ai-instructions: Instructions file for GitHub Copilot

Spring Boot Redis Contract

Apply this contract only when a Spring Boot application integrates with Redis through Spring Data Redis. It governs the client application, not Redis server provisioning.

Pom owns dependency comments and ordering. Configuration owns profiles and secrets. Architecture owns feature packages, repositories, services, and constructor injection. Controller owns *RestController naming and boundaries. Logging and i18n own log/error keys. JDBC/database contracts own the primary store when Redis is only a cache. Spring ApplicationEvent is out of scope (events contract).

Prefer one primary role per module: datastore, cache layer, or pub/sub.

Dependency

• Add org.springframework.boot:spring-boot-starter-data-redis (Lettuce is the default client from the starter).
• When using Spring Cache annotations with Redis as the store, also add org.springframework.boot:spring-boot-starter-cache.
• Do not add Jedis or a raw Lettuce dependency unless there is an approved need outside the Boot starter.

Connection

• Configure spring.data.redis.host and port from environment variables (for example REDIS_HOST / REDIS_PORT with localhost / 6379 defaults).
• Do not set spring.data.redis.password unless the Redis instance requires AUTH.

RedisTemplate (datastore and pub/sub)

• Register a RedisTemplate<String, String> bean with StringRedisSerializer for keys and values (and hash key/value serializers when using hashes).
• Encode/decode domain JSON with Jackson in the feature layer (repository, publisher, or listener). Do not switch the template to a Java-object value serializer for those roles.
• When the module needs an ObjectMapper bean and Boot does not expose one, register a module-aware mapper next to the template.

Datastore

• Use a feature repository with HashOperations.
• Prefer stable Redis key / hash names owned by the feature.
• Fail clearly on serialize/deserialize errors; do not return corrupt payloads.