Fauna was a serverless, distributed database run as a cloud service by Fauna, Inc. Serverless means that customers never chose servers, clusters or memory sizes: the service provisioned and scaled itself. The service ended on 30 May 2025. This description comes from the Internet Archive copy of fauna.com from 22 May 2025; the fauna.com address now leads to an unrelated robotics company.
Fauna used a document-relational model: data was stored as JSON documents, which could be joined and queried relationally with FQL, a TypeScript-inspired query language, with ACID transactions and indexes. Applications connected over an HTTPS API with token-based authentication instead of keeping database connections open. Reads and writes were replicated automatically across three regions, and a transaction engine inspired by the Calvin research design gave strict serializability, the strongest level of consistency. Access rules could be attribute-based or role-based, and child databases kept tenants apart.
In March 2025 Fauna announced that it would end the paid service and release an open-source version of its core database technology.