lancache

A LAN cache for Steam games.

Features

✅ Allows caching of specific games

✅ Saves cached files as-is without slicing for visibility and easier maintenance

✅ Provides useful cache metrics in Prometheus format

✅ Lightweight image size (~10MB)

Usage

1. Run the app (via docker compose, for example):

services:
  lancache:
    image: ghcr.io/t-richards/lancache:latest
    env:
      # - APP_ENV=production # (optional) set to "development" for colorful console output
      # - BYPASS_CACHE=true # (optional) bypass cache for troubleshooting
    ports:
      - "80:80"
      - "9090:9090" # (optional) prometheus metrics
    volumes:
      - /path/to/cache:/opt/cache
      - /path/to/lancache.toml:/opt/lancache.toml

Note

The cache directory must be writable by the container. The container runs as the app user with UID/GID 1234.

2. Set a DNS record for lancache.steamcontent.com pointing to the host running the app.

Note

Steam will reject your LAN cache if the response TTL is too high. Additionally, some DNS resolvers will still return public AAAA records even if you override the A record for a given hostname. We suggest using the following CNAME -> A configuration for best results.

$ dig lancache.steamcontent.com
<snip>
;; ANSWER SECTION:
lancache.steamcontent.com.   5     IN      CNAME   lancache.lan.
lancache.lan.              600     IN      A       192.168.1.121

Configuration

# File: /opt/lancache.toml

[steam]
# array(uint32): Which depots to cache.
# You can find the relevant IDs for depots on https://steamdb.info/
depots = [
  123, # Leave yourself a note about which game this is
  456, # ...or not, up to you.
]

# boolean: Default false.
# When true, the `depots` setting is ignored and all depots are cached.
cache_all = false

See also: a complete example lancache.toml.

Contributing

Requirements:

• Go =1.25

# Build
make

# Run
bin/lancache

License

Copyright (c) 2025 Tom Richards. All rights reserved.