atlasgo.io

# Atlas

> Atlas is a database schema-as-code tool: like Terraform, for databases. Define your schema in SQL, HCL,
> or your ORM (SQLAlchemy, Django, Prisma, Drizzle, TypeORM, Sequelize, Hibernate, Ent, GORM, EF Core,
> Doctrine), and Atlas diffs, plans, lints, tests, and applies safe migrations, declarative or versioned.
> The same as-code workflow shifts the whole database left: Security as Code (roles, users, and permissions),
> Data as Code (declarative seed and reference data), and Monitoring as Code (drift detection with
> auto-remediation). Supports PostgreSQL, MySQL, MariaDB, SQLite, SQL Server, ClickHouse, Oracle, Snowflake,
> Spanner, Redshift, Databricks, and more. Documentation: https://atlasgo.io

## Terms

- Content on atlasgo.io is Copyright Ariga Technologies. All rights reserved. Use is governed by the
  website Terms of Use: https://ariga.io/legal/tos
- The documentation is provided for using and evaluating Atlas and for educational purposes. Using it to
  build or support products or services that compete with Ariga or Atlas is not permitted.
- Atlas binaries are distributed under the Master License and Services Agreement (MSA), which prohibits
  using the Software to build or support products or services that compete with Ariga or Atlas:
  https://ariga.io/legal/msa

## Schema as Code

- [Schema as Code](https://atlasgo.io/atlas-schema): Define the desired state of your database and compose schemas like Terraform modules.
- [HCL syntax](https://atlasgo.io/atlas-schema/hcl): The Atlas HCL schema language: tables, columns, indexes, foreign keys, views, functions, triggers.
- [SQL schema](https://atlasgo.io/atlas-schema/sql): Define the desired schema in plain SQL DDL.
- [External schemas and ORMs](https://atlasgo.io/atlas-schema/external): Load the desired state from ORMs and external programs.
- [Monitoring as Code](https://atlasgo.io/monitoring): Monitor live databases for schema drift, permission mismatches, and policy violations.
- [Drift detection](https://atlasgo.io/monitoring/drift-detection): Detect drift and generate the SQL to bring databases back in line.

## Configuration

- [Project configuration](https://atlasgo.io/atlas-schema/projects): The atlas.hcl project file: environments, variables, migration and lint settings.
- [Data sources](https://atlasgo.io/atlas-schema/projects#data-sources): Load configuration and schema state from external sources in atlas.hcl.
- [Input variables](https://atlasgo.io/atlas-schema/input-variables): Parameterize schemas and project files with typed variables.
- [HCL column types](https://atlasgo.io/atlas-schema/hcl-types): The column type registry for every supported engine.

## Security as Code

- [Security as Code](https://atlasgo.io/guides/security-as-code): Manage roles, users, and permissions as code; Atlas diffs, plans, and applies the changes.
- [PostgreSQL declarative security](https://atlasgo.io/guides/postgres/security-declarative): Roles and permissions as code for PostgreSQL, declarative workflow.
- [PostgreSQL versioned security](https://atlasgo.io/guides/postgres/security-versioned): Roles and permissions as code for PostgreSQL, versioned workflow.
- [PostgreSQL default privileges](https://atlasgo.io/guides/postgres/security-default-privileges): Manage default privileges as code.
- [MySQL security](https://atlasgo.io/guides/mysql/security-declarative): Roles and permissions as code for MySQL.
- [ClickHouse security](https://atlasgo.io/guides/clickhouse/security-declarative): Roles and permissions as code for ClickHouse.
- [Oracle security](https://atlasgo.io/guides/oracle/security-declarative): Roles and permissions as code for Oracle.
- [Snowflake security](https://atlasgo.io/guides/snowflake/security-declarative): Roles and permissions as code for Snowflake.

