Hi HN, I’m a reverse engineer, and I’ve seen the same problem repeatedly: people need data, but the path from “I need this” to “my app, agent, or workflow can use it” is messy.

Vibe coders want a working endpoint in minutes. Developers want clean docs, predictable JSON, and no surprise integration work. Businesses want to enrich lists, monitor changes, and safely expose internal data. AI agents need APIs they can discover and call reliably. Sometimes, the API simply doesn't exist.

ApiClay makes that whole loop easier.

You can search a catalogue of APIs and datasets, inspect them in a playground, and copy ready-to-run JavaScript, Python, or cURL snippets into your app. Each API has its own reference, pricing, trials, and usage terms, so you can see what you’re calling before you go live.

But ApiClay is not just an API marketplace.

If the API you need does not exist, you can create one with Website to API: give it a page, map the fields you care about, and publish a stable JSON endpoint. It works with static and JavaScript-heavy pages, and can return clean Markdown, JSON, text, or links.

You can also turn what you already have into an API:

* MySQL, PostgreSQL, MongoDB, Google Sheets, Airtable, Excel/CSV, and HTTP services can become API endpoints.

* Import an OpenAPI/Swagger file to get docs, a playground, and billing for an existing API.

* Publish only the fields you choose, control access, set trials, plans, usage limits, and pricing.

* Aggregate multiple providers into one tidy response for comparison-style products.

For AI, ApiClay exposes an MCP endpoint so Claude, ChatGPT, or custom agents can search for an API, inspect it, and call it. The idea is simple: instead of an agent hallucinating a data source, it finds a real API and returns an answer backed by live data.

There are also practical data tools beyond discovery:

* Websets / enrichment: upload a list, enrich each row, set a spend cap, and export the result.

* Monitors: watch an API or webpage and receive a signed webhook when something changes.

* Cloud browser: automate a browser session for pages behind clicks or JavaScript rendering, then return the values your app needs.

* Extraction: turn a page into clean Markdown, JSON, text, or links without maintaining your own scraper.

For people publishing APIs, credentials stay encrypted on ApiClay and are not exposed to buyers; publishers control pricing, limits, trials, and access. For consumers, browsing and reading docs are free, while paid calls are charged per request and shown before use.

*ApiClay is where you find the data API you need, build the one that is missing, let AI agents use it, and optionally sell it.*

We’d love feedback from HN—especially from developers building data-heavy products, teams dealing with messy internal sources, and anyone experimenting with agent-driven workflows.

Exact: A new agent-native app framework written in Rust, from Expo team