Providers and Identities Reference

Detailed configuration reference for all authentication providers and identity types supported by Atmos Auth.

Provider Configuration

AWS IAM Identity Center (SSO)

auth:
  providers:
    <name>:
      kind: aws/iam-identity-center        # Required
      region: us-east-1                     # Required: AWS region for Identity Center instance
      start_url: https://company.awsapps.com/start  # Required: SSO start URL
      auto_provision_identities: true       # Optional: auto-discover accounts/permission sets (default: false)
      session:
        duration: 4h                        # Optional: credential lifetime
      console:
        session_duration: 12h               # Optional: web console session (max 12h for AWS)
      spec:
        endpoint_url: http://localhost:4566  # Optional: AWS-compatible base endpoint for Floci/LocalStack
        files:
          base_path: ~/.config/atmos/aws/   # Optional: custom credential file storage path

Auto-provisioning IAM permissions required:

• sso:ListAccounts -- Enumerates all accessible AWS accounts.
• sso:ListAccountRoles -- Lists available permission sets per account.

Without these permissions, auto-provisioning fails gracefully and falls back to manually configured identities.

AWS SAML

auth:
  providers:
    <name>:
      kind: aws/saml                        # Required
      region: us-east-1                     # Required: AWS region
      url: https://company.okta.com/app/amazon_aws/abc123/sso/saml  # Required: SAML SSO URL
      driver: Browser                       # Optional: Browser (default, needs Playwright), GoogleApps, Okta, ADFS

The aws/saml provider requires the next identity in the chain to be aws/assume-role, as the SAML flow requires selecting a role to assume.

GitHub Actions OIDC

auth:
  providers:
    <name>:
      kind: github/oidc                     # Required
      region: us-east-1                     # Required: AWS region for STS endpoint
      spec:
        audience: sts.us-east-1.amazonaws.com  # Optional: defaults to STS endpoint for region

GitHub Actions workflow must have id-token: write permission and should select the CI profile with ATMOS_PROFILE. The cloud IAM trust policy must constrain GitHub OIDC sub claims to the intended repository plus branch or GitHub environment, such as repo:ORG/REPO:ref:refs/heads/main or repo:ORG/REPO:environment:prod.

GCP Application Default Credentials

auth:
  providers:
    <name>:
      kind: gcp/adc                         # Required
      project_id: my-gcp-project            # Optional: override gcloud config default
      region: us-central1                   # Optional: default region
      scopes:                               # Optional: OAuth scopes
        - https://www.googleapis.com/auth/cloud-platform

Requires existing ADC. Run gcloud auth application-default login first.

GCP Workload Identity Federation

auth:
  providers:
    <name>:
      kind: gcp/workload-identity-federation  # Required
      project_id: my-gcp-project              # Optional: GCP project ID
      project_number: "123456789012"          # Required: GCP project number (numeric)
      workload_identity_pool_id: github-pool  # Required: WIF pool ID
      workload_identity_provider_id: github-provider  # Required: WIF provider ID
      service_account_email: ci-sa@my-project.iam.gserviceaccount.com  # Optional: SA to impersonate
      scopes:                                 # Optional: OAuth scopes
        - https://www.googleapis.com/auth/cloud-platform
      token_source:                           # Auto-detected in GitHub Actions
        type: url                             # url, file, or environment
        url: https://my-oidc-provider.example.com/token
        request_token: <bearer-token>         # For type: url
        audience: //iam.googleapis.com/projects/...
        allowed_hosts:
          - my-oidc-provider.example.com
        environment_variable: OIDC_TOKEN      # For type: environment
        file_path: /path/to/token             # For type: file

GitHub Actions auto-detection:

• Sets token_source.type to url.
• Uses ACTIONS_ID_TOKEN_REQUEST_URL as the token endpoint.
• Uses ACTIONS_ID_TOKEN_REQUEST_TOKEN as the bearer token.
• Constructs audience from project_number, workload_identity_pool_id, and workload_identity_provider_id.
• Validates token URL against known GitHub Actions OIDC hosts.

Identity Configuration

AWS Permission Set

auth:
  identities:
    <name>:
      kind: aws/permission-set              # Required
      default: true                         # Optional: use when no identity specified
      via:
        provider: <provider-name>           # Required: SSO provider reference
      principal:
        name: AdminAccess                   # Required: permission set name
        account:
          name: development                 # Account name (resolved via SSO ListAccounts)
          id: "123456789012"                # OR account ID directly (no lookup needed)
      session:
        duration: 4h                        # Optional: override provider session duration

AWS Assume Role

auth:
  identities:
    <name>:
      kind: aws/assume-role                 # Required
      default: false                        # Optional
      via:
        identity: <identity-name>           # Chain from another identity
        # OR
        provider: <provider-name>           # Direct from provider (mutually exclusive)
      principal:
        assume_role: arn:aws:iam::999999999999:role/RoleName  # Required: role ARN
        session_name: atmos-session         # Optional: for CloudTrail auditing

