# Build your own agent harness, even as a side project

- Category: mindset
- Author: Vlad (https://indie.md/people/vlad/)
- Source: https://indie.md/events/indie-tm-7-timisoara-april-2026/
- Canonical URL: https://indie.md/advice/build-your-own-agent-harness/

Most developers assume an agent harness is something you buy or install. In practice, a working harness for your own workflow is a weekend project, not a quarter-long one. The payoff is that every future agentic feature you build sits on primitives you actually control: your own prompt format, your own tool interface, your own logging and trajectory replay. Even if you never ship it as a product, the harness compounds: it is the thing that makes every downstream experiment cheap. And as [Vlad](/people/vlad) put it at the end of his demo, it is genuinely fun to build, which is a signal in itself.