Buildfarm

Spec sheet

Purpose

Buildfarm implements the Remote Execution API for remote caching and execution.Read 5 Oct 2026 · buildfarm.github.io

Product

Buildfarm is a software stack implementing the Remote Execution API for remote content storage, action-result caching, and asynchronous action execution.Read 5 Oct 2026 · buildfarm.github.io

Deployment

The project documents running Buildfarm server and worker processes, using containers for a minimal cluster, and installing an OCI bundled Helm chart.Read 5 Oct 2026 · buildfarm.github.io

Security

The authentication guide describes configuring client/server authentication with self-signed TLS certificates.Read 5 Oct 2026 · buildfarm.github.io

Support

The project repository directs users to file bugs or feature requests as issues and ask questions in the build team Slack channel.Read 5 Oct 2026 · github.com

License

The project repository identifies its license as Apache-2.0.Read 5 Oct 2026 · github.com

Architecture

Workers can perform execution and CAS shard roles, and either role can be disabled in configuration.Read 5 Oct 2026 · buildfarm.github.io

Backplane dependency

Buildfarm requires a backplane for information shared between cluster members, and its quick start uses Redis for that role.Read 5 Oct 2026 · buildfarm.github.io

Backplane requirement

Buildfarm requires a backplane for information shared between cluster members, and the quick start uses Redis.Read 5 Oct 2026 · buildfarm.github.io

Build system compatibility

The project says it is compatible with Bazel, Buck2, Pants, and other build systems that support the API.Read 5 Oct 2026 · github.com

Build systems

The project says it is compatible with Bazel, buck2, Pants, and other build systems that use the Remote Execution API.Read 5 Oct 2026 · github.com

Caching and execution

A Buildfarm cluster can provide Action Cache and Content Addressable Storage for remote caching, and workers can execute build actions remotely.Read 5 Oct 2026 · buildfarm.github.io

CAS features

Documented features include configurable instances, progressive and flow controlled CAS reads and writes, pluggable external CAS endpoints, and RequestMetadata attribution.Read 5 Oct 2026 · buildfarm.github.io

CAS options

Buildfarm documents in-memory storage, an external CAS proxy, an HTTP/1 proxy, and persistent worker disk storage as CAS implementations.Read 5 Oct 2026 · buildfarm.github.io

Deployment scale

The quick start says deployments can spread servers and workers across machines and describes use by hundreds or thousands of developers or CI processes.Read 5 Oct 2026 · buildfarm.github.io

Execution controls

Execution policies can modify or control worker actions, including wrapper policies such as running actions through the Linux sandbox or as the nobody user.Read 5 Oct 2026 · buildfarm.github.io

Experimental limitation

The worker documentation says FuseCAS is experimental and may not work reliably over long periods or under substantial load.Read 5 Oct 2026 · buildfarm.github.io

Feature support

The project lists configurable instances, progressive and flow-controlled CAS reads and writes, pluggable external CAS endpoints, and RequestMetadata behavior attribution among its supported features.Read 5 Oct 2026 · buildfarm.github.io

Metrics

The quick start documents a Prometheus metrics endpoint configurable for the server and worker.Read 5 Oct 2026 · buildfarm.github.io

Notable limitation

The worker documentation says the Fuse execution filesystem is experimental and may be unreliable under substantial load.Read 5 Oct 2026 · buildfarm.github.io

Resource limits

Workers can use Linux cgroups to limit execution resources, and the documentation says this feature requires OS-specific cgroups support available in Linux.Read 5 Oct 2026 · buildfarm.github.io

Sandboxing

Configuration can require actions to use a sandbox, and supports settings for cgroups and an as-nobody wrapper.Read 5 Oct 2026 · buildfarm.github.io

Scale

The quick start says deployments can spread services across machines and may serve hundreds or thousands of developers or CI processes.Read 5 Oct 2026 · buildfarm.github.io

Setup

The quick start demonstrates running the service on Linux and provides a container-based startup option.Read 5 Oct 2026 · buildfarm.github.io

Storage options

Buildfarm documents in-memory, external gRPC, HTTP/1 proxy, persistent worker disk, and sharded CAS implementations.Read 5 Oct 2026 · buildfarm.github.io

Worker roles

Workers can perform execution, serve as CAS shards, or do both; a worker requires local filesystem storage.Read 5 Oct 2026 · buildfarm.github.io

Where Specifiction places it

• Build Cache Software#11 of 237.8