How to validate an API idea before building it

A developer asked the microsaas community how to check if their API idea has real demand before spending months building it. This is a common challenge for solo founders who want to avoid wasting effort on something nobody needs. The thread surfaces practical, low-cost ways to test an idea early.

Before writing a single line of code, solo founders benefit from confirming that real people would actually pay for what they plan to build. This process is called validation — and skipping it is one of the most common reasons small products fail.

The r/microsaas community is a go-to place for early-stage indie builders to swap advice. Common validation approaches discussed include reaching out directly to potential customers, setting up a simple landing page to collect sign-ups, or running a 'fake door' test — presenting the offer as if it exists and measuring interest before building anything real.

Key points

  • Talk to potential customers directly before writing any code — even a few conversations reveal if the problem is real
  • A simple landing page with a sign-up form lets you measure interest with hard numbers
  • A 'fake door' test means acting as if the product exists to see if people bite — before building it
  • Communities like r/microsaas give fast, honest feedback on early-stage ideas
  • Validating early saves months of work on something the market doesn't want

Quick term guide

microsaas
A small software service built and run by one person or a tiny team, focused on solving a very specific problem
solo founder
A single person who builds and runs a product or business without co-founders
founders
People who are starting or running their own business or project.
founder
A person who starts a new company or project.
surface
Here it means a distinct channel or interface where users encounter information, such as a search results page or an AI chat answer.
validation
Checking whether real people understand, want, or would use an idea before spending more time on it.
landing page
The first page a visitor sees after clicking an ad, link, or campaign message.
feedback
A response that tells a user what they did well or should fix.
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