Who is FerretDB?
FerretDB is an open source database compatibility layer that allows applications using the MongoDB wire protocol to run on top of PostgreSQL or other Structured Query Language (SQL) databases.
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- Open source MongoDB-compatible interface running on PostgreSQL and other backend databases (data management).
- Focus on protocol compatibility with the MongoDB wire protocol for application interoperability.
- Use of PostgreSQL as a primary backend engine for storage, indexing, and query execution.
- Targeted at users seeking a document-database-style Application Programming Interface (API) backed by relational database infrastructure.
- Emphasis on transparent integration with existing MongoDB client drivers and tools where supported.
More About FerretDB
FerretDB provides a MongoDB-compatible interface that maps application queries and commands expressed via the MongoDB wire protocol onto SQL operations executed by PostgreSQL or other supported backend databases (data management). This approach enables organizations that have standardized on relational infrastructure to deploy document-oriented workloads without running a separate proprietary document database engine. In enterprise environments, FerretDB is used as a compatibility layer, allowing existing MongoDB client libraries and tools to communicate with a backend built on PostgreSQL, which many organizations already operate for transactional and analytical workloads.
The core architecture of FerretDB sits between MongoDB drivers and the underlying database, translating BSON-based requests into SQL queries and schema constructs. It supports common MongoDB API elements such as collections, documents, and query operators, while persisting data in tables, indexes, and relational structures managed by PostgreSQL. This enables features like ACID transactions, durability, and operational characteristics that are part of PostgreSQL, while still presenting a document-oriented model at the application layer. For connectivity, FerretDB relies on the MongoDB wire protocol on the northbound side and standard PostgreSQL protocols on the southbound side.
From a solution-category perspective, FerretDB fits into database compatibility and data management tooling for organizations that want MongoDB-like semantics on top of relational platforms. It is deployed as an intermediate service, often containerized or orchestrated in Kubernetes or similar environments, and can integrate with monitoring, logging, and backup solutions already used for PostgreSQL. Because it is open source, enterprises can inspect and adapt the software to align with infrastructure, security, and compliance requirements, while keeping data stored in databases they control.
In comparison to running a separate document database, FerretDB focuses on reuse of PostgreSQL skills, tooling, and hosting platforms. This can simplify operations for teams with existing PostgreSQL expertise, as day-to-day administration such as replication, backup, scaling, and performance tuning can follow PostgreSQL practices. At the same time, application teams can use familiar MongoDB drivers in languages like Java, Python, JavaScript, and Go, reducing changes in application code. In a directory or marketplace taxonomy, FerretDB is categorized under database compatibility layers, document database interfaces, and PostgreSQL-based data management solutions.
Our description of FerretDB. Updated January 2026.
