Promptive

A little context: I'm a solo developer who shipped Lease Decoder, an AI powered app that reads rental lease agreements and breaks them down in plain English so renters actually understand what they're signing. Building it was one of the best experiences I've had as a developer. It also exposed a problem I couldn't unsee.

Every time I tweaked a prompt, I had no real way of knowing whether the output got better or worse. I was guessing. A change that felt like an improvement could be quietly degrading results for a specific type of lease and I'd have no idea until something felt off. There were no guardrails. No way to test before shipping. Just vibes and hoping for the best.

I looked for a tool to solve it. Everything I found was built for enterprise teams with budgets and engineers I don't have. So I built Promptive.

What it does

Promptive gives indie developers real visibility into what their LLMs are actually doing at runtime. You can log every prompt and response, track latency and cost across models, version your prompts, and run regression tests before you ship a change so you find out something broke before your users do.

The feature I'm most proud of is the Evals tab. You define a test case with input, expected output, scorer and run it against two models or two prompt versions side by side. It's the part of LLM development that everyone knows they should do and almost nobody does, because there was nothing lightweight enough to make it worth it. I built it because I needed it for Lease Decoder first.

Why it's different

Most observability tools are built top-down designed for scale, then offered to smaller teams as a stripped-down plan. Promptive is built from the bottom up, for the solo builder who is iterating fast, wearing every hat, and needs something that works without a three-hour onboarding call.

I'm not guessing at the problem. I lived it.

Where it is today

Promptive is live and free to try with builder and pro plans with added features and a fraction of the cost of the enterprise tools. I'm building it in public, shipping fast, and genuinely looking for feedback from other indie developers who are building with LLMs.

If that's you I'd love to know what your current setup looks like and whether this solves a real problem for you.

Check it out at promptive.dev