# XTDB — Bitemporal Database with Immutable History > XTDB is an open-source bitemporal database that records both valid time and transaction time for every fact. Query your data as it was at any point in time, or as it was known at any point — with full SQL support. ## Install Copy the content below into your project: --- Source: https://tokrepo.com/en/workflows/xtdb-bitemporal-database-immutable-history-0b2dc663 Author: