Field notes
Practical guides on market data, Amazon catalog data, live sports feeds — and honest API engineering.
X-Cache: HIT — why our APIs tell you when data is stale
Most APIs hide their caching. Apexon responses carry X-Cache, X-RateLimit headers, and X-Response-Time-ms so you always know how fresh the data is.
Streaming live scores and in-play odds over SSE
The architecture behind LineSnap: a Unix-socket hot path, JSON cold path, change-only SQLite archive, and one SSE stream. Coming soon on apexon.dev.
ASIN lookup in practice
A practical walkthrough of ASIN-based Amazon endpoints: product details, live offers, review pages, and best-seller lists across 22 storefronts.
Amazon product data: scraping vs. using an API
What it really takes to scrape Amazon at scale in 2026 — anti-bot walls, parser drift, proxy costs — and when a hosted product-data API is the saner choice.
Fetching a full options chain with one REST call
How to pull a complete options chain — calls, puts, strikes, expirations — from a REST API with one request, plus honest caching signals.
Yahoo Finance API in 2026: what still works, what to use instead
The unofficial Yahoo Finance API keeps breaking. Here's what actually works in 2026 — DIY scraping, open-source libraries, and hosted APIs compared.