Building software · Codex

Build simple in-house tools for property offers and deal tracking

Idea + starter prompt, not run by us yet

For: Property investors and rental owners who want tools shaped to how their team works

Using Codex, a rental property owner made internal tools the team relies on daily. They named a tool for working out offer prices during calls, a property report builder that uses field photos, and a tracker for deals under contract. The post describes daily use but gives no build steps or measured results.

Steps

1. Pick the one daily task that wastes the most time, such as working out an offer price.
2. Write down the inputs, the formula you use today and what the output should look like.
3. Paste the starter prompt into Codex and build a small first version.
4. Test it on three past deals where you already know the right answer.
5. Only then share it with the team and add the next tool.

Starter prompt

Build a small internal tool for my property business. The task: [for example, work out an offer price during a call].

Inputs I have: [list inputs]. How I calculate it today: [describe your rule]. What I want to see: [output].

First show me a plan and a sketch of the screen. Build it to run locally with fake sample data. Then I will test it against [number] past deals. Do not connect to any outside service yet, and do not ask me for any passwords.

Original post: Reddit · found via agentusecases.ai. Written up in our own words. We haven't run it, so test it on made-up data first.