Claude Opus 4.8

Explain what an API is to someone who has never written code. Do not use a restaurant or waiter analogy. Plain prose only — no headings, bullet points, or markdown formatting. Maximum 50 words.

An API is a set of rules that lets two programs talk to each other. One program requests something specific, and the other sends back exactly what was asked for, without either needing to know how the other works inside.

A two-person startup is deciding whether to build their own user authentication or use a hosted provider. Give them a clear recommendation, then the single strongest argument against your own recommendation. Plain prose only — no headings, bullet points, or markdown formatting. Maximum 150 words.

Use a hosted provider like Auth0, Clerk, or Supabase Auth. As a two-person team, your scarcest resource is engineering time, and authentication is a deep, unglamorous problem full of security landmines: password hashing, session management, token rotation, account recovery, breach detection, and eventually multi-factor and social login. A hosted provider gives you all of this immediately, maintained by specialists who handle vulnerabilities you'll never hear about. Every hour you don't spend building login is an hour spent on the product that actually differentiates you. Ship faster, sleep better. The strongest argument against this: you're handing a critical dependency and your users' identity data to a third party whose pricing, reliability, and continued existence you don't control. Providers have been known to raise prices sharply once you're locked in, and migrating authentication later is genuinely painful. If your economics or scale make that lock-in dangerous, owning it earlier may be wiser.