{"slug": "what-a-seller-side-http-402-mcp-paywall-looks-like", "title": "What a seller-side HTTP 402 + MCP paywall looks like", "summary": "A developer has released x402-micro-tollgate, an open-source Express process that acts as both an HTTP 402 reverse proxy and an MCP server, enabling agents to pay per API call without API keys. The tool returns a 402 Payment Required status for unpaid requests and proxies them after settlement, with MCP tools for server info, quotes, and proxied requests.", "body_md": "I needed agents to pay per call against an existing HTTP API without handing out API keys. x402-micro-tollgate is a thin Express process that is both an HTTP 402 reverse proxy and an MCP server.\n\nUnpaid gated routes (default `/v1`\n\n) return protocol 402. After settlement, the request is proxied to UPSTREAM_URL. `/health`\n\nstays free. Same process exposes MCP tools: `server_info`\n\n(free), `get_quote`\n\n/ `proxy_request`\n\n(paid).\n\nDemo (no CDP keys):\n\n```\ncurl -i https://x402-micro-tollgate.onrender.com/v1/quote\n# HTTP/1.1 402 Payment Required\n```\n\nSelf-host:\n\n```\nnpx x402-micro-tollgate\n```\n\nRepo: [https://github.com/kevin2003050666-coder/x402-micro-tollgate](https://github.com/kevin2003050666-coder/x402-micro-tollgate)\n\nnpm: [https://www.npmjs.com/package/x402-micro-tollgate](https://www.npmjs.com/package/x402-micro-tollgate)\n\nMCP Registry: `io.github.kevin2003050666-coder/x402-micro-tollgate`", "url": "https://wpnews.pro/news/what-a-seller-side-http-402-mcp-paywall-looks-like", "canonical_source": "https://dev.to/kevin2003050666coder/what-a-seller-side-http-402-mcp-paywall-looks-like-36n", "published_at": "2026-09-01 10:29:38+00:00", "updated_at": "2026-09-01 10:53:07.182104+00:00", "lang": "en", "topics": ["developer-tools", "ai-agents", "ai-infrastructure"], "entities": ["x402-micro-tollgate", "MCP", "Express", "Render"], "alternates": {"html": "https://wpnews.pro/news/what-a-seller-side-http-402-mcp-paywall-looks-like", "markdown": "https://wpnews.pro/news/what-a-seller-side-http-402-mcp-paywall-looks-like.md", "text": "https://wpnews.pro/news/what-a-seller-side-http-402-mcp-paywall-looks-like.txt", "jsonld": "https://wpnews.pro/news/what-a-seller-side-http-402-mcp-paywall-looks-like.jsonld"}}