Ecto is a toolkit for data mapping and language integrated query for Elixir.
Ecto solves the problem of mapping data from various sources into Elixir structs and querying that data using language-integrated syntax. It works by providing a declarative approach to defining schemas and composing queries, allowing developers to work with structured data whether backed by a database or not. The toolkit supports multiple database backends through pluggable adapters, including PostgreSQL, MySQL, MSSQL, SQLite3, and ClickHouse, as well as non-database sources like ETS.
Ecto suits projects built in Elixir that need to interact with relational databases or map external data into Elixir structures. Teams should choose it when they want a strongly-typed, composable approach to data access that integrates naturally with Elixir's pattern matching and functional paradigms. The project is particularly valuable for applications requiring complex queries and data transformations, as it provides language-integrated query capabilities rather than string-based SQL construction. Adoption requires adding both Ecto and a database-specific adapter as dependencies, with PostgreSQL, MySQL, and SQLite3 being the most commonly used options.
The project maintains multiple supported versions with a clear support policy, providing bug fixes for the latest branch and security patches for several prior versions. Integration testing is comprehensive, with a dedicated integration test suite that runs against actual database instances in containerized environments. The toolkit's API has stabilized, with the project now focused on delivering bug fixes and incremental improvements rather than major architectural changes.
