Installation

build-depends: nova-cache

The compression flag (on by default) requires the system liblzma. Build with -f-compression if you only need hashing, NAR, or narinfo.

Usage

import NovaCache.Hash (hashBytes, formatNixHash)
import qualified Data.ByteString as BS

-- Hash file contents into sha256:<nix-base32>
hash <- formatNixHash . hashBytes <$> BS.readFile path

import NovaCache.NarInfo (parseNarInfo)
import NovaCache.Signing (parseSecretKey, sign)

-- Parse a narinfo and sign it
case (parseNarInfo raw, parseSecretKey "mykey:base64...") of
  (Right ni, Right sk) -> print (sign sk ni)  -- Right "mykey:<base64 sig>"
  _                    -> error "parse failed"

import NovaCache.Validate (validateFull)

-- Validate an upload: fields + NAR hash + file hash + signatures.
-- Pure, and every error is collected rather than failing on the first.
case validateFull publicKey ni narBytes fileBytes of
  Right ()  -> accept
  Left errs -> reject errs

Server

cabal run --flag server nova-cache-server -- --port 5000 --store ./nix-cache

Configuration

Endpoints

Public cache

A public instance runs at cache.novavero.ai:

extra-substituters = https://cache.novavero.ai
extra-trusted-public-keys = cache.novavero.ai-1:2yJK0UZWlDDTpThzEdqfGWaj+j3ljOCGoA50Ims47dM=

CI cache seeding

A composite action pushes store paths to a nova-cache server from CI. It resolves runtime paths via nix-build, diffs against the server's /narinfo-hashes, and uploads only what is missing.

- uses: Novavero-AI/nova-cache/.github/actions/seed@main
  with:
    cache-url: https://cache.example.com
    api-key: ${{ secrets.CACHE_API_KEY }}

Inputs: cache-url and api-key (required); paths and parallel (optional).

Build & test

cabal build
cabal test

Optional flags: -f-compression skips the liblzma dependency, and --flag server builds the cache server. Requires GHC 9.8+ and cabal-install 3.10+.

_{BSD-3-Clause · Novavero AI}