion returns fixture data (no live conversion)
• Web search returns fixture results (no live search)
• Transcription returns fixture transcript (no live transcription)
• Site crawling returns fixture data (no live crawl)

Quick Start — Paid Mode

Requires a Base wallet funded with USDC.

{
  "mcpServers": {
    "x402": {
      "command": "npx",
      "args": ["-y", "x402-mcp-server"],
      "env": {
        "X402_PRIVATE_KEY": "your-private-key-here"
      }
    }
  }
}

Never commit your private key. Store it in your system environment or a local .env file loaded by your shell.

You need USDC on the Base network. Base is an Ethereum L2 with low transaction fees. See the full wallet setup guide for detailed instructions.

MCP Client Configs

Omit the env block entirely for free mode.

Claude Desktop

Config file location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "x402": {
      "command": "npx",
      "args": ["-y", "x402-mcp-server"],
      "env": {
        "X402_PRIVATE_KEY": "your-private-key-here"
      }
    }
  }
}

Claude Code

claude mcp add --transport stdio x402 -- npx -y x402-mcp-server

Then set X402_PRIVATE_KEY in your environment.

Cursor

Config file: ~/.cursor/mcp.json

{
  "mcpServers": {
    "x402": {
      "command": "npx",
      "args": ["-y", "x402-mcp-server"],
      "env": {
        "X402_PRIVATE_KEY": "your-private-key-here"
      }
    }
  }
}

Windsurf

Config file: ~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "x402": {
      "command": "npx",
      "args": ["-y", "x402-mcp-server"],
      "env": {
        "X402_PRIVATE_KEY": "your-private-key-here"
      }
    }
  }
}

How It Works

1. Your AI agent calls a tool (e.g., x402_screenshot)
2. The MCP server makes an HTTP request to the API
3. The API responds with 402 Payment Required
4. x402-fetch automatically signs a USDC payment on Base and retries
5. The API returns the result

The payment flow is handled by x402-fetch — your agent never needs to manage transactions directly.

License

MIT