Skip to main content

​
Overview

When you run jobs on Blacksmith, all official GitHub and popular third-party cache actions transparently interact with our 4x faster, colocated cache, instead of GitHub’s backend. Zero code changes are required. 
    # If it's running on Blacksmith, it will use our cache
    name: Cache Cargo dependencies
    uses: actions/cache@v4
Currently, the Rust sccache and the GitHub Actions cache option in the docker/build-push-action are still redirected to GitHub’s backend. For 40x faster Docker builds, please use our Blacksmith Docker actions. For more information, refer to the Docker builds page.

​
Basics

GitHub’s cache action stores artifacts in Azure Blob Storage. When your runner isn’t in the same availability zone, downloads are often slow and unreliable. Blacksmith fixes this by storing cache artifacts in the same datacenter as your runners. Our approach removes network latency and almost saturates the NIC. As a result, your downloads complete around 4x faster, with no code changes required.

​
Branch Protected Caches

When using our colocated cache, each cache entry will be scoped to its branch or tag to ensure cache entries are only accessible to the appropriate workflow runs. This enhances the security of our cache offering by creating a logical boundary between cache artifacts. These access restrictions are consistent with GitHub’s implementation. If you would rather share cache artifacts across branches in a repository, you can toggle this feature off in the settings page of your Blacksmith dashboard.

​
Opt out

If you’d rather not use our cache for any reason, just let us know by opening a support ticket and we’ll disable it for you.

​
Pricing

There is no additional cost for using our cache. For all other pricing, please visit our pricing page.

​
FAQ

By default, we provide 25GB of free storage per repo per week, a substantial increase from GitHub’s 10GB to maximize your cache hits.
If you’d like us to increase the allowed cache size for your organization, contact us at [email protected].
Like GitHub, our cache evicts the least recently used cache entries that were last accessed more than 7 days ago.
Yes. Actions cache V1 has been deprecated. Please move to the newest approach.
The following content describes the legacy approach of using Blacksmith-specific cache actions. This approach is now deprecated in favor of our new cache described above. Our new cache requires no code changes and automatically works with GitHub’s native cache actions.The forks will no longer be updated by Blacksmith, so we recommend migrating workflows to the upstream version of the action.
This cache is a drop-in replacement for GitHub’s cache action. Blacksmith’s cache co-locates cache artifacts in the same datacenter park as the bare metal instances running our VMs, and can almost saturate the NIC on our runners. GitHub’s cache action stores cache artifacts in Azure Blob Storage, which generally performs poorly when the action runner is not co-located in the same AZ as the storage. This results in ~4x faster cache download speeds compared to GitHub’s cache.Migrating from the actions/cache to the Blacksmith cache is a one line change. Simply replace the actions/cache@v3 line in your workflow files with useblacksmith/cache@v5.
    name: Cache dependencies
-   uses: actions/cache@v3
+   uses: useblacksmith/cache@v5
If you’re using actions/cache/save and actions/cache/restore, you can migrate them to useblacksmith/cache/save and useblacksmith/cache/restore respectively.For more information, refer to GitHub’s official documentation, since the Blacksmith cache is fully compatible with GitHub’s cache.

​
Language specific cache actions

In addition to the useblacksmith/cache, the Blacksmith cache also provides drop-in replacements for GitHub’s official actions/setup-* actions. These replacements have the same semantics as the official setup actions, but they are backed by Blacksmith’s much faster and more reliable cache.
        name: Setup go
-       uses: actions/setup-go@v4
+       uses: useblacksmith/setup-go@v6
        with:
          go-version: '>=1.17.0'
Please refer to the README of each setup action for detailed instructions on how to configure them. For languages that we don’t have a setup action for, you can still leverage the useblacksmith/cache action to cache dependencies by following these guidelines.Some languages have popular cache actions that are not maintained by GitHub. The Blacksmith cache offers drop-in replacements for these actions too so that you can leverage our faster cache.
  • Rust
  • Gradle
  • Zig
  • Bazel
The Blacksmith cache offers a drop-in replacement for Swatinem/rust-cache@v2. Once you make the changes outlined below, you can configure the action using these guidelines.
    name: Setup rust cache
-       uses: Swatinem/rust-cache@v2
+       uses: useblacksmith/rust-cache@v3
As our customers migrate to Blacksmith, we keep growing our list of cache actions that are compatible with Blacksmith’s cache.
  • golangci-lint-action
    name: Run lint
-       uses: golangci/golangci-lint-action@v6
+       uses: useblacksmith/golangci-lint-action@v6

​
Using the Blacksmith cache inside a container

If your GitHub Actions job runs inside a container, you will need to ensure that the container is hydrated with certain Blacksmith specific environment variables. These environment variables allow the container to upload and download artifacts from Blacksmith’s cache.To do this, you can add an env section to your container definition as shown below.
  container:
      image: mcr.microsoft.com/playwright:v1.41.1
+     env:
+       BLACKSMITH_CACHE_TOKEN: ${{ env.BLACKSMITH_CACHE_TOKEN }}
+       BLACKSMITH_CACHE_URL: ${{ env.BLACKSMITH_CACHE_URL }}
+       GITHUB_REPO_NAME: ${{ env.GITHUB_REPO_NAME }}
If the container image does not have tar installed, you will need to install it as a step inside the container. tar is required to extract the artifacts downloaded from Blacksmith’s cache.
  steps:
      - name: Install GNU tar
        run: |
          apk add --no-cache tar
Without these steps, you will see a 401 error or an Unauthenticated error when restoring or saving to the Blacksmith cache.
⌘I