Adapters

LoopStore interface

All persistence adapters must implement:

1getInstance(aggregateId: AggregateId): Promise<LoopInstance | null>
2saveInstance(instance: LoopInstance): Promise<void>
3getTransitionHistory(aggregateId: AggregateId): Promise<TransitionRecord[]>
4saveTransitionRecord(record: TransitionRecord): Promise<void>
5listOpenInstances(loopId: LoopId): Promise<LoopInstance[]>

@loop-engine/adapter-memory

1import { memoryStore } from '@loop-engine/adapter-memory'
2const store = memoryStore()

Use for tests, local development, browser demos.
Data resets on process restart.

@loop-engine/adapter-postgres

1import { postgresStore, createSchema, createPool, runMigrations } from '@loop-engine/adapter-postgres'
2 
3const pool = createPool({ connectionString: process.env.DATABASE_URL })
4await runMigrations(pool)
5const store = postgresStore(pool)

Schema creates:

• loop_instances
  • aggregate_id, loop_id, current_state, status, started_at, updated_at, completed_at, correlation_id, metadata
• loop_transitions
  • id, loop_id, aggregate_id, transition_id, from_state, to_state, actor, evidence, occurred_at, duration_ms
• schema_migrations
  • migration-tracking table managed by runMigrations

Additional exports: createSchema(pool) (legacy DDL helper; prefer runMigrations for incremental upgrades), plus Migration, MigrationRunResult, PoolOptions, PostgresStore types and error classification utilities.

Peer dependency: pg@^8.0.0.

Event bus adapters

@loop-engine/adapter-kafka

• Provides kafkaEventBus(...)
• Use for streaming and service-to-service fanout
• Peer dependency: kafkajs@^2.0.0

@loop-engine/adapter-http

• Provides httpEventBus(...)
• Use for webhooks and low-friction integrations
• subscribe() is intentionally unsupported (emit-only adapter)

Build a custom adapter

Implement LoopStore exactly and pass it to:

1createLoopSystem({ loops, store: myStore })