# halo2_proofs [](https://crates.io/crates/halo2_proofs) #
## [Documentation](https://docs.rs/halo2_proofs)
## Minimum Supported Rust Version
Requires Rust **1.60** or higher.
Minimum supported Rust version can be changed in the future, but it will be done with a
minor version bump.
## Controlling parallelism
`halo2_proofs` currently uses [rayon](https://github.com/rayon-rs/rayon) for parallel
computation. The `RAYON_NUM_THREADS` environment variable can be used to set the number of
threads.
You can disable `rayon` by disabling the `"multicore"` feature.
Warning! Halo2 will lose access to parallelism if you disable the `"multicore"` feature.
This will significantly degrade performance.
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.