Z.ai GLM-5.3

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 different software programs communicate. When you check the weather in an app, the app requests data through the API, the weather service responds, and the app displays it. It's a standardized way programs exchange information without knowing each other's inner workings.

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 Clerk or Supabase Auth. Authentication looks like a weekend project, but the actual surface area—password resets, email verification, OAuth flows, session management, 2FA—consumes weeks, and a security mistake can destroy a young company's credibility permanently. For two founders, engineering time is your scarcest asset, and auth is undifferentiated plumbing that customers never notice unless it breaks. Buying it lets you spend your limited hours on the product insight that justified the startup existing. The strongest argument against: you're chaining your most critical dependency to a third party whose outage, pricing hike, acquisition, or policy change instantly becomes yours, and every account created deepens the lock-in, making eventual migration genuinely painful. You're trading a bounded, one-time build cost for a permanent, unbounded dependency risk you can't fully control.