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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

Variable	Description
PORT	Listen port (default: 5000)
NIX_CACHE_DIR	Store directory (default: ./nix-cache)
CACHE_API_KEY	Bearer token required for PUT. The server refuses to start without it unless --allow-open-writes is passed.
SIGNING_KEY_FILE	Ed25519 secret key file for server-side narinfo signing
LOG_REQUESTS	Set to 0 to disable request logging

Endpoints

Method	Path	Description
GET	/	Landing page: live stats and the cache public key
GET	/nix-cache-info	Cache metadata
GET	/narinfo-hashes	All cached narinfo hashes, newline-delimited
GET	/<hash>.narinfo	Fetch a narinfo
GET	/nar/<file>	Fetch a NAR
PUT	/<hash>.narinfo	Upload a narinfo (authenticated, validated)
PUT	/nar/<file>	Upload a NAR (authenticated)

Public cache

A public instance runs at cache.novavero.ai:

extra-substituters = https://cache.novavero.ai
extra-trusted-public-keys = cache.novavero.ai-1:9gQ7tLWMM+2tdC9H5sKMJltDIPfD7X2GWlZe8Aa8hHQ=

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+.

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_{Apache-2.0 - Novavero AI Inc.}