AWS Assume Root

auth:
  identities:
    <name>:
      kind: aws/assume-root                 # Required
      via:
        identity: <identity-name>           # Required: must chain from an existing identity
      principal:
        target_principal: "123456789012"     # Required: 12-digit member account ID
        task_policy_arn: arn:aws:iam::aws:policy/root-task/<PolicyName>  # Required
        duration: 15m                       # Optional: max 15 minutes for AssumeRoot

Supported task policies:

• arn:aws:iam::aws:policy/root-task/IAMAuditRootUserCredentials
• arn:aws:iam::aws:policy/root-task/IAMCreateRootUserPassword
• arn:aws:iam::aws:policy/root-task/IAMDeleteRootUserCredentials
• arn:aws:iam::aws:policy/root-task/S3UnlockBucketPolicy
• arn:aws:iam::aws:policy/root-task/SQSUnlockQueuePolicy

Requires AWS Organizations with centralized root access enabled.

AWS User (Break-glass)

auth:
  identities:
    <name>:
      kind: aws/user                        # Required
      credentials:
        access_key_id: !env AWS_ACCESS_KEY_ID        # Use !env for env var references
        secret_access_key: !env AWS_SECRET_ACCESS_KEY  # Use !env for env var references
        region: us-east-1                            # AWS region
        mfa_arn: arn:aws:iam::123456789012:mfa/user  # Optional: prompts for TOTP
      spec:
        endpoint_url: http://localhost:4566           # Optional: AWS-compatible base endpoint for Floci/LocalStack
      session:
        duration: 1h                        # Optional: 15m-12h (no MFA) or 15m-36h (with MFA)

Store credentials securely with atmos auth user configure --identity <name> instead of in config files.

Azure Subscription

auth:
  identities:
    <name>:
      kind: azure/subscription              # Required
      via:
        provider: <azure-provider-name>     # Required: Azure provider reference
      principal:
        subscription_id: "12345678-1234-1234-1234-123456789012"  # Required
        location: eastus                    # Optional: default Azure region
        resource_group: my-rg               # Optional: default resource group

Sets environment variables: AZURE_SUBSCRIPTION_ID, ARM_SUBSCRIPTION_ID, AZURE_LOCATION, ARM_LOCATION, etc.

GCP Service Account

auth:
  identities:
    <name>:
      kind: gcp/service-account             # Required
      default: true                         # Optional
      via:
        provider: <gcp-provider-name>       # Required: gcp/adc or gcp/workload-identity-federation
      principal:
        service_account_email: tf@my-project.iam.gserviceaccount.com  # Required
        project_id: my-project              # Optional: extracted from email if not set
        scopes:                             # Optional: defaults to cloud-platform
          - https://www.googleapis.com/auth/cloud-platform
        lifetime: 3600s                     # Optional: default 1h, max 12h
        delegates:                          # Optional: multi-hop impersonation chain
          - sa1@project.iam.gserviceaccount.com

Requires the base identity to have roles/iam.serviceAccountTokenCreator on the target service account.

GCP Project

auth:
  identities:
    <name>:
      kind: gcp/project                     # Required
      via:
        provider: <gcp-provider-name>       # Optional
      principal:
        project_id: production-project      # Required: GCP project ID
        region: us-central1                 # Optional: default region
        zone: us-central1-a                 # Optional: default zone

Sets environment variables: GOOGLE_CLOUD_PROJECT, CLOUDSDK_CORE_PROJECT, GOOGLE_CLOUD_REGION, CLOUDSDK_COMPUTE_REGION, GOOGLE_CLOUD_ZONE, CLOUDSDK_COMPUTE_ZONE.

Identity Chaining Patterns

SSO to Cross-Account Role

The most common pattern: authenticate via SSO, then assume a role in another account.

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

  identities:
    base-admin:
      kind: aws/permission-set
      via:
        provider: company-sso
      principal:
        name: AdminAccess
        account:
          name: core-identity

    prod-admin:
      kind: aws/assume-role
      via:
        identity: base-admin
      principal:
        assume_role: arn:aws:iam::999999999999:role/ProductionAdmin

Multi-Hop Role Chain

Chain through multiple roles for progressive access control.

auth:
  identities:
    base:
      kind: aws/permission-set
      via:
        provider: company-sso
      principal:
        name: AdminAccess
        account:
          name: core-identity

    cross-account:
      kind: aws/assume-role
      via:
        identity: base
      principal:
        assume_role: arn:aws:iam::111111111111:role/CrossAccountRole

    restricted:
      kind: aws/assume-role
      via:
        identity: cross-account
      principal:
        assume_role: arn:aws:iam::111111111111:role/RestrictedRole

SAML to Assume Role

SAML provider always requires an aws/assume-role as the next identity.

auth:
  providers:
    okta:
      kind: aws/saml
      region: us-east-1
      url: https://company.okta.com/app/amazon_aws/abc123/sso/saml

  identities:
    admin:
      kind: aws/assume-role
      via:
        provider: okta
      principal:
        assume_role: arn:aws:iam::123456789012:role/AdminRole

GitHub OIDC for CI/CD

Authenticate GitHub Actions runners without static credentials.

auth:
  providers:
    github-oidc:
      kind: github/oidc
      region: us-east-1

  identities:
    deploy:
      kind: aws/assume-role
      default: true
      via:
        provider: github-oidc
      principal:
        assume_role: arn:aws:iam::123456789012:role/GitHubActionsRole

In GitHub Actions, do not add a routine atmos auth login step for OIDC jobs. Atmos resolves credentials when the command runs.

