Atlas

Atlas is an open-source tool for managing and migrating database schemas, developed by Ariga. Written in Go with over 6,600 stars as of 2026, Atlas introduces a declarative approach where developers describe the desired schema state in HCL files, and Atlas computes the diff to generate necessary SQL DDL statements. Key features include: schema inspection and introspection for MySQL, PostgreSQL, MariaDB, SQLite, SQL Server, ClickHouse, and MongoDB, declarative migrations (atlas schema apply with --dry-run preview), versioned migrations (generating up/down SQL files with history table tracking, linear and non-linear migration histories with merge conflict detection), migration linting (analyzing for destructive changes and backwards-incompatible modifications), CI/CD integration (atlas migrate diff for pull requests, GitHub Actions and GitLab CI templates), schema-as-code workflow (Git-based version control and code review), Terraform provider for managing database schemas alongside infrastructure, Atlas Cloud for managed migration execution with ER diagrams and diff visualization, and database-specific DDL generation. As of 2026, version 0.30+ supports MySQL 5.7-8.4, PostgreSQL 10-17, SQLite 3.35+, SQL Server, ClickHouse, and MongoDB.