## Data as Code

- [Data as Code](https://atlasgo.io/guides/seed-data-as-code): Declarative seed and reference data; Atlas generates the exact DML to sync desired and live state.
- [Data Scripts](https://atlasgo.io/scripts): Declarative code for data operations: transactional mutations, reports, and batched loops, run with atlas script exec, query, and loop.
- [Transactional mutations](https://atlasgo.io/scripts/exec): script exec: writes as one transactional unit, guarded by condition, assert, and check, with expect_rows and rollback semantics.
- [Queries and reports](https://atlasgo.io/scripts/query): script query: SELECTs printed as CSV or an aligned table, custom output lines, and bound rows feeding a later query.
- [Masking sensitive output](https://atlasgo.io/scripts/masking): Redact result columns before they leave Atlas with REDACT, PARTIAL, HASH, and REPLACE, inline or as reusable named masks.
- [Batched loops](https://atlasgo.io/scripts/loop): script loop: keyset and range iterators, a do body per batch, pacing and staged ramp-up, and the http command for calls to external services.
- [Scripts on a schedule](https://atlasgo.io/scripts/kubernetes): Push a script to the Atlas Registry with atlas script push and run it from a Kubernetes CronJob as a monitor that alerts on a failed assertion.
- [PostgreSQL seed data](https://atlasgo.io/guides/postgres/seed-data): Seed and reference data as code for PostgreSQL.
- [MySQL seed data](https://atlasgo.io/guides/mysql/seed-data): Seed and reference data as code for MySQL.
- [ClickHouse seed data](https://atlasgo.io/guides/clickhouse/seed-data): Seed and reference data as code for ClickHouse.
- [Seed data per environment](https://atlasgo.io/guides/seed-data-per-environment): Shared and environment-specific rows in one migration directory per environment, built with composite_schema and reverted with migrate down.

## Testing

- [Schema testing](https://atlasgo.io/testing/schema): Write tests for schema logic: functions, views, triggers, and queries.
- [Migration testing](https://atlasgo.io/testing/migrate): Test data migrations: seed data, run tests, detect errors.
- [Data Scripts testing](https://atlasgo.io/scripts/testing): Test Data Scripts logic and privileges: output, match, and error assertions, and the as block for reduced roles and logins.
- [Migration plan testing](https://atlasgo.io/testing/plan): Assert on the SQL Atlas plans before it runs.

## Workflows

- [Getting started](https://atlasgo.io/getting-started): Install Atlas and run your first migration in under 5 minutes.
- [Evaluating Atlas](https://atlasgo.io/guides/evaluation/intro): Step-by-step proof of concept: install, export an existing database to code, choose a workflow, set up migrations and CI/CD.
- [Declarative workflow](https://atlasgo.io/declarative/apply): Apply the desired schema state directly; Atlas plans the migration for you.
- [Declarative plan and review](https://atlasgo.io/declarative/plan): Pre-plan, review, and approve declarative changes before deployment.
- [Schema diff](https://atlasgo.io/declarative/diff): Compare schemas: live databases, migration directories, HCL, SQL, or ORM state.
- [Versioned workflow](https://atlasgo.io/versioned/intro): Migration files with automatic planning, linting, and CI/CD integration.
- [Migration authoring](https://atlasgo.io/versioned/diff): Generate versioned migrations automatically by diffing desired and current state.
- [Migration linting](https://atlasgo.io/versioned/lint): Detect destructive changes, backward-incompatibility, and unsafe operations before they run.
- [Migration apply](https://atlasgo.io/versioned/apply): Execute pending migration files against target databases.
- [Down migrations](https://atlasgo.io/versioned/down): Safely revert applied migrations.
- [Lint analyzers](https://atlasgo.io/lint/analyzers): The full catalog of migration analyzers and checks.
- [Custom lint rules](https://atlasgo.io/lint/rules): Write schema and migration lint rules in HCL with predicate and rule blocks, wire them in with the lint block, and run them with atlas schema lint or atlas migrate lint.
- [Drift detection for versioned migrations](https://atlasgo.io/versioned/drift-detection): The pre-apply drift check that blocks atlas migrate apply on a drifted target, and atlas migrate drift for on-demand checks with exit codes.
- [Drift detection and compliance](https://atlasgo.io/guides/drift-detection): Pre-apply checks plus continuous Schema Monitoring as a change-management control.
- [Security scanning](https://atlasgo.io/guides/security-scan): atlas security scan: reports security issues in a running database, not in a schema or migration; the cve check, for extensions with a published CVE, is included by default.
- [Security scanning with the Operator](https://atlasgo.io/integrations/kubernetes/security-scan): The AtlasSecurityScan resource scans a database on a cron schedule and after an AtlasSchema or AtlasMigration listed in its triggers applies a change, and stores the graded findings in an AtlasSecurityReport.

