> For the complete documentation index, see [llms.txt](https://docs.eiffel.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.eiffel.dev/features/transactional-outbox.md).

# Transactional outbox

- [PostgreSQL](https://docs.eiffel.dev/features/transactional-outbox/postgresql.md)
- [MongoDB (cluster only)](https://docs.eiffel.dev/features/transactional-outbox/mongodb-cluster-only.md)