agentbuilt

agentbuilt MCP server

A small, stateless Model Context Protocol server that gives any AI agent a free AI-readiness audit of a URL, plus an A2A endpoint exposing the same capability as an agent. It runs as plain Vercel serverless functions — no framework, no database, no SDK.

Live endpoint: https://agentbuilt.dev/api/mcp (Streamable HTTP, protocol 2025-06-18). Listed in the official MCP registry as dev.agentbuilt/agentbuilt.

Tools

Use it from a client

Claude.ai / Claude Desktop — Settings → Connectors → Add custom connector → URL https://agentbuilt.dev/api/mcp.

Cursor — .cursor/mcp.json:

{ "mcpServers": { "agentbuilt": { "url": "https://agentbuilt.dev/api/mcp" } } }

VS Code — .vscode/mcp.json:

{ "servers": { "agentbuilt": { "type": "http", "url": "https://agentbuilt.dev/api/mcp" } } }

curl

curl -s https://agentbuilt.dev/api/mcp -H 'content-type: application/json' -H 'accept: application/json' \

-d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"audit_ai_readiness","arguments":{"url":"https://example.com"}}}'

A2A — agent card at https://agentbuilt.dev/.well-known/agent-card.json; message/send to https://agentbuilt.dev/api/a2a with a message containing a URL.

Why the readiness check is built the way it is

• SSRF-safe fetching (api/_lib/net.js): the hostname is resolved once, every address is validated against private / link-local / CGNAT / metadata ranges (IPv4 and IPv6, including v4-mapped, NAT64 and 6to4 forms), and the HTTPS connection is pinned to the validated address via Node's lookup option — so a hostile nameserver can't answer public for the check and private for the connect. Redirects are followed manually and re-validated per hop. Only ports 80 and 443.
• Honest crawler-access reporting: if a site refuses the anonymous request, the check retries as the documented AI crawler user-agents. A 403 to *our* spoofed GPTBot is reported as exactly that — bot managers such as Cloudflare verify real crawlers by IP and reject impostors — never as "GPTBot is blocked". We learned this the hard way on a real audit; the only proof of a block is a robots rule or the assistant itself failing to read the page.
• Real-JSON / real-XML probes: a SPA that returns 200 HTML for /llms.txt or /sitemap.xml is not counted as having them.
• Stateless: no sessions, no storage for the free tool. GET with Accept: text/event-stream returns 405 by design (no server-initiated streams).

Deploy your own

Fork, vercel deploy. The free tools need no environment variables. request_visibility_audit needs WAITLIST_KEY (32-byte base64, for sealing emails), APIFY_TOKEN and WAITLIST_DATASET_ID; without them it returns a clear error and the other tools keep working.

server.json is the registry manifest; PUBLISHING.md records the exact mcp-publisher commands and the gotchas we hit (schema version, description length, UTF-8 BOM).

About

agentbuilt is an AI-operated studio: an AI agent builds and runs it, and Matt Edward (Calgary, Canada) is the accountable human owner. The studio publishes its ledger and its data — e.g. AI share of voice: lease accounting software — at agentbuilt.dev.

MIT licensed. Issues and PRs welcome; an AI agent reads them, and the owner is accountable for what gets merged.