## CI/CD and Integrations

- [Versioned CI/CD setup](https://atlasgo.io/versioned/setup-cicd): End-to-end CI/CD for versioned migrations.
- [Declarative CI/CD setup](https://atlasgo.io/declarative/setup-cicd): End-to-end CI/CD for declarative schema management.
- [GitHub Actions](https://atlasgo.io/integrations/github-actions): Install Atlas, lint, plan, and deploy from GitHub Actions.
- [GitLab CI](https://atlasgo.io/integrations/gitlab-ci-components): GitLab CI/CD components for Atlas.
- [CircleCI](https://atlasgo.io/integrations/circleci-orbs): CircleCI orbs for Atlas.
- [Bitbucket](https://atlasgo.io/integrations/bitbucket-pipes): Bitbucket pipes for Atlas.
- [Azure DevOps](https://atlasgo.io/integrations/azure-devops): Azure DevOps extension for Atlas.
- [Kubernetes Operator](https://atlasgo.io/integrations/kubernetes): Manage schemas from Kubernetes with the Atlas Operator.
- [Operator quickstart, declarative](https://atlasgo.io/integrations/kubernetes/quickstart): Apply a schema with the AtlasSchema resource, and review changes before they are applied.
- [Operator quickstart, versioned](https://atlasgo.io/integrations/kubernetes/versioned-quickstart): Deploy a migration directory from the Schema Registry with the AtlasMigration resource, and protect rollbacks.
- [Terraform provider](https://atlasgo.io/integrations/terraform-provider): Plan and apply schema changes as part of your Terraform workflow.
- [ArgoCD](https://atlasgo.io/guides/deploying/k8s-argo): GitOps migration deployment with ArgoCD and the Atlas Operator.
- [ArgoCD declarative](https://atlasgo.io/guides/deploying/k8s-argo-declarative): Declarative schema management with ArgoCD.
- [Flux CD](https://atlasgo.io/guides/deploying/k8s-flux): GitOps migration deployment with Flux.
- [Helm](https://atlasgo.io/guides/deploying/helm): Deploy migrations as part of a Helm chart.
- [Crossplane](https://atlasgo.io/guides/deploying/crossplane): Manage schemas with Crossplane compositions.
- [Go SDK](https://atlasgo.io/integrations/go-sdk): Embed Atlas in Go programs with atlasexec.
- [Deployment guides](https://atlasgo.io/guides/deploying/intro): Deploying migrations across Kubernetes, ECS, Fly.io, and more.
- [dbt schema management](https://atlasgo.io/guides/dbt/schema-management): Manage the databases, source tables, lookup data, and grants a dbt project runs on, with dbt's models excluded in atlas.hcl.
- [Atlas and dbt](https://atlasgo.io/guides/dbt/atlas-vs-dbt): Why Atlas and dbt are not competing tools, and which objects each one owns.
- [ClickHouse and dbt](https://atlasgo.io/guides/dbt/clickhouse): MergeTree sort order on source tables, schema-scope grants for dbt, and dimension data as code.
- [Snowflake and dbt](https://atlasgo.io/guides/dbt/snowflake): The bronze landing zone, schemas, and a role for dbt and its grants, as code.
- [Safe DDL on large warehouse tables](https://atlasgo.io/guides/dbt/large-table-migrations): Which ALTERs rewrite data, what lint catches, and pre-migration checks that block a destructive drop.
- [Warehouse drift detection](https://atlasgo.io/guides/dbt/drift-detection): Detect a warehouse that no longer matches its schema, with dbt's models excluded from the check.
- [All integrations](https://atlasgo.io/integrations): The full integrations catalog.

