Reconstruct transaction and account history
Append transaction changes as ordered events, rebuild an account balance at a past sequence, and trace a result back to the events that produced it.
The transaction log your regulators expect
Immutable Transaction Log
Represent each debit, credit, transfer, fee, and correction as an append-only event. WAL CRC32 checks detect corrupted entries during recovery; storage and replication policy still determine durability.
Point-in-Time Balance Reconstruction
Replay events up to any timestamp to reconstruct exact account balances. Answer 'what was the balance at 3:47 PM on March 12th?' in milliseconds, not hours.
Evidence for Compliance Workflows
Immutable history and provenance can support MiFID II, SOX, and SOC 2 controls. Your system design, retention policy, access controls, and audit process still determine compliance.
Double-Entry Verification via Projections
Define projections that check double-entry invariants and emit an imbalance when credits and debits diverge. Your domain model supplies the accounting rules; AllSource supplies ordered inputs and replay.
Low-Latency Reconciliation Reads
Cross-reference transaction logs and flag discrepancies as new events arrive. The published 11.9us p99 Core indexed-read reference does not measure a complete reconciliation workflow.
Multi-Tenant Isolation for Client Accounts
Tenant IDs scope event streams, while role-based API permissions limit which client accounts a user or service can query.
Time-travel any account balance
Reconstruct the exact balance at any point in history
# What was account balance at market close on March 15th?
curl -s https://api.all-source.xyz/api/v1/events/query \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"entity_id": "acct-001-trading",
"as_of": "2026-03-15T16:00:00Z",
"event_type": "transaction.*"
}'
# {"events": [...], "count": 2341}
# Replay all 2,341 transactions to get exact balance: $1,247,892.43
# Compare with end-of-day balance from counterparty system
curl -s https://api.all-source.xyz/api/v1/projections/account-balance \
-H "Authorization: Bearer $API_KEY" \
-G -d "entity_id=acct-001-trading" \
-d "as_of=2026-03-15T16:00:00Z"
# {"projection": {"balance": 1247892.43, "currency": "USD",
# "last_tx": "2026-03-15T15:59:47Z", "tx_count": 2341}}
# Reconciliation complete — balances match to the centYour ledger of record
Immutable transactions, instant time-travel, and regulatory compliance built into the storage engine. Not bolted on after.