Version metadata

The version metadata binding can be used to access metadata associated with a version from inside the Workers runtime.

Worker version ID, version tag and timestamp of when the version was created are available through the version metadata binding. They can be used in events sent to Workers Analytics Engine or to any third-party analytics/metrics service in order to aggregate by Worker version.

To use the version metadata binding, update your Worker's Wrangler file:

wrangler.jsonc

{
  "version_metadata": {
    "binding": "CF_VERSION_METADATA"
  }
}

wrangler.toml

[version_metadata]
binding = "CF_VERSION_METADATA"

Interface

An example of how to access the version ID and version tag from within a Worker to send events to Workers Analytics Engine:

JavaScript

export default {
  async fetch(request, env, ctx) {
    const { id: versionId, tag: versionTag, timestamp: versionTimestamp } = env.CF_VERSION_METADATA;
    env.WAE.writeDataPoint({
      indexes: [versionId],
      blobs: [versionTag, versionTimestamp],
      //...
    });
    //...
  },
};

TypeScript

interface Environment {
  CF_VERSION_METADATA: WorkerVersionMetadata;
  WAE: AnalyticsEngineDataset;
}

export default {
  async fetch(request, env, ctx) {
    const { id: versionId, tag: versionTag } = env.CF_VERSION_METADATA;
    env.WAE.writeDataPoint({
      indexes: [versionId],
      blobs: [versionTag],
      //...
    });
    //...
  },
} satisfies ExportedHandler<Env>;