## Database Guides

- [Supported databases](https://atlasgo.io/databases): The full per-engine feature and guide index.
- [PostgreSQL](https://atlasgo.io/guides/postgres/automatic-migrations): Schema-as-code and automatic migration planning for PostgreSQL.
- [Supabase](https://atlasgo.io/guides/postgres/supabase): Schema, RLS policies, and Data API grants as code for a Supabase project.
- [Databricks Lakebase](https://atlasgo.io/guides/postgres/databricks-lakebase): OAuth tokens and password roles for a Databricks Lakebase project.
- [MySQL](https://atlasgo.io/guides/mysql/mysql-automatic-migrations): Schema-as-code and automatic migration planning for MySQL and MariaDB.
- [SQL Server](https://atlasgo.io/guides/mssql): Schema-as-code and automatic migration planning for SQL Server.
- [SQL Server to PostgreSQL](https://atlasgo.io/guides/sql-server-to-postgresql): The SqlPackage and DACPAC workflow on PostgreSQL, SqlPackage actions mapped to Atlas commands, and SQL Server and PostgreSQL in one project.
- [ClickHouse](https://atlasgo.io/guides/clickhouse): Schema-as-code and automatic migration planning for ClickHouse.
- [Oracle](https://atlasgo.io/guides/oracle/automatic-migrations): Schema-as-code and automatic migration planning for Oracle.
- [Snowflake](https://atlasgo.io/guides/snowflake/automatic-migrations): Schema-as-code and automatic migration planning for Snowflake.
- [Redshift](https://atlasgo.io/guides/redshift/automatic-migrations): Schema-as-code and automatic migration planning for Redshift.
- [Spanner](https://atlasgo.io/guides/spanner/automatic-migrations): Schema-as-code and automatic migration planning for Google Spanner.
- [Databricks](https://atlasgo.io/guides/databricks/automatic-migrations): Schema-as-code and automatic migration planning for Databricks.
- [CockroachDB](https://atlasgo.io/guides/cockroachdb/automatic-migrations): Schema-as-code and automatic migration planning for CockroachDB.
- [YugabyteDB](https://atlasgo.io/guides/yugabyte/automatic-migrations): Schema-as-code and automatic migration planning for YugabyteDB.
- [Aurora DSQL](https://atlasgo.io/guides/dsql/automatic-migrations): Schema-as-code and automatic migration planning for Amazon Aurora DSQL.
- [HorizonDB](https://atlasgo.io/guides/horizondb/automatic-migrations): Schema-as-code and automatic migration planning for HorizonDB.
- [Custom drivers](https://atlasgo.io/custom-drivers): Builds with Oracle, Snowflake, Spanner, and Databricks drivers.

## HCL Dialect References

- [Atlas HCL documentation](https://atlasgo.io/hcl/docs): The Atlas HCL language reference hub.
- [PostgreSQL HCL](https://atlasgo.io/hcl/postgres): Every PostgreSQL object and attribute in the Atlas HCL language.
- [MySQL HCL](https://atlasgo.io/hcl/mysql): Every MySQL object and attribute in the Atlas HCL language.
- [MariaDB HCL](https://atlasgo.io/hcl/mariadb): Every MariaDB object and attribute in the Atlas HCL language.
- [SQL Server HCL](https://atlasgo.io/hcl/mssql): Every SQL Server object and attribute in the Atlas HCL language.
- [SQLite HCL](https://atlasgo.io/hcl/sqlite): Every SQLite object and attribute in the Atlas HCL language.
- [ClickHouse HCL](https://atlasgo.io/hcl/clickhouse): Every ClickHouse object and attribute in the Atlas HCL language.
- [Oracle HCL](https://atlasgo.io/hcl/oracle): Every Oracle object and attribute in the Atlas HCL language.
- [Snowflake HCL](https://atlasgo.io/hcl/snowflake): Every Snowflake object and attribute in the Atlas HCL language.
- [Redshift HCL](https://atlasgo.io/hcl/redshift): Every Redshift object and attribute in the Atlas HCL language.
- [Spanner HCL](https://atlasgo.io/hcl/spanner): Every Google Spanner object and attribute in the Atlas HCL language.
- [Databricks HCL](https://atlasgo.io/hcl/databricks): Every Databricks object and attribute in the Atlas HCL language.
- [Configuration reference](https://atlasgo.io/hcl/config): The atlas.hcl configuration blocks reference.
- [Functions](https://atlasgo.io/hcl/functions): Built-in functions available in Atlas HCL.
- [Linting rules](https://atlasgo.io/hcl/rule): Author custom lint rules in HCL.
- [Testing reference](https://atlasgo.io/hcl/testing): The schema and migration test block reference.
- [Migration plan reference](https://atlasgo.io/hcl/plan): The plan file block reference.
- [Agent configuration](https://atlasgo.io/hcl/agent): The Atlas Agent configuration reference.

