Chai Discovery

weights

open(downloaded automatically by the chai-lab package and covered by the repository's Apache-2.0 grant)

data

closed(training data not released

code

partial(inference CLI and feature-context API

license

Apache-2.0(OSI)

The repository license is Apache-2.0, which on its own would say nothing about the weights, and the check that matters here is that the README extends the same grant to them in as many words. Chai-1 is therefore commercially usable weights on a closed corpus, which is the category's centre of gravity.

• https://raw.githubusercontent.com/chaidiscovery/chai-lab/main/README.md recorded 2026-09-10

  "Chai-1 is released under an Apache 2.0 License (both code and model weights), which means it can be used for both academic and commerical purposes, including for drug discovery"; weights are downloaded automatically into the package directory; the package runs inference only.

• https://raw.githubusercontent.com/chaidiscovery/chai-lab/main/LICENSE recorded 2026-09-10

  Apache License Version 2.0 body, Copyright 2024 Chai Discovery.

• https://api.github.com/repos/chaidiscovery/chai-lab recorded 2026-09-10

  license spdx_id: Apache-2.0; archived: false; fork: false; no training entry point in the published surface.