## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work
> - Published container images are the deployable unit for self-hosted
and managed instances, so merge-to-image latency bounds every deploy
iteration
> - The docker workflow configures BuildKit caching, but builds still
ran ~12+ minutes essentially cold
> - Two causes: the most expensive layer (four CLI toolchains + apt) is
ordered after the always-changing app copy so it can never cache, and
the type=gha cache's 10GB repo cap means the two multi-arch mode=max
jobs evict each other
> - This pull request reorders the tool layer above the app copy (with a
weekly epoch so @latest tools keep advancing) and switches both jobs to
registry-backed cache in ghcr
> - The benefit is that warm builds shrink to roughly the app build +
push, targeting the sub-5-minute range together with the amd64-only
cloud variant
## Linked Issues or Issue Description
No existing public issue — inline description following the feature
request template:
**Subsystem affected**
CI / release publishing (docker workflow, Dockerfile)
**Problem or motivation**
Despite `cache-from/cache-to` being configured, image builds run
effectively cold: (1) the production stage installs four CLI toolchains
+ apt packages *after* `COPY --from=build /app /app`, and since the app
copy changes every commit, that most-expensive layer rebuilds every
build, per arch; (2) the `type=gha` BuildKit cache is capped at 10GB per
repository, and two multi-arch `mode=max` jobs overflow and evict each
other's entries.
**Proposed solution**
Order the tool/OS layer before the app copy (it references nothing from
`/app`), refresh it weekly via a `CLI_TOOLS_CACHE_EPOCH` build arg so
the `@latest` tools don't freeze in the cache, and move both jobs to
registry-backed BuildKit cache (`:buildcache` / `:buildcache-cloud` refs
in ghcr, no size cap, separate refs so the parallel jobs don't clobber
each other).
**Alternatives considered**
Pinning CLI tool versions instead of the weekly epoch — more
deterministic, but adds a version-bump chore; the weekly epoch preserves
current freshness semantics with bounded staleness. Keeping type=gha
with `mode=min` — smaller cache but loses intermediate-stage reuse,
which is where most of the win is.
**Roadmap alignment**
Not on ROADMAP.md; CI/publishing speed improvement only.
## What Changed
- `Dockerfile`: the production stage's tool/OS `RUN` (npm --global CLIs,
apt, `/paperclip` setup) moves above `COPY --from=build /app /app`; new
`CLI_TOOLS_CACHE_EPOCH` arg consumed by that layer. The `cloud` stage is
unaffected — it only layers plugin dists on top of the finished
production stage.
- `.github/workflows/docker.yml`: both jobs stamp the ISO week into
`CLI_TOOLS_CACHE_EPOCH`, and both switch `cache-from/cache-to` from
`type=gha` to `type=registry` with per-job refs.
- Includes the one-line amd64-only cloud-variant commit from #10570 so
the two PRs can't conflict; if #10570 merges first, this PR rebases down
to a single commit automatically.
## Verification
- Image content is unchanged by layer reordering: the moved `RUN`
references nothing from `/app`, and Docker layer ordering only affects
caching, not the final filesystem (tool installs and app copy touch
disjoint paths).
- The cache ref is written only by this workflow — `docker.yml` runs on
master/tag pushes, never on PRs — so the workflow's existing "no shared
caches into build inputs" supply-chain stance is unchanged (BuildKit
layer cache was already accepted via type=gha; the registry backend has
the same writer trust).
- Runtime proof lands with the first two master builds after merge: the
first warms the cache, the second should show the tool layer and
deps/build stages as CACHED in the build log, with wall clock dropping
accordingly. I'll be watching those as part of managed-deploy work.
## Risks
- Low. Worst case the registry cache misses (cold-build behavior, same
as today). The weekly epoch means CLI tools update at most a week late
inside images; a release built mid-week ships the tools from that week's
first build. Cache refs add two small artifacts to ghcr.
## Model Used
Claude Fable 5 (`claude-fable-5`, extended thinking, via Claude Code
with tool use and code execution).
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass (no test-affecting changes)
- [x] I have added or updated tests where applicable (n/a — build config
and layer ordering only)
- [x] I have updated relevant documentation to reflect my changes
(in-file comments document both mechanisms)
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
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