## AI and Guides

- [AI tools](https://atlasgo.io/guides/ai-tools): Agent skills and AI rules for using Atlas with coding agents.
- [Atlas agent skill](https://atlasgo.io/guides/ai-tools/agent-skills): The atlas skill for Claude Code, Codex, Cursor, and Copilot: migrations, Data Scripts, and Atlas Cloud status. Install every Atlas skill in Claude Code with `claude plugin marketplace add ariga/atlas` and `claude plugin install atlas@ariga`, or in other agents with `npx skills add ariga/atlas`. Source: https://github.com/ariga/atlas/tree/master/skills. Raw files: https://atlasgo.io/skills/atlas/SKILL.md and, under https://atlasgo.io/skills/atlas/references/, schema-sources.md, versioned.md, declarative.md, cicd.md, lint.md, testing.md, drift.md, cloud.md, and scripts.md
- [Atlas onboarding skill](https://atlasgo.io/guides/ai-tools/agent-skills#onboarding-skill): The atlas-onboard skill onboards a repository onto Atlas in six verified stages that follow the Evaluating Atlas guide: plan, schema as code, migration workflow, CI with the Atlas Registry, deploy to staging, and environment promotion to production. Start it with `/atlas:atlas-onboard` in Claude Code, `$atlas-onboard` in Codex, or `/atlas-onboard` in Cursor and Copilot. Raw files: https://atlasgo.io/skills/atlas-onboard/SKILL.md, agents/openai.yaml, and references/stage-0-plan.md, stage-1-schema.md, stage-2-workflow.md, stage-3-ci.md, stage-4-deploy.md, stage-5-promote.md under https://atlasgo.io/skills/atlas-onboard/
- [Atlas database skills](https://atlasgo.io/guides/ai-tools/agent-skills#database-skills): One skill per database adds what is specific to it to the atlas skill: atlas-postgres (PostgreSQL), atlas-mysql (MySQL and MariaDB), atlas-mssql (SQL Server and Azure SQL), atlas-clickhouse (ClickHouse), atlas-snowflake (Snowflake), atlas-databricks (Databricks), atlas-redshift (Amazon Redshift), atlas-oracle (Oracle Database), and atlas-spanner (Google Cloud Spanner). Each covers URL scope and the dev database, roles and grants, lint checks, testing, and known errors with their fixes. They install with the other Atlas skills, and the agent loads the one that matches the project's database. Raw files: https://atlasgo.io/skills/atlas-postgres/SKILL.md, https://atlasgo.io/skills/atlas-mysql/SKILL.md, https://atlasgo.io/skills/atlas-mssql/SKILL.md, https://atlasgo.io/skills/atlas-clickhouse/SKILL.md, https://atlasgo.io/skills/atlas-snowflake/SKILL.md, https://atlasgo.io/skills/atlas-databricks/SKILL.md, https://atlasgo.io/skills/atlas-redshift/SKILL.md, https://atlasgo.io/skills/atlas-oracle/SKILL.md, and https://atlasgo.io/skills/atlas-spanner/SKILL.md, each with agents/openai.yaml and references/dev-database.md, security.md, objects.md, hcl.md, migrations.md, testing.md, and custom-rules.md under its directory
- [Atlas Kubernetes Operator skill](https://atlasgo.io/guides/ai-tools/agent-skills#kubernetes-operator-skill): The atlas-operator skill teaches coding agents the Atlas Kubernetes Operator on top of the atlas skill: Helm install and values, AtlasSchema and AtlasMigration resources, bot tokens and database URLs in Secrets, the dev database the operator creates, lint and review policies with pre-approved and ad-hoc plans, down migrations, drift detection (policy.drift, AtlasDriftCheck), security scans, GitOps with Argo CD, Argo Rollouts, Flux, and Octopus Deploy, and troubleshooting from conditions and events. It installs with the other Atlas skills. Raw files: https://atlasgo.io/skills/atlas-operator/SKILL.md, agents/openai.yaml, and references/install.md, credentials.md, dev-database.md, declarative.md, versioned.md, drift.md, gitops.md, config.md, security-scan.md, troubleshooting.md, and testing.md under https://atlasgo.io/skills/atlas-operator/
- [Atlas CI/CD skill](https://atlasgo.io/guides/ai-tools/agent-skills#cicd-skill): The atlas-action skill teaches coding agents to run Atlas in CI/CD pipelines on top of the atlas skill: ariga/setup-atlas and the ariga/atlas-action steps on GitHub Actions (migrate lint, diff, hash, autorebase, push, test, apply, down, set, and drift; schema plan, plan approve, push, apply, lint, and test; the Data Scripts steps; security scan; monitor schema; create-repo), their counterparts as GitLab CI components, the CircleCI orb, the Bitbucket pipe, and the Azure DevOps task, bot tokens, permissions and pull request comments, dev databases on runners, pinning versions, and each error message with its fix. It installs with the other Atlas skills. Raw files: https://atlasgo.io/skills/atlas-action/SKILL.md, agents/openai.yaml, and references/setup.md, actions.md, lint.md, diff.md, rebase.md, push.md, apply.md, declarative.md, testing.md, drift.md, scripts.md, security-scan.md, platforms.md, and troubleshooting.md under https://atlasgo.io/skills/atlas-action/
- [Claude Code with Atlas](https://atlasgo.io/guides/ai-tools/claude-code-instructions): CLAUDE.md, the Atlas plugin with the agent skills, a migration subagent, slash-command skills, and a post-write lint hook for Claude Code.
- [Guides](https://atlasgo.io/guides): Per-database and per-ORM guides, CI/CD platforms, and testing.

