# Multi-Cloud

Atmos was designed from the ground up to be cloud agnostic. It works with any cloud provider that Terraform supports. Cloud-specific integrations for authentication and stores are community supported.

Atmos is a framework that helps you orchestrate Terraform — whatever you can do in Terraform, you can do with Atmos. Teams use it across a diverse set of environments, from AWS to Azure to GCP, as well as managing other platforms like Cloudflare, DigitalOcean, GitHub, Hetzner, Akamai, Artifactory, Vercel, and the list goes on.

Atmos itself is not aware of your Terraform components or their providers. Stacks, components, inheritance, vendoring, workflows, and the terminal UI are all completely cloud-agnostic. The only cloud-specific features are [authentication](/cli/configuration/auth) and [stores](/cli/configuration/stores), which have dedicated integrations for each provider. For simplification, many of our examples reference AWS since it is the most widely adopted cloud among our community, but the concepts apply regardless of which cloud you use.

## Design Patterns

Atmos provides design patterns for organizing your stacks across clouds and application repositories.

- **[Multi-Cloud Configuration](/design-patterns/stack-organization/multi-cloud-configuration)** — Organize your stacks so the directory layout mirrors how your cloud provider organizes its resources. Uses cloud-native terminology in folder names (AWS accounts, Azure subscriptions, GCP projects) so engineers immediately understand the layout. Includes a cloud organizational concept mapping table for translating between providers.

- **[Application SDLC Environments](/design-patterns/stack-organization/application-sdlc)** — A minimal flat structure for application repositories that co-locate infrastructure alongside application code. One file per SDLC environment (`dev.yaml`, `staging.yaml`, `prod.yaml`) with support for ephemeral PR preview environments. Ideal for teams that want to get up and running quickly without deep organizational hierarchy.

## Cloud Integrations

To explore how multi-cloud integrations are configured, here are some examples for each provider.

### AWS

### Authentication

Atmos supports multiple AWS authentication flows including SSO, SAML, and GitHub OIDC.

**File:** `atmos.yaml`

```yaml
auth:
  providers:
    company-sso:
      kind: aws/iam-identity-center
      region: us-east-1
      start_url: https://company.awsapps.com/start
      auto_provision_identities: true

  identities:
    dev-admin:
      kind: aws/permission-set
      default: true
      via:
        provider: company-sso
      principal:
        name: AdminAccess
        account:
          name: development
```

**Providers:** `aws/iam-identity-center`, `aws/saml`, `github/oidc`
**Identities:** `aws/permission-set`, `aws/assume-role`, `aws/assume-root`, `aws/user`

### Stores

- **AWS SSM Parameter Store:** `aws-ssm-parameter-store`

### Terraform Backend

- **S3 + DynamoDB** — Remote state with locking

**Learn more:** [Auth Providers](/cli/configuration/auth/providers) · [Identities](/cli/configuration/auth/identities) · [Stores](/cli/configuration/stores)

### Azure

### Authentication

Atmos supports Azure authentication for interactive and CI/CD workflows.

**File:** `atmos.yaml`

```yaml
auth:
  providers:
    azure-interactive:
      kind: azure/device-code
      spec:
        tenant_id: "12345678-1234-1234-1234-123456789012"
        subscription_id: "87654321-4321-4321-4321-210987654321"

  identities:
    dev-subscription:
      kind: azure/subscription
      via:
        provider: azure-interactive
      principal:
        subscription_id: "87654321-4321-4321-4321-210987654321"
```

**Providers:** `azure/device-code`, `azure/oidc`, `azure/cli`
**Identities:** `azure/subscription`

### Stores

- **Azure Key Vault:** `azure-key-vault`

### Terraform Backend

- **Azure Blob Storage** — Remote state with native locking

**Learn more:** [Auth Providers](/cli/configuration/auth/providers) · [Azure Tutorial](/tutorials/azure-authentication) · [Stores](/cli/configuration/stores)

### GCP

### Authentication

Atmos supports GCP authentication for local development and CI/CD pipelines.

**File:** `atmos.yaml`

```yaml
auth:
  providers:
    gcp-adc:
      kind: gcp/adc
      project_id: my-gcp-project
      region: us-central1

  identities:
    dev-project:
      kind: gcp/service-account
      via:
        provider: gcp-adc
      principal:
        email: deployer@my-gcp-project.iam.gserviceaccount.com
```

**Providers:** `gcp/adc`, `gcp/workload-identity-federation`
**Identities:** `gcp/service-account`, `gcp/project`

### Stores

- **Google Secret Manager:** `google-secret-manager`

### Terraform Backend

- **Google Cloud Storage (GCS)** — Remote state with native locking

**Learn more:** [Auth Providers](/cli/configuration/auth/providers) · [Identities](/cli/configuration/auth/identities) · [Stores](/cli/configuration/stores)

## AWS Reference Architecture

[Cloud Posse](https://cloudposse.com) provides a commercial [reference architecture](https://cloudposse.com/accelerator) built on top of Atmos for AWS. If you're using AWS, this is the fastest way to get started with a production-ready foundation that includes hundreds of pre-built components, proven design patterns, and ongoing support.

**Ready to get started?**

Try Atmos with your cloud provider of choice. The quick start guide walks you through your first deployment.