GCP WIF with Service Account Impersonation

Federate from GitHub Actions OIDC into GCP, then impersonate a service account.

auth:
  providers:
    gcp-wif:
      kind: gcp/workload-identity-federation
      project_number: "123456789012"
      workload_identity_pool_id: github-pool
      workload_identity_provider_id: github-provider

  identities:
    terraform:
      kind: gcp/service-account
      default: true
      via:
        provider: gcp-wif
      principal:
        service_account_email: terraform@my-project.iam.gserviceaccount.com

Chain Rules

• Chains can be arbitrarily deep: provider -> identity -> identity -> ... -> identity.
• via.provider and via.identity are mutually exclusive on any given identity.
• aws/user identities do not require a via field (they have inline credentials).
• Circular dependencies are detected at validation time and rejected with an error.
• Only one identity should be marked default: true. Multiple defaults trigger interactive selection.

Session Configuration

Session durations can be configured at the provider level and overridden at the identity level.

Identity Kind	Duration Range	Notes
AWS Permission Set	Provider default	Controlled by SSO admin
AWS Assume Role	15m-12h	Standard STS limits
AWS Assume Root	Max 15m	AWS-enforced hard limit
AWS User (no MFA)	15m-12h	Standard STS limits
AWS User (with MFA)	15m-36h	Extended with MFA
GCP Service Account	Up to 12h	Default 1h

Component-Level Overrides

Override authentication at the component level in stack configuration. Component auth is deep-merged with global auth. Component identities override global identities with the same name.

components:
  terraform:
    myapp:
      auth:
        identities:
          custom-role:
            kind: aws/assume-role
            via:
              provider: company-sso
            principal:
              assume_role: arn:aws:iam::123456789012:role/MyAppRole

Profiles for Multi-Environment Auth

Use Atmos profiles to swap provider implementations while keeping the same provider name. Identity configurations reference a consistent provider name that behaves differently per profile. For profile directory layout, activation, and merge behavior, see atmos-profiles.

profiles/
  developer/auth.yaml    # SSO with standard sessions
  ci/auth.yaml           # GitHub OIDC for pipelines
  platform/auth.yaml     # SSO with extended sessions

Activate with --profile flag or ATMOS_PROFILE environment variable:

atmos --profile developer auth login
ATMOS_PROFILE=ci atmos terraform apply myapp -s prod

ECR Integration Configuration

auth:
  integrations:
    <name>:
      kind: aws/ecr                        # Required
      via:
        identity: <identity-name>           # Required: identity providing AWS credentials
      spec:
        auto_provision: true                # Optional: auto-trigger on identity login (default: true)
        registry:
          account_id: "123456789012"        # Required: AWS account ID for ECR registry
          region: us-east-2                 # Required: AWS region for ECR registry

ECR tokens expire after approximately 12 hours (AWS-enforced). Credentials are written to ~/.docker/config.json. Integration failures during atmos auth login are non-blocking.

Atmos Pro GitHub STS

Use atmos/pro plus github/sts when CI needs private GitHub access for remote imports, component source:, vendoring, Terraform modules, or managed Git operations.

auth:
  providers:
    atmos-pro:
      kind: atmos/pro
      spec:
        workspace_id: !env ATMOS_PRO_WORKSPACE_ID
  identities:
    atmos-pro:
      kind: atmos/pro
      via:
        provider: atmos-pro
  integrations:
    github-sts:
      kind: github/sts
      via:
        provider: atmos-pro
      spec:
        auto_provision: true
        repos: [acme/modules]
        policy_name: default
        git_config_mode: env
        revoke_on_exit: true
        token_env: ATMOS_PRO_GITHUB_TOKEN

In GitHub Actions, grant permissions.id-token: write. In CI, Atmos can lazily provision github/sts before the first private remote read; an explicit atmos auth login is not required for normal remote import/source/vendor reads when auto_provision is enabled.

Keyring Configuration

System Keyring (Default)

auth:
  keyring:
    type: system

Uses OS-native secure storage: macOS Keychain, Linux Secret Service (GNOME Keyring, KDE Wallet), Windows Credential Manager.

File Keyring

auth:
  keyring:
    type: file
    spec:
      path: ~/.atmos/keyring                # Optional: custom path (default: XDG data directory)
      password_env: ATMOS_KEYRING_PASSWORD   # Optional: env var for password

AES-256 encrypted. Password resolution: env var, then interactive prompt, then error.

Memory Keyring

auth:
  keyring:
    type: memory

No persistence. Credentials lost on exit. Best for testing only.

Logging Configuration

auth:
  logs:
    level: Info                             # Debug, Info, Warn, Error
    file: /var/log/atmos-auth.log           # Optional: path to log file

Auth logs are separate from main Atmos logs. Debug level includes provider initialization, token refresh, credential resolution steps, and API call details (without secrets).