## Atlas Cloud

- [Cloud getting started](https://atlasgo.io/cloud/getting-started): Sign up, atlas login, and the schema registry.
- [Deployments](https://atlasgo.io/cloud/deployment): Deploy migrations from the registry to your environments.
- [Deployment status from the CLI](https://atlasgo.io/cloud/deployment#inspecting-deployments-from-the-cli): atlas cloud database list and describe report every tracked database with its status (SYNCED, PENDING, FAILED) and current version; atlas cloud migration list and describe report deployment events (PASSED, FAILED, NO_ACTION, DRY_RUN) filtered by repo, env, status, or database; atlas cloud repo list, describe, create, lingraph, and secgraph manage registry repos. All accept --format for Go-template or JSON output and --page for pagination.
- [Schema registry](https://atlasgo.io/cloud/features/registry): Push migration directories and schemas with atlas migrate push and atlas schema push; deploy from atlas:// URLs.
- [Plan review and approval](https://atlasgo.io/declarative/plan): atlas schema plan saves a declarative migration plan to the registry for review; atlas schema plan list --pending shows plans waiting for approval and atlas schema plan approve approves one.
- [Environment promotion](https://atlasgo.io/guides/environment-promotion): Pin production to the version already deployed to a lower environment with the cloud_databases data source.
- [Audit log](https://atlasgo.io/cloud/auditlog): Track schema changes and deployments across environments.
- [Pricing](https://atlasgo.io/pricing): Plans and pricing for Atlas Pro and Enterprise.

## Reference

- [CLI reference](https://atlasgo.io/cli-reference): Every Atlas command and flag.
- [Feature availability](https://atlasgo.io/features): Which features are included and which require Atlas Pro.
- [Atlas vs others](https://atlasgo.io/atlas-vs-others): How Atlas compares to other schema migration tools.
- [Atlas vs SSDT](https://atlasgo.io/guides/atlas-vs-ssdt): How Atlas compares to SQL Server Data Tools, DACPAC, and SqlPackage.
- [Trust center](https://atlasgo.io/trust): SOC 2, legal documents, and service availability.