# atmos list vars

Use this command to list component variables across all stacks in a comparison table. View how Terraform variables vary between environments to quickly identify configuration differences and validate consistency.

_\[Video: atmos list vars]_

## Usage

```shell
atmos list vars <component> [flags]
```

## Description

The `atmos list vars` command helps you inspect component variables across different stacks. It provides a tabular view where:

- Each column represents a stack (e.g., dev-ue1, staging-ue1, prod-ue1)
- Each row represents a variable in the component's configuration
- Cells contain the variable values for each stack

This command is an alias for `atmos list values --query .vars` and is useful for:

- Comparing component variables across different environments
- Verifying configuration consistency across stacks
- Troubleshooting configuration issues

## Arguments

- **`component`**
  The component to list variables for

## Flags

- **`--query string`**
  Filter the results using YQ expressions (default: 
  `.vars`
  )
- **`--abstract`**
  Include abstract components
- **`--max-columns int`**
  Maximum number of columns to display (default: 
  `50`
  )
- **`--format string`**
  Output format: 
  `table`
  , 
  `json`
  , 
  `yaml`
  , 
  `csv`
  , 
  `tsv`
   (default: 
  `table`
  )
- **`--delimiter string`**
  Delimiter for csv/tsv output (default: 
  `,`
   for csv, 
  `\t`
   for tsv)
- **`--stack string`**
  Filter by stack pattern (e.g., 
  `*-dev-*`
  , 
  `prod-*`
  , 
  `*-{dev,staging}-*`
  )
- **`--identity` / `-i` (optional)**
  Authenticate with a specific identity before listing vars.
  This is required when stack configurations use YAML template functions
  (e.g., 
  `!terraform.state`
  , 
  `!terraform.output`
  ) that require authentication.
  `atmos list vars vpc --identity my-aws-identity`
  Can also be set via 
  `ATMOS_IDENTITY`
   environment variable.
- **`--process-templates`**
  Enable/disable Go template processing in Atmos stack manifests (default 
  `true`
  ). Go template functions include 
  `atmos.Component(...)`
  .
  Environment variable: 
  `ATMOS_PROCESS_TEMPLATES`
- **`--process-functions`**
  Enable/disable YAML functions processing in Atmos stack manifests (default 
  `true`
  ). YAML functions include 
  `!terraform.state`
  , 
  `!terraform.output`
  , 
  `!store`
  , 
  `!aws.*`
  , etc. This is distinct from Go template functions like 
  `atmos.Component(...)`
  , which are controlled by 
  `--process-templates`
  .
  Environment variable: 
  `ATMOS_PROCESS_FUNCTIONS`

## Examples

List all variables for a component:

```shell
atmos list vars vpc
```

List specific variables using query:

```shell
# List specific variable
atmos list vars vpc --query .vars.tags

# List a nested variable
atmos list vars vpc --query .vars.settings.vpc
```

Filter by stack pattern:

```shell
# List variables for dev stacks
atmos list vars vpc --stack '*-dev-*'

# List variables for production stacks
atmos list vars vpc --stack 'prod-*'
```

Output in different formats:

```shell
# JSON format for machine processing
atmos list vars vpc --format json

# YAML format for configuration files
atmos list vars vpc --format yaml

# CSV format for spreadsheet compatibility
atmos list vars vpc --format csv

# TSV format with tab delimiters
atmos list vars vpc --format tsv
```

Include abstract components:

```shell
atmos list vars vpc --abstract
```

Filter by stack and specific variables:

```shell
atmos list vars vpc --stack '*-ue2-*' --query .vars.region
```

### Custom Column using Stack Name

You can use available variables like `.stack_name` in your column definitions:

```yaml
# In atmos.yaml, under the appropriate scope (values, vars, settings, or metadata)
list:
  columns:
    - name: "Stack"
      value: "{{ .stack_name }}"
    - name: "Variable"
      value: "{{ .key }}"
    - name: "Value"
      value: "{{ .value }}"
```

## Example Output

```shell
> atmos list vars vpc
┌─────────────┬──────────────┬──────────────┬──────────────┐
│             │   dev-ue1    │  staging-ue1 │   prod-ue1   │
├─────────────┼──────────────┼──────────────┼──────────────┤
│ name        │ platform-vpc │ platform-vpc │ platform-vpc │
│ region      │ us-east-1    │ us-east-1    │ us-east-1    │
│ environment │ dev          │ staging      │ prod         │
└─────────────┴──────────────┴──────────────┴──────────────┘
```

:::tip

- For wide tables, try using more specific queries or reduce the number of stacks
- Stack patterns support glob matching (e.g., `*-dev-*`, `prod-*`, `*-{dev,staging}-*`)
- Use `--abstract` to include abstract components in the results
  :::