BACKEND_INDEXER_FOUNDATION.md

Backend Indexer Foundation

Purpose

Shift backend responsibilities toward read models, analytics, and event projection from Soroban events.

Added Foundation

• IndexerModule
• replay-safe IngestedEventEntity with unique (network, txHash, eventIndex)
• SessionProjectionEntity for read API projections
• EventProcessorService for idempotent processing
• ProjectionService for projection updates
• IndexerController ingestion endpoint scaffold

Extending the Indexer

To add new projections and read endpoints, follow the comprehensive guide: Backend Read-Model Extension Guide

This guide provides a standardized pattern for:

1. Creating projection entities with proper indexing
2. Implementing idempotent event processing
3. Adding read APIs with proper DTOs
4. Writing comprehensive tests
5. Maintaining replay safety and schema versioning

Next Steps

• Replace manual ingest endpoint with Soroban RPC poller worker
• Add durable cursor/checkpoint table
• Expand projections for leaderboard/day stats