Memory State Adapter

The Memory state adapter (ChatSDK::State::Memory) stores all state data in-process using Ruby hashes protected by a Mutex.

Configuration

No gem or external dependency is needed. Memory state is included in the core chat_sdk gem.

require "chat_sdk"

state = ChatSDK::State::Memory.new

bot = ChatSDK::Chat.new(
  user_name: "my-bot",
  adapters: { slack: slack },
  state: state
)

When to Use

Use Memory state when:

• Developing locally
• Running tests
• Deploying a single-process application where state loss on restart is acceptable

Limitations

• Not multi-process safe -- Each process has its own isolated state. Thread subscriptions, locks, and dedupe records are not shared.
• Not persistent -- All data is lost when the process exits.
• Memory usage grows -- Without Redis TTL eviction, expired keys are only cleaned up on access. In long-running processes, the in-memory store may grow.

Thread Safety

Memory state uses a Mutex to synchronize all reads and writes. Multiple Ruby threads within the same process can safely access the state concurrently.

Clearing State

state = ChatSDK::State::Memory.new
state.clear  # Removes all subscriptions, locks, and stored values

This is useful in tests to reset state between examples.

TTL Behavior

TTL-based expiration is supported but lazy. Keys are only evicted when accessed after their TTL has elapsed. This means:

state.set("key", "value", ttl: 5)
sleep(6)
state.get("key")  # => nil (expired and cleaned up on access)

For production use with predictable memory behavior, prefer the Redis State adapter.