Attic is a self-hostable Nix Binary Cache server backed by an S3-compatible storage provider. It has support for global deduplication and garbage collection.

Attic is still an early prototype and is looking for more testers. Want to jump in? Start your own Attic server in 15 minutes.

⚙️ Pushing 5 paths to "demo" on "local" (566 already cached, 2001 in upstream)...
✅ gnvi1x7r8kl3clzx0d266wi82fgyzidv-steam-run-fhs (29.69 MiB/s)
✅ rw7bx7ak2p02ljm3z4hhpkjlr8rzg6xz-steam-fhs (30.56 MiB/s)
✅ y92f9y7qhkpcvrqhzvf6k40j6iaxddq8-0p36ammvgyr55q9w75845kw4fw1c65ln-source (19.96 MiB/s)
🕒 vscode-1.74.2        ███████████████████████████████████████  345.66 MiB (41.32 MiB/s)
🕓 zoom-      ███████████████████████████              329.36 MiB (39.47 MiB/s)


  • Multi-Tenancy: Create a private cache for yourself, and one for friends and co-workers. Tenants are mutually untrusting and cannot pollute the views of other caches.
  • Global Deduplication: Individual caches (tenants) are simply restricted views of the content-addressed NAR Store and Chunk Store. When paths are uploaded, a mapping is created to grant the local cache access to the global NAR.
  • Managed Signing: Signing is done on-the-fly by the server when store paths are fetched. The user pushing store paths does not have access to the signing key.
  • Scalabilty: Attic can be easily replicated. It's designed to be deployed to serverless platforms like but also works nicely in a single-machine setup.
  • Garbage Collection: Unused store paths can be garbage-collected in an LRU manner.