NETROOM
Programmatic access to everything on GitHub: repositories, commits, branches, issues, pull requests, releases, Actions, user and organisation profiles. Both REST and GraphQL are available, and GraphQL pulls nested data in a single round trip. Unauthenticated calls get 60 requests an hour per IP; a personal token or OAuth app raises that to 5,000, and GitHub Apps have their own budget. Tokens take a minute to create and are scoped by permission.
A hub of NASA's open APIs behind one key: the Astronomy Picture of the Day, Mars rover photos, the near-Earth asteroid catalogue, EPIC images of Earth, DONKI space weather, EONET natural-event tracking and the image and video library. DEMO_KEY works with no signup but is tightly capped at a few dozen calls an hour; a free named key emailed on signup raises it to a thousand an hour. JSON throughout, and generous enough for real apps.
Weather by coordinates, city name or postal code: current conditions, hourly and multi-day forecasts, historical data, air quality, geocoding and raster map tiles for precipitation and temperature. JSON responses with client libraries for nearly every language. The free key activates within about half an hour of signup and covers the basic endpoints under a daily cap; deep history and minute-by-minute forecasts sit behind paid plans. The default choice for a weather widget or a course project.
An HTTP wrapper over Telegram for bots: send and receive messages, inline keyboards and buttons, files and media, polls, payments, webhooks, group and channel handling, mini apps. Everything reduces to plain GET and POST calls to api.telegram.org with the token in the path - no OAuth dance and no SDK needed to start. BotFather issues a token in under a minute, free, with no cap on how many bots you run. Send-rate limits exist but are generous and documented. One of the quickest paths from idea to a working product.
Prices, market cap, volume and chart history across thousands of coins and hundreds of exchanges, plus developer activity and social stats. Endpoints cover coins, exchanges, trading pairs, NFTs and historical charts. Public access still exists but is rate-limited and now expects a demo key from your account; steady load without throttling needs the Pro plan. JSON responses, with wrappers for nearly every language.
Live foreign-exchange quotes: bid and ask prices for forex pairs and crypto, the list of tradable symbols, and a market-status check. REST endpoints plus a websocket stream, which matters if you need a ticker that ticks rather than a snapshot once a minute. A key is required and issued on signup. The free plan is tightly capped on request volume, so anything resembling a real trading panel lands on a paid tier.
Data from the December open-source drive: participants, the pull requests they sent, and the organisations and projects looking for contributions. Plain JSON, no key and no signup, paginated at 99 items with a page parameter and JSONP available through callback. Good raw material for a contribution dashboard or a learning project fed by real records. Activity is tied to December, so expect little movement out of season.
Numerical weather forecasts by coordinates, including an astronomy-focused one: cloud cover, atmospheric transparency, seeing, humidity, wind and temperature - the set you actually need to plan a night at the telescope. Derived from NOAA and NCEP models. No key, no signup: a plain GET with latitude, longitude and a product type (ASTRO, CIVIL, METEO). Responses come as JSON or as a ready-made forecast image.
Live and historical aircraft positions from ADS-B signals: coordinates, altitude, heading, speed, registration and callsign, plus track history. What sets it apart from other aggregators is that aircraft are not scrubbed on owner request, so coverage is fuller. Access runs through RapidAPI and a key is mandatory; the free allowance is thin and plans are priced per request. Pricey for a hobby flight tracker, solid as a source for a real product.
AI and machine-learning job listings scraped from nearly three hundred company sites: title, company, full description, slug and id all arrive in the list response, so there is no second round trip for details. Public read endpoints are open and free; a key is optional and buys a stable agent identity plus a per-key hourly throttle instead of the shared one. Paginated, with a separate catalog endpoint describing what is available.
Three dozen computer-vision jobs behind a single key: OCR, face detection and comparison, face search across a repository, object and logo detection, background removal, NSFW moderation, face swap, photo restoration and colourisation, style transfer. Images go in as a file upload or a URL. Billing is credit-based - light endpoints cost one credit, heavier ones two - so you budget by workload rather than by subscription count. Distributed via RapidAPI with a free tier.
Automated audio mastering: upload a track and the service levels the loudness, cleans up the frequency balance and hands back a finished file. You can set a target loudness, supply a reference track and pick the output format. The flow is asynchronous - create a job, poll its status, download the result. A key comes with signup; the free allowance is enough to evaluate it, beyond that it is paid. Sensible when your app needs a decent master and you have no engineer.
The LLM catalogue as a plain JSON feed: token prices, context-window sizes, lifecycle status and the retirement dates providers have declared, each with its stated replacement. Everything is read from official provider docs and refreshed daily, and every record carries a source URL. Three endpoints: the full catalogue, deprecations only, and an OpenAPI spec. No key, no signup, no rate limit and open CORS, so you can call it from a browser or from CI to catch a model sunset early.
Quotes from Attack on Titan: the line, the character who said it and sometimes the episode. No key, no signup, and only a couple of endpoints - a random quote and a filter by character - returning small JSON payloads. It is a one-developer project on Vercel, so do not count on indefinite uptime and cache what you pull. Perfectly serviceable as the data behind a first learning app, a Telegram bot or a quote-of-the-day widget.
