I rebuilt a failed SaaS as a free API in one day, here's what changed

#backend #api #node #saas

A year ago I built a tool called RespAi. It was an API testing app with AI-powered response analysis, basically Postman but with an AI layer that explained why your API responded the way it did.

It failed immediately. I was competing directly with Postman which has millions of users and brand recognition I'll never touch. Classic mistake.

But the core idea was solid. Developers waste real time manually reading through cryptic 4xx and 5xx responses trying to figure out what went wrong. That problem didn't go away just because my first product failed.

So yesterday I stripped it down to its simplest possible form and shipped it as a single API endpoint.

What Inspekt does

You send it a request. It proxies it to your target URL and returns two things:

The raw response from the API you're testing
A structured AI analysis of what happened and why

The analysis looks like this:

{
"summary": "POST request to Google's homepage returned 405 Method Not Allowed because the root URL does not support POST.",
"status": {
"code": 405,
"meaning": "Method Not Allowed",
"expected": false
},
"diagnosis": "The root endpoint '/' is configured for GET requests only.",
"issues": ["HTTP method mismatch: POST used instead of GET"],
"fixes": ["Change the request method to GET"],
"headers": {
"security_flags": ["x-powered-by header exposes server stack"]
},
"severity": "warning"
}

Why an API and not a GUI tool

Because developers already have Postman for GUI testing. What they don't have is something they can call programmatically, from a script, a CI pipeline, a monitoring job that gives them an intelligent explanation of what went wrong without manual inspection.