Provide the write token
Set NIX_CACHE_WRITE_TOKEN in the CI job, or pass --token-file. Keep the token in your CI secret store and never commit it.
export NIX_CACHE_WRITE_TOKEN=<WRITE_TOKEN>
Nix Cache Admin
Connected
Packages
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Versions
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Pinned versions
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Indexed objects
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Indexed bytes
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Packages and versions
Every action below targets a build version. Package rows are grouping and inspection only.
| Package / version | Tags | Files | Bytes | Registered | Retention | Actions |
|---|
Automatic GC retention rules
Define which versions match, how they are grouped, and when automatic garbage collection may remove them.
Deployment settings
Cache-info values, the optional R2 public URL, and default retention are deployment environment variables. Change them with Wrangler and redeploy.
For publishers
CI publishing
Use the Worker URL for publishing. The optional R2 Custom Domain is for anonymous downloads only. Keep the write token in your CI secret store.
Upload through staging
Run bin/nix-cache-upload against the Worker URL. NARs go to temporary private R2 staging keys; the client verifies and promotes them before publishing narinfo.
NIX_CACHE_WRITE_TOKEN=<WRITE_TOKEN> bin/nix-cache-upload --to https://nix-cache.ihc.im --package acme --version ci-123 ./result
Version registration is automatic
The bundled client publishes narinfos and registers the complete package/version declaration automatically. Use the API below only for a manual integration; narinfoKeys lists uploaded narinfo keys, while tags and retentionDays are optional metadata.
curl -X PUT "https://nix-cache.ihc.im/api/packages/acme/versions/2026.08.18" -H "Authorization: Bearer $WRITE_TOKEN" -H "Content-Type: application/json" --data '{
"narinfoKeys": ["abc123.narinfo"],
"tags": { "channel": "stable", "system": "x86_64-linux" },
"retentionDays": 30
}'Registration is idempotent. It is a complete declaration: omitted members and tags are removed from that version.