atmos-config

name	atmos-config
description	Atmos root configuration: atmos.yaml discovery, precedence, deep merging, base_path, imports, minimal bootstrap, and routing to narrower Atmos skills
metadata	{"copyright":"Copyright Cloud Posse, LLC 2026","version":"1.0.0","category":"core-config"}
references	["references/sections-reference.md"]

Atmos Root Configuration

Use this skill for the root mechanics of atmos.yaml: how Atmos finds config files, merges them, resolves project-relative paths, imports modular config, and routes section-specific work to the right skill. Do not use this skill as a catchall for every atmos.yaml section.

Configuration Discovery

Atmos searches for atmos.yaml in this order:

1. --config CLI flag or ATMOS_CLI_CONFIG_PATH.
2. Active profile selected by --profile or ATMOS_PROFILE.
3. Current working directory.
4. Git repository root.
5. Parent directory walk.
6. Home directory.
7. System directory.

When multiple configuration files apply, Atmos deep-merges them. More specific sources override broader defaults.

Root Layout

Use base_path for the project root that relative paths resolve from. Keep the root config small and point subsystem paths at their owning directories:

base_path: ""

stacks:
  base_path: stacks
  included_paths:
    - "**/*"
  excluded_paths:
    - "**/_defaults.yaml"
    - "catalog/**/*"
  name_template: "{{ .vars.stage }}"

components:
  terraform:
    base_path: components/terraform

workflows:
  base_path: stacks/workflows

For deeper path/layout guidance, load atmos-project-layout.

Modular Imports

Use import to split root config into focused files:

import:
  - atmos.d/stacks.yaml
  - atmos.d/components.yaml
  - atmos.d/auth.yaml
  - atmos.d/toolchain.yaml

Imported files are deep-merged into the active configuration. Keep imported files aligned with the subsystem they configure and load the subsystem skill before changing that section.

Routing

Need	Load
Root discovery, merge order, imports, minimal bootstrap	stay in atmos-config
Project paths, base_path, path conventions, relative path resolution	atmos-project-layout
Profiles, --profile, ATMOS_PROFILE, profile directory merge behavior	atmos-profiles
Global CLI behavior, settings, logs, errors, env, docs, metadata	atmos-settings
Stack manifests, inheritance, stack imports, vars, locals, stack naming	atmos-stacks
Component structure, abstract components, metadata, component inheritance	atmos-components
Terraform/OpenTofu commands, backend defaults, Terraform component settings	atmos-terraform
Helmfile, Packer, or Ansible component behavior	atmos-helmfile, atmos-packer, atmos-ansible
Workflows section and workflow syntax	atmos-workflows
Custom commands and aliases	atmos-custom-commands
Auth providers, identities, keyring, cloud auth conventions	atmos-auth
Stores and store-backed YAML functions	atmos-stores
Tool versions, dependencies.tools, registries, shell/PATH integration	atmos-toolchain
Native CI, GitHub Actions, Atlantis, matrices, CI outputs	atmos-ci
Schemas and validation policy configuration	atmos-schemas, atmos-validation
Templates and YAML functions	atmos-templates, atmos-yaml-functions

For a compact map of top-level sections, read references/sections-reference.md.

Guardrails

• Keep atmos-config examples minimal; detailed subsystem examples belong in their narrower skills.
• Before editing a subsystem section, load the owning skill from the routing table.
• Prefer atmos describe config or atmos describe component when verifying merge or path behavior.