Event Processing

Event processors turn chain-native records into application facts. Correctness depends on decoding, ordering, deduplication, and finality state.

Source	Decode using	Stable identity
EVM logs	Contract ABI, topic0 event signature, indexed topics, data bytes	chain id, block hash, transaction hash, log index
Sui Move events	Move type plus BCS-decoded event payload where applicable	checkpoint, transaction digest, event sequence
Aptos events	Event type, account/module context, REST or indexer payload	ledger version, transaction hash, event index
Solana logs/account changes	Program id, instruction data, account keys, log line conventions	slot, signature, instruction/log index when available

Ordering should be explicit. Do not rely on database insertion order or WebSocket arrival order. Persist the chain's ordering keys and sort by them when replaying.

CREATE UNIQUE INDEX events_source_uidx ON events (
  chain,
  source_height,
  transaction_id,
  event_index
);

:::warning Decode failures are data quality events Do not silently drop undecodable events. Store the raw payload, decoder version, error, and source identity so the indexer can replay after an ABI, Move type, or parser update. :::

Downstream systems should consume normalized events only after the indexer assigns a dedupe key and finality status.