Silo

What Silo is

Silo is an open-source, self-hosted HTTP server for remote Gradle build caching. It implements the Gradle cache protocol’s GET, PUT and HEAD methods, allowing Gradle clients to retrieve, upload and check cached artifacts. The project is designed as a replacement for the end-of-life Gradle Remote Build Cache Node. Silo runs on Linux, requires JVM 21 or later, and is delivered either as a fat JAR or as a multi-architecture Docker image for linux/amd64 and linux/arm64. Filesystem storage is available now, while S3 and GCS are listed as roadmap work. Cache administration includes least-recently-used eviction, time-to-live rules, byte and entry limits, and reserved free-space thresholds. Authentication supports HTTP Basic and OIDC/Bearer with read-only or read-write role mapping. Operators get Prometheus metrics, JSON-structured logs, health and readiness endpoints, a live statistics stream and a single-page dashboard at /admin. The project states that it has no phone-home telemetry or accounts, supports atomic writes with crash recovery, and publishes cosign-signed releases with checksums and CycloneDX SBOMs. Silo is free under Apache-2.0 and describes its current status as alpha and pre-1.0.

Who it suits

Silo suits teams running Gradle builds that want to host their own remote cache on Linux. It is aimed at operators comfortable with JVM 21, Docker or JAR deployment, authentication configuration and filesystem administration.

Limits

The free plan is self-hosted and currently provides filesystem storage. S3, GCS, compression and replication are described as open work, and the project is pre-1.0 with security fixes limited to the latest v0.x release.

Getting started

1. Open the Silo GitHub website
2. Choose the fat JAR or Linux Docker image for your architecture
3. Provide a JVM 21-or-later environment when using the JAR
4. Configure filesystem storage and cache policies
5. Set HTTP Basic or OIDC/Bearer roles
6. Connect Gradle clients to the Silo HTTP cache

Verdict

Pick Silo if you need a free, self-hosted Gradle remote cache with configurable access, eviction and monitoring. Look elsewhere if you require available S3 or GCS backends, compression or replication, or prefer a product beyond alpha status.