The studio
A very small studio and its foxes.
HearthByte builds design tools for working humans and their agents. Built in the open, shipped with intention.
The short version
HearthByte is an indie software studio building tools for developers who work with AI agents.
We started with a question: what if design tools were built for machines to use, not just humans to click? The result is Ensemble — a deterministic, API-first toolkit that agents can call directly.
No screenshots. No copy-paste. Structured data in, design system out.
Tools your agent can use are tools you can trust it with.
What we're building
Developers are no longer the only ones writing code. Agents call APIs, generate assets, and ship features — but most tools still assume a human clicking buttons and reading screens.
We build for both:
- Agent-native tools that speak structured data, not pixels
- Deterministic outputs so agents get consistent results
- Human override because collaboration beats delegation
- Open formats you can read, export, and own
How we build
We use AI as a collaborator, not a replacement. Every feature is designed by humans, reviewed by humans, and shipped with intention.
This isn't vibe coding. We understand every line and can explain every choice. The human leads. The AI accelerates.
Ensemble itself is built this way — and this site runs on tokens served by Ensemble's own API. We use what we sell.
What's next
- Live Canvas — watch your agent build; steer when you want
- More toolkits — beyond design, into code generation and deployment
- Local-first AI — your agent, your machine, your data
Get started
Explore Ensemble and see what agent-native design tools can do. The free tools never need an account.