9 Free Endpoints I Built Into a Financial Data API — With Curl/Python Examples

A developer built XFINLAB, a financial intelligence API offering market events, sentiment, technical analysis, and macro data, with an MCP server for AI agents. The writeup details nine endpoints, including free no-key website tools and versioned X-API-Key intelligence endpoints for technical analysis, Monte Carlo stress testing, and opportunity radar signals. The developer notes the free tools lack versioning guarantees or SLAs and recommends the official API for production integrations.

9 Free Endpoints I Built Into a Financial Data API — With Curl/Python Examples I've been building XFINLAB, a financial intelligence API — market events, sentiment, technical analysis, macro data — with an MCP server for AI agents on top. Along the way I also built a handful of free, no-key tools directly into the site. Sharing the actual working requests here, labeled honestly by which ones you should actually build on vs which are just free site plumbing: 🔑 Official Intelligence API — versioned, X-API-Key auth, documented, part of the paid product. Safe to build a production integration on. 🌐 Free website tool, no key — powers a public page on xfinlab.com directly. No auth, no versioning guarantee, no SLA. Fine for personal scripts, quick lookups, or prototyping — not recommended for anything you depend on staying stable, since it can change without notice the same way any other part of a website's frontend can. Free web tool: bash curl " https://api.xfinlab.com/api/chart-search/AAPL?period=6mo&interval=1d https://api.xfinlab.com/api/chart-search/AAPL?period=6mo&interval=1d " Official API X-API-Key, recommended for real use : bash curl " https://api.xfinlab.com/api/intelligence/v1/technical/AAPL https://api.xfinlab.com/api/intelligence/v1/technical/AAPL " \ -H "X-API-Key: YOUR KEY" python import requests r = requests.get " https://api.xfinlab.com/api/intelligence/v1/technical/AAPL https://api.xfinlab.com/api/intelligence/v1/technical/AAPL ", headers={"X-API-Key": "YOUR KEY"}, data = r.json "data" print data "confluence" "direction" , data "confluence" "confidence pct" print data "support" , data "resistance" Response includes confluence direction/confidence/bullish & bearish signal list , trend, support/resistance, decision levels, and market structure — all computed from real OHLC history, never AI-guessed. The official API version omits raw OHLC bars licensing ; the free web version includes them. bash curl -X POST " https://api.xfinlab.com/api/stress-lab https://api.xfinlab.com/api/stress-lab " \ -H "Content-Type: application/json" \ -d '{"symbol": "Stocks/Bonds 60/40", "amount": 100000, "horizon days": 252}' Official API: python import requests r = requests.post " https://api.xfinlab.com/api/intelligence/v1/stress-test https://api.xfinlab.com/api/intelligence/v1/stress-test ", headers={"X-API-Key": "YOUR KEY"}, json={"symbol": "AAPL", "amount": 100000, "horizon days": 252}, d = r.json "data" print f"Median outcome: ${d 'ending value p50' :,.0f}" print f"5th percentile bad case : ${d 'ending value p5' :,.0f}" print f"Median max drawdown: {d 'max drawdown p50 pct' }%" This runs a real bootstrap Monte Carlo over actual historical returns n real observations tells you exactly how much real history backed the simulation — not a fabricated volatility assumption. Returns today's top confluence-ranked signals across stocks/futures/crypto: {date, signals: {ticker, label, price, confluence direction, confluence confidence pct, ...} , locked count, plan}. locked count tells you how many additional rows exist behind a login — this endpoint intentionally rations rows for non-logged-in callers, so don't build anything that assumes a fixed row count. bash curl " https://api.xfinlab.com/api/free-tools-demo/opportunity-radar https://api.xfinlab.com/api/free-tools-demo/opportunity-radar " bash curl " https://api.xfinlab.com/api/intelligence/v1/opportunity-radar https://api.xfinlab.com/api/intelligence/v1/opportunity-radar " \ -H "X-API-Key: YOUR KEY" Both return the same shape: real % change per indicator across real estate, supply chain, consumer demand, energy, agriculture — each indicator reports its own trailing change against itself, never a fabricated cross-industry composite score see methodology note in the response for the exact math . Returns AI-written commentary conclusion, analysis grounded in the filter criteria you pass — this is a free-text research aid, not a structured list-of-tickers-with-scores endpoint. If you need a structured, code-friendly screen, this isn't it yet flagging as a real gap, not glossing over it . Returns z score, correlation, divergence, and which side of the pair is richer symbol/cheaper symbol — a correlation + z-score divergence read on the real historical spread, explicitly not a formal cointegration test the page says so, and so does the API . Combines real market data, technicals, and news sentiment into bullish probability/bearish probability. The page itself carries a disclaimer that the underlying scoring formulas aren't yet backtested — treat this as a reference number, not a calibrated probability, same as the site does. Returns an AI-generated summary analysis, conclusion that filters sensationalized language out of recent headlines for a ticker or topic — this is generated live per-request, not pulled from a structured news database, so wording will vary call to call even for the same topic. Without a login token this returns a default basket; with a site-login token query param it personalizes to that user's actual watchlist. Returns suggested allocation weights per ticker based on each ticker's real market score — not equal-weighted, not user-set. Which one should you actually build on? If you're evaluating XFINLAB as a data provider for something you'll maintain long-term, start with the 3 🔑 endpoints — those are the ones with a documented contract and a reason to expect they won't move under you. The 6 🌐 endpoints are genuinely useful for quick scripts and one-off research, and I'm not hiding them, but they're free-tier site plumbing, not a product commitment. Free API key no card, instant : https://www.xfinlab.com/intelligence-api.html https://www.xfinlab.com/intelligence-api.html Repo SDKs + MCP server source : https://github.com/lnanology/Xfinlab https://github.com/lnanology/Xfinlab Curious what other free-tier financial APIs people here have built — what's your split between "documented product" vs "free site tooling"?