feat: add redis cache tags utils

README.md

@@ -34,6 +34,69 @@ CREATE TABLE IF NOT EXISTS query_cache_tags (
 );
 ```
 
+### Utilities for DatoCMS Cache Tags (Redis)
+
+The following utilities provide Redis-based alternatives to the Postgres cache tags implementation above. They work with [DatoCMS cache tags](https://www.datocms.com/docs/content-delivery-api/cache-tags) and any Redis instance.
+
+- `redis.storeQueryCacheTags`: Stores the cache tags of a query in Redis.
+- `redis.queriesReferencingCacheTags`: Retrieves the queries that reference cache tags.
+- `redis.deleteCacheTags`: Deletes cache tags from Redis.
+- `redis.truncateCacheTags`: Wipes out all cache tags from Redis.
+
+The Redis connection is automatically initialized on first use using the `REDIS_URL` environment variable.
+
+#### Environment Variables
+
+Add your Redis connection URL to your `.env.local` file:
+
+```bash
+# Required: Redis connection URL
+# For Upstash Redis
+REDIS_URL=rediss://default:your-token@your-endpoint.upstash.io:6379
+
+# For Redis Cloud or other providers
+REDIS_URL=redis://username:password@your-redis-host:6379
+
+# For local development
+REDIS_URL=redis://localhost:6379
+
+# Optional: Key prefix for separating production/preview environments
+# Useful when using the same Redis instance for multiple environments
+REDIS_KEY_PREFIX=prod        # For production
+REDIS_KEY_PREFIX=preview     # For preview/staging
+# Leave empty for development (no prefix)
+```
+
+**Note**: Similar to how the Postgres version uses different table names, use `REDIS_KEY_PREFIX` to separate data between environments when using the same Redis instance.
+
+#### Usage Example
+
+```typescript
+// Recommended: Use namespaces for clarity
+import { generateQueryId, redis } from '@smartive/datocms-utils';
+
+const queryId = generateQueryId(query, variables);
+
+// Store cache tags for a query
+await redis.storeQueryCacheTags(queryId, ['item:42', 'product', 'category:5']);
+
+// Find all queries that reference specific tags
+const affectedQueries = await redis.queriesReferencingCacheTags(['item:42']);
+
+// Delete cache tags (keys will be recreated on next query)
+await redis.deleteCacheTags(['item:42']);
+```
+
+#### Redis Data Structure
+
+The Redis implementation uses Sets to track query-to-tag relationships:
+
+- **Cache tag keys**: `{prefix}{tag}` → Set of query IDs
+
+Where `{prefix}` is the optional `REDIS_KEY_PREFIX` environment variable (e.g., `prod:`, `preview:`).
+
+When cache tags are invalidated, their keys are deleted entirely. Fresh mappings are created when queries run again.
+
 ### Other Utilities
 
 - `classNames`: Cleans and joins an array of inputs with possible undefined or boolean values. Useful for tailwind classnames.

package.json

@@ -25,10 +25,19 @@
     "eslint": "9.39.2",
     "eslint-import-resolver-typescript": "4.4.4",
     "prettier": "3.8.1",
-    "typescript": "5.9.3"
+    "typescript": "5.9.3",
+    "ioredis": "5.4.1"
   },
   "dependencies": {
     "@vercel/postgres": "^0.10.0",
     "graphql": "^16.9.0"
+  },
+  "peerDependencies": {
+    "ioredis": "^5.4.0"
+  },
+  "peerDependenciesMeta": {
+    "ioredis": {
+      "optional": true
+    }
   }
 }