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NativeLink uses JSON5 configuration files to define stores, schedulers, servers, and workers. The configuration file (*.json5) is passed to NativeLink at startup.

​
File Format

Configuration files use JSON5 format, which supports:
  • Comments (// and /* */)
  • Trailing commas
  • Unquoted keys
  • Environment variable expansion with ${VAR} or ${VAR:-default}

​
Root Structure

A NativeLink configuration file has the following top-level fields:
​
stores
array
required
List of store configurations. Each store must have a unique name field.
stores: [
  {
    name: "MY_STORE",
    memory: {
      eviction_policy: { max_bytes: "1gb" }
    }
  }
]
​
schedulers
array
List of scheduler configurations. Required for remote execution.
schedulers: [
  {
    name: "MAIN_SCHEDULER",
    simple: {
      supported_platform_properties: {
        cpu_count: "minimum"
      }
    }
  }
]
​
servers
array
required
List of server configurations. At least one server is required.
servers: [
  {
    name: "public",
    listener: {
      http: { socket_address: "0.0.0.0:50051" }
    },
    services: { /* ... */ }
  }
]
​
workers
array
List of worker configurations. Required for remote execution.
workers: [
  {
    local: {
      worker_api_endpoint: { uri: "grpc://127.0.0.1:50061" },
      cas_fast_slow_store: "WORKER_STORE",
      work_directory: "/tmp/work"
    }
  }
]
​
global
object
Global configuration options.

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Environment Variables

NativeLink supports shell expansion in configuration values: 
{
  bucket: "${S3_BUCKET}",
  region: "${AWS_REGION:-us-east-1}",
  max_bytes: "${MAX_SIZE:-10gb}"
}

​
Data Size Format

Size values accept human-readable formats:
  • Raw bytes: 1024
  • Kilobytes: 10kb or 10KiB
  • Megabytes: 100mb or 100MiB
  • Gigabytes: 5gb or 5GiB
  • Terabytes: 1tb or 1TiB

​
Duration Format

Duration values are specified in seconds unless otherwise noted:
  • Seconds: 30 or 30s
  • Minutes: 5m (converted to seconds)
  • Hours: 1h (converted to seconds)

​
Store References

Stores are referenced by name throughout the configuration: 
{
  stores: [
    { name: "CAS_STORE", /* ... */ },
    { name: "AC_STORE", /* ... */ }
  ],
  servers: [{
    services: {
      cas: [{ cas_store: "CAS_STORE" }],
      ac: [{ ac_store: "AC_STORE" }]
    }
  }]
}

​
Validation

NativeLink validates configuration at startup:
  • Store names must be unique
  • Referenced stores must exist
  • Referenced schedulers must exist
  • At least one server must be configured
  • Worker stores must be fast_slow type with filesystem as fast store

​
Example Configuration

{
  stores: [
    {
      name: "CAS_STORE",
      filesystem: {
        content_path: "/var/cache/nativelink/cas",
        temp_path: "/var/cache/nativelink/tmp",
        eviction_policy: { max_bytes: "10gb" }
      }
    }
  ],
  servers: [
    {
      listener: {
        http: { socket_address: "0.0.0.0:50051" }
      },
      services: {
        cas: [{ cas_store: "CAS_STORE" }],
        bytestream: [{ cas_store: "CAS_STORE" }]
      }
    }
  ]
}

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