MCP

MCP (Model Context Protocol) is an open protocol that lets an AI application (Claude Code, Codex, Cursor or a custom agent) discover tools on a server and call them with structured arguments. The server describes each tool with a name, a description and a JSON input schema; the client shows them to the model, and the model decides when to call one.

What are the pieces?

• MCP server: exposes tools. FastAF’s is at https://api.fastaf.co/mcp.
• Transport: how messages travel. FastAF uses Streamable HTTP, so it runs remotely with nothing to install.
• tools/list: the call a client makes to learn which tools exist. On FastAF it is public.
• tools/call: runs a tool. On FastAF it needs an API key or an OAuth token.

Which tools does FastAF expose?

FastAF’s 23 tools: google_search, google_maps_places, google_shopping_prices, google_ai_answer, google_images, search_news, search_scholar, search_jobs, search_patents, search_flights, bing_search, amazon_product, search_ebay, search_walmart, search_zillow, search_youtube, youtube_transcript, read_reddit, get_linkedin_profile, search_linkedin_jobs, x_profile, scrape_url and extract.

Example: connecting and calling

claude mcp add --transport http fastaf https://api.fastaf.co/mcp \
  --header "Authorization: Bearer $FASTAF_API_KEY"

The agent can then call amazon_product with {"asin": "B0CHX1W1XY", "marketplace": "com"} or x_profile with {"username": "nasa"}. Every successful result reports credits_used and credits_remaining. Step by step: add FastAF to Claude Code, Codex and Cursor.

How are MCP calls paid?

From your account balance: 500 free credits every month after email verification (spent first), then optional prepaid packs. MCP is not paid with x402; the x402 path is REST only.

What about tool bloat?

Every tool schema a client loads takes up model context. The MCP server always lists all its tools; choosing a subset happens in the client. See Too many MCP tools?.

Where is FastAF listed?

MCP servers are listed in registries so clients can find them. FastAF is in the official MCP Registry as co.fastaf/fastaf and publishes a server card at https://api.fastaf.co/.well-known/mcp/server-card.json.

MCP or REST?

The same data is available over REST at /v1/<name>. Use MCP when a model chooses the tool; use REST when your own code decides what to call.

Related: x402 · Pay-per-call API

Related terms

• x402: x402 is a protocol for paying for HTTP resources using a payment challenge and a signed retry.
• HTTP 402: HTTP 402 Payment Required is an HTTP status code indicating that payment is required for a resource.
• Pay-per-call API: A pay-per-call API charges for individual API requests rather than requiring a recurring subscription.

What it costs: FastAF pricing and credit packs · x402 price list per call

Frequently asked questions