A grab-bag of the utilities you end up rewriting in every project: QR generation, page screenshots, PDF rendering, image resize and format conversion, hashing, UUIDs and nanoids, base64, JWT decoding, Open Graph extraction from a URL, colour conversion. All of it behind one key and a Bearer header, callable from any language. The free tier is 100 calls a month, with paid plans from 9 dollars. The quota is small, so read it as a way to keep five dependencies out of a prototype.
Third-party API health in one place: for close to three hundred services - OpenAI and Anthropic through AWS, GitHub, Stripe and Slack - it returns a status of up, degraded or unknown, a category and the last-checked timestamp. No key needed, the response is a plain JSON list, and each entry links to a detail page and a README badge. Handy for showing on your own dashboard that the outage is not yours, or gating a deploy on dependency health.
A hub bundling several infrastructure APIs behind one key: DNS records and WHOIS by domain, IP geolocation, page screenshots, weather, currency rates and commodity prices. Requests go over GET or POST, the key travels either in an X-apiKey header or an apiKey query parameter, and responses come as JSON or XML depending on a format parameter or the Accept header. Keys are issued in the dashboard after signup and can be reset there if one leaks.
A directory of machine-readable API descriptions: thousands of OpenAPI and Swagger specs for public services, normalised to one format and version. You can pull the list of providers, every version of a given API, or a single spec file. No key, no signup, free and served from a CDN. The obvious uses are generating clients and types, seeding your own integrations catalogue, or feeding tooling that already speaks OpenAPI.
Real-time air quality readings - PM2.5, PM10, NO2, CO, SO2 and ozone - from over 11,000 monitoring stations and 1,000 cities, plus a 3-8 day forecast and basic weather. Calls look like api.waqi.info/feed/[city]/?token=..., responses are JSON, and there are map tile and widget endpoints for embedding. The token is free after registration and the quota is generous at 1,000 requests per second. Licensing is strict: no reselling, no paid apps, attribution required.
A counter that lives on someone else's server: pick a namespace and a key, hit the endpoint, the number goes up. A direct replacement for the retired countapi.xyz, handy for page hits, button clicks, downloads - anything you want to increment without standing up a database. No signup, no key, a tiny JSON response you can call straight from the browser. Free, with no durability guarantee: fine for a side project, not for billing.
A family of small utility APIs behind one account: email and phone validation, IP geolocation, exchange rates, timezone lookup, screenshots, image processing. Each product sits on its own subdomain with its own key, taken from the dashboard after signup. Every one has a free tier of a few hundred to a few thousand calls plus a per-second ceiling, with paid plans above that. Convenient when you would rather not assemble a zoo of vendors.
National, regional and religious holidays: pass a country plus year, month and day and get back names, local spellings and holiday types. Coverage spans 190-plus countries and some 3,500 regions, going a century backwards and forwards. A key comes with signup; the free plan is 1,000 requests at one request per second, and the next tier costs 99 dollars. Built for calendars, working-day maths and delivery scheduling.
Community-sourced reputation for IP addresses: how often an address has shown up in attacks, its country and network, and the abuse categories reported against it. The check, reports, blacklist and check-block endpoints read the database, while report pushes your own findings back into it. Keys are free after signup, with a daily quota set by your plan. The classic use is Fail2Ban, which ships an AbuseIPDB config out of the box.
One-line pieces of advice: the advice endpoint returns a random slip with its id, advice by id returns a specific one, and there is a keyword search. No key, no signup, no headers - just a GET and a small JSON body, with JSONP available via a callback parameter. Responses are cached for two seconds, so a repeat call inside that window returns the same slip. A perfect first fetch exercise or advice-of-the-day widget; there is no SLA.
Job ads aggregated from the major boards plus labour-market analytics: search by keyword, location, salary band and category, salary histograms, historical trends and top hiring companies. Every request targets one country, since the indexes are regional. You need an app_id and app_key, both issued right after developer signup. Interactive docs let you fire the endpoints from the browser before writing any code.
A reference set of Indian airports and airlines: IATA code, full name, city, state, pincode and airport type - domestic or international. Three endpoints cover the full list, lookup by code and lookup by name, returning JSON with total, status and message fields. No key, no signup, hosted on Vercel. The data is static, which makes this a ready-made lookup table for an airport picker rather than a source of schedules or fares.
Ready-made stock research as structured JSON: an investment thesis, a valuation view, insider-signal readings and an earnings summary, all generated by a model on top of live fundamentals. The shape is meant to be handed straight to an agent or rendered as a card, so you are not parsing filings yourself. A key is required after signup. This is analysis, not market data - go to a quotes API for price charts and come here for conclusions.
A catalogue of developer free tiers, startup credits and tool pricing: what each service gives away, what the next step up costs, and when the price last moved. Search and comparison endpoints are documented in a Swagger UI with full parameter and response schemas. No key or signup required. Useful when you are picking a stack and doing the budget maths, or building your own comparison front end on top of the data.
Job listings for engineers building agentic systems - LangChain, LangGraph, LlamaIndex, CrewAI, AutoGen. You get a filterable, sortable job list, a single job by slug, and a salary overview broken down by country and stack. No API key, a limit of 30 requests per 60 seconds per IP, and an OpenAPI 3.1 spec published alongside. There is also an MCP server exposing the same data if you would rather query it from your editor. Refreshed daily.
Editors' picks