goodnight000/api-anything: Turn any website into an API your agent can call. Learns from the site's own frontend, heals itself when the site changes.

Turn any website into an API your agent can call. Learns from the site's own frontend, heals itself when the site changes. - goodnight000/api-anything

Summary

API Anything is a TypeScript tool that turns a website into a callable API for AI agents. It learns operations by recording a headless browser's network traffic across two example inputs, then lets agents invoke those operations via MCP, CLI, or TypeScript over plain HTTP. The repository ships 22 pre-built read operations across 9 sites and can re-learn an operation when it breaks.

What it is useful for

API Anything is useful when you want an LLM agent to retrieve structured data from a site without paying the time and token cost of driving a full browser on every request. The tool captures the underlying HTTP request once, then replays it as a fast JSON call.

Concrete scenarios documented in the README:

• Replacing Playwright-style browsing for routine reads such as Hacker News link lists, YouTube search, Google Flights search, or Amazon/Airbnb search.
• Reading Goodreads, which lost its public API in 2020. The README describes an "explorer" run that produced search, book details, author lists, and reviews, with all 146 follow-up calls going over plain HTTP.
• Sites behind a login: api-anything login <site> imports cookies from a Chrome, Arc, Brave, Edge, Chromium, Vivaldi, or Firefox profile you are already signed into, so the agent reuses your session without typing a password. Saved operations hold references to cookies and tokens, not their values, so a refreshed session keeps working.

Documented limits to be aware of:

• It only knows operations it was taught; it does not cover every feature of every site.
• Repair can fail. There is no CAPTCHA solving, and if a site challenges Chrome you must clear it by hand.
• Bundled ops are read-only. Writes are tested only against a local fixture and require --allow-writes; an HTTP 2xx does not prove a message was delivered.
• It is a local tool running on your machine with your sessions; credentials live in ~/.api-anything. The README states you are responsible for how you use it under each site's terms.

How engineers can use it

The README documents two install paths.

Agent-driven install:

1. Ask Claude Code or Codex: "Set up API Anything for me: https://github.com/goodnight000/api-anything/blob/main/INSTALL.md".
2. The agent checks Node 22.13+, builds and installs the api-anything command, verifies a call works, then wires up the skill and MCP server.
3. Restart the agent and ask a real question, e.g., "What does Goodreads rate Piranesi?".

Manual install (the package is not on npm yet, and the README warns against npm install -g github:...):

git clone https://github.com/goodnight000/api-anything.git && cd api-anything
npm ci && npm install -g "$(npm pack --silent)"
api-anything call hacker-news search query=sqlite

A working call returns {"ok":true,"class":"ok","tier":1,...}. tier: 1 means plain HTTP with no browser. A failure returns ok: false with a class, reason, and next step.

To expose operations to an agent, add the MCP server:

codex mcp add api-anything -- api-anything mcp
claude mcp add --scope user api-anything -- api-anything mcp

Over MCP the agent gets four tools: list_sites, list_operations, call_operation, and login.

To teach it a new site, define an operation with a placeholder URL and two inputs:

api-anything add hn-demo links \
  --trigger 'https://news.ycombinator.com/from?site={domain}' \
  --example domain=github.com --example2 domain=github.io --match path=/from \
  --html '{"items":"tr.athing","fields":{"title":".titleline > a","url":".titleline > a@href"}}'

api-anything call hn-demo links domain=arxiv.org

The browser loads the page once per example; the part of the request that changes with the input becomes a parameter, and the rest is stored as a template. If a call later fails (for example, a rotated id or moved field), API Anything re-learns it and only saves the new version after a replay succeeds, otherwise it returns an error rather than someone else's data.

api-anything ops <site> lists the parameters and caveats for each built-in site. Further reference material lives in docs/REFERENCE.md and the design notes in docs/DESIGN.md.