Environment

# Environment Configuration

Read and edit Railway environment configuration using the CLI.

## Prerequisites

Requires Railway CLI **v4.27.3+**. Check with:
```bash
railway --version
```

If below 4.27.3, upgrade:
```bash
railway upgrade
```

## Quick Actions

**When user asks "what's the config" or "show configuration":**

```bash
railway environment config --json
```

Present: source (repo/image), build settings, deploy settings, variables per service.

**When user asks "what variables" or "show env vars":**

Same command — `railway environment config --json` includes variables per service and shared variables.

For **rendered** (resolved) variable values: `railway variables --json`

## When to Use

- User wants to create a new environment
- User wants to duplicate an environment (e.g., "copy production to staging")
- User wants to switch to a different environment
- User asks about current build/deploy settings, variables, replicas, health checks, domains
- User asks to change service source (Docker image, branch, commit, root directory)
- User wants to connect a service to a GitHub repo
- User wants to deploy from a GitHub repo (create empty service first via `new` skill, then use this)
- User asks to change build or start command
- User wants to add/update/delete environment variables
- User wants to change replica count or configure health checks
- User asks to delete a service, volume, or bucket
- Auto-fixing build errors detected in logs

## Create Environment

Create a new environment in the linked project:

```bash
railway environment new <name>
```

Duplicate an existing environment:

```bash
railway environment new staging --duplicate production
```

With service-specific variables:

```bash
railway environment new staging --duplicate production --service-variable api PORT=3001
```

## Switch Environment

Link a different environment to the current directory:

```bash
railway environment <name>
```

Or by ID:

```bash
railway environment <environment-id>
```

## Get Context

**JSON output** — project/environment IDs and service list:
```bash
railway status --json
```

Extract:
- `project.id` — project ID
- `environment.id` — environment ID

**Plain output** — linked service name:
```bash
railway status
```

Shows `Service: <name>` line with the currently linked service.

### Resolve Service ID

Get service IDs from the environment config:
```bash
railway environment config --json | jq '.services | keys'
```

Map service IDs to names via status:
```bash
railway status --json
```

The `project.services` array contains `{ id, name }` for each service. Match against the service keys from `environment config`.

## Read Configuration

Fetch current environment configuration:

```bash
railway environment config --json
```

### Response Structure

```json
{
  "services": {
    "<serviceId>": {
      "source": { "repo": "...", "branch": "main" },
      "build": { "buildCommand": "npm run build", "builder": "NIXPACKS" },
      "deploy": {
        "startCommand": "npm start",
        "multiRegionConfig": { "us-west2": { "numReplicas": 1 } }
      },
      "variables": { "NODE_ENV": { "value": "production" } },
      "networking": { "serviceDomains": {}, "customDomains": {} }
    }
  },
  "sharedVariables": { "DATABASE_URL": { "value": "..." } }
}
```

For complete field reference, see [reference/environment-config.md](references/environment-config.md).

For variable syntax and service wiring patterns, see [reference/variables.md](references/variables.md).

## Get Rendered Variables

`environment config` returns **unrendered** variables — template syntax like `${{