Atmos is an open-source framework by Cloud Posse for managing Terraform at scale using stacks, components, and inheritance to organize complex multi-account AWS environments.
Atmos provides a structured framework for organizing Terraform configurations at scale. It introduces the concepts of stacks (environment configurations) and components (reusable Terraform root modules) to manage complex infrastructure across multiple accounts and regions.
Configuration is defined in YAML stack files that support deep merging, imports, and inheritance—allowing teams to define base configurations once and override them per environment.
As infrastructure grows beyond a handful of Terraform workspaces, managing variables, backends, and dependencies becomes increasingly complex. Atmos solves this by providing a consistent structure that scales from 5 to 500+ Terraform components.
Teams using Atmos report faster onboarding, fewer configuration errors, and easier compliance with organizational standards.
Atmos wraps standard Terraform commands, adding stack awareness and configuration management. Every atmos terraform plan or atmos terraform apply call resolves the full configuration for a component in a stack, then executes Terraform with the correct variables and backend configuration.
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