Adapter System

Amber 2.0 routes session storage and pub/sub messaging through adapter interfaces. In-memory adapters are built in; an application can register a separate implementation when it needs an external store or message broker.

Why Adapters?

In Amber 1.x, Redis was required for sessions and WebSocket messaging. This created issues:

• Required Redis installation for development
• External dependency even for simple apps
• No flexibility for other backends

Amber 2.0 solves this with:

• Memory-based adapters work immediately
• No external dependencies required
• Implement custom adapters for any backend
• Tests can use the in-memory implementations without an external service

Built-in Adapters

Memory Adapters (Default)

File: config/environments/development.yml — edit the existing session: and pubsub: keys. Apply the same shape deliberately to test.yml or production.yml; environment files do not inherit from one another.

session:
  key: "amber.session"
  store: "signed_cookie"
  adapter: "memory"
  expires: 3600

pubsub:
  adapter: "memory"

Memory adapters are perfect for:

• Development environments
• Testing
• Single-server deployments
• Simple applications

Cookie Sessions

For stateless session storage:

File: one file under config/environments/, such as config/environments/production.yml — replace that environment's existing session: section.

session:
  key: "amber.session"
  store: "signed_cookie"
  expires: 3600

Configuration

Session Configuration

File: config/environments/production.yml — replace the existing session: section after registering the custom database adapter.

session:
  key: "myapp.session"
  adapter: "database"  # Your custom adapter
  expires: 86400       # 24 hours

PubSub Configuration

File: the applicable file under config/environments/ — edit the existing pubsub: section.

pubsub:
  adapter: "memory"  # Or custom adapter name

Custom Adapters

Implement custom adapters for your specific needs:

• Database sessions (PostgreSQL, MySQL)
• Redis (via community shard)
• Cloud storage (AWS DynamoDB)
• Message queues (RabbitMQ, Kafka)

See Session Adapters and PubSub Adapters for implementation guides.

Migration from Redis

If you used Redis in Amber 1.x, see the Migration Guide for step-by-step migration instructions.