Hayba
A toolset for rigorous worldbuilding.
What is Hayba?
Hayba is an open-source toolset for building imaginary worlds with the same rigour a working geologist, linguist, or architect would apply to a real one. Tectonics that age right. Conlangs that obey real phonotactics. Cities that follow trade routes. Wired together by an MCP your LLM can drive.
Why now?
World-building tools used to be reference apps — places to write down what you already knew. Hayba inverts that: you describe the constraints, the simulation discovers the world, and the workbench helps you author what the simulation can't infer. LLMs make this loop tight enough to be productive.
Who builds it
A small team based out of zajalist. Currently one developer (Badr) plus the community on GitHub. Built on open standards: PostgreSQL, MCP, PHOIBLE for phonological data, Unreal Engine 5 for the in-engine plugin.
License
The toolset is MIT-licensed. The hosted tier (cloud sync, share-links) is currently waitlist-gated while we shake out the first 50 users. Local tools are free forever and don't require any account.