Cache Service

This service lets your plugin interact with a cache. It is bound to your plugin too, so that you will only set and get values in your plugin's private namespace.

Configuration

The cache service can be configured using the backend.cache section in your app-config.yaml:

backend:
  cache:
    store: redis # or 'valkey', 'memcache', 'memory'
    connection: redis://localhost:6379

    # Store-specific configuration (Redis/Valkey only)
    redis:
      client:
        # Optional: Global namespace prefix for all cache keys
        namespace: 'my-app'
        # Optional: Separator used between namespace and plugin ID (default: ':')
        keyPrefixSeparator: ':'
        # Other Redis-specific options...
        clearBatchSize: 1000
        useUnlink: false

Namespace Configuration

For Redis and Valkey stores, you can configure a global namespace that will be prefixed to all cache keys:

• Without namespace: Cache keys use only the plugin ID (e.g., catalog:some-key)
• With namespace: Cache keys use the format namespace:pluginId:key (e.g., my-app:catalog:some-key)

The keyPrefixSeparator controls what character is used between the namespace and plugin ID (defaults to :).

Note: Memory and Memcache stores do not support namespace configuration and will always use the plugin ID directly.

Using the service

The following example shows how to get a cache client in your example backend plugin and setting and getting values from the cache.

import {
  coreServices,
  createBackendPlugin,
} from '@backstage/backend-plugin-api';

createBackendPlugin({
  pluginId: 'example',
  register(env) {
    env.registerInit({
      deps: {
        cache: coreServices.cache,
      },
      async init({ cache }) {
        const { key, value } = { key: 'test:key', value: 'bob' };
        await cache.set(key, value, { ttl: 1000 });

        // .. some other stuff.

        await cache.get(key); // 'bob'
      },
    });
  },
});