Buildless vs Harmonia

Buildless is a remote build cache service for teams that want build tools to reuse compiled output rather than repeat compilations. It supports Gradle, Maven, Turborepo, Bazel, CCache, and SCCache, with the maker describing its main integrations as drop-in and requiring no changes to code, the build process, or cloud setup. The docs also list REST/gRPC, Redis (RESP), and GitHub Actions. Its described infrastructure combines Cloudflare edge routing with a Redis-compatible backend through Dragonfly Cloud, plus tunable replication and durable in-memory storage. The Team plan adds premium caching with replication, edge serving, and persistence. Individual / OSS is free, with one project, one user, 3GB of cache, and 100GB transfer. Team is free during the public beta, with five projects, up to 50 users, 10GB cache, and 1TB transfer. Builds are not halted when storage or transfer is exceeded, but overages are charged. Business pricing is TBD and lists private cloud or on-prem options.

Harmonia is free, open-source software for serving a Nix store as a binary cache over HTTP. Written in Rust for Linux self-hosting, it supports HTTP range requests for NAR streaming and streaming build logs. The /serve// endpoint can provide package contents and discover index.html to serve websites directly from the Nix store. Harmonia can transparently compress content with zstd and provide TLS when no frontend web server is used. Documentation covers a NixOS module and nginx HTTPS frontend configuration for a public cache. Narinfo signing is disabled unless private signing-key paths are supplied. Prometheus metrics are available at /metrics, with a Grafana dashboard included in the repository. Since version 3.1.0, metadata is read directly from db.sqlite without a nix-daemon connection. Version 3.3.0 adds harmonia-gc for removing store garbage while nix-daemon builds. It uses the MIT License.