When generating code is cheap, correctness has to be checkable. arcanist.sh builds the Haskell tools that make it so, in Rust and in public: a fast toolchain, a compiler built to check everything it can, and a registry where verification accumulates.
hx · the whole Haskell toolchain in one fast binary
Installs GHC and Cabal, builds, tests, formats and lints, pins every dependency by hash, and publishes packages. It drives GHC and Cabal rather than replacing them, and gives AI agents the same commands over MCP.
curl -fsSL https://arcanist.sh/hx/install.sh | sh
hx init my-app && cd my-app && hx run- 5.6× faster cold builds than cabal, measured
- Lockfiles that pin sources by SHA-256;
--lockedfor CI - Workspaces,
hx install, coverage, profiling, publishing, managed GHC and bhc toolchains
bhc · the Basel Haskell Compiler
A clean-slate compiler for the Haskell you already write, in beta. Native code through LLVM, WebAssembly for WASI, and a runtime profile chosen per build. Type classes are elaborated into explicit dictionaries, so every definition's meaning is spelled out.
- All 221 modules of Pandoc type-check and compile; its Markdown reader and HTML writer run
- 236 / 243 WebAssembly fixtures byte-identical to native
- Where bhc stands, measured, with the caveats
registry · packages, signed and checked
A Haskell package repository plain cabal reads next to Hackage, signed with hackage-security. hx publishes to it, and the bhc verifier builds every new version and records the result beside the package: the first piece of a commons where a check that ran once is recorded instead of repeated.
A checkable toolchain, meaning made explicit, verification that accumulates, and then the commons: definitions named by what they mean and the contract they run under, each carrying a record of what was checked. The reasoning is in the manifesto.
| arcanist.sh | Website and blog |
| docs.arcanist.sh | Documentation for hx and bhc |
| registry.arcanist.sh | Browse the package registry |
| vellum · brutalist-blueprint | The Zola themes behind arcanist.sh and the original bhc site |
| @raskell_io | X |