Environment Configuration Skill

Environment Configuration

Read and edit Railway environment configuration using the CLI.

Prerequisites

Requires Railway CLI v4.27.3+. Check with:

railway --version

If below 4.27.3, upgrade:

railway upgrade

Quick Actions

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

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:

railway environment new <name>

Duplicate an existing environment:

railway environment new staging --duplicate production

With service-specific variables:

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

Switch Environment

Link a different environment to the current directory:

railway environment <name>

Or by ID:

railway environment <environment-id>

Get Context

JSON output — project/environment IDs and service list:

railway status --json

Extract:

project.id — project ID
environment.id — environment ID

Plain output — linked service name:

railway status

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

Resolve Service ID

Get service IDs from the environment config:

railway environment config --json | jq '.services | keys'

Map service IDs to names via status:

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:

railway environment config --json

Response Structure

{
  "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.

For variable syntax and service wiring patterns, see reference/variables.md.

Get Rendered Variables

environment config returns unrendered variables — template syntax like ${{shared.DOMAIN}} is preserved. This is correct for management/editing.

To see rendered (resolved) values as they appear at runtime:

# Current linked service
railway variables --json

# Specific service
railway variables --service <service-name> --json

When to use:

Debugging connection issues (see actual URLs/ports)
Verifying variable resolution is correct
Viewing Railway-injected values (RAILWAY_*)

Edit Configuration

Pass a JSON patch to railway environment edit to apply changes. The patch is merged with existing config and committed immediately, triggering deploys.

railway environment edit --json <<< '<json-patch>'

With a commit message:

railway environment edit -m "description of change" --json <<< '<json-patch>'

Examples

Set build command:

railway environment edit --json <<< '{"services":{"SERVICE_ID":{"build":{"buildCommand":"npm run build"}}}}'

Add variable:

railway environment edit -m "add API_KEY" --json <<< '{"services":{"SERVICE_ID":{"variables":{"API_KEY":{"value":"secret"}}}}}'

Delete variable:

railway environment edit --json <<< '{"services":{"SERVICE_ID":{"variables":{"OLD_VAR":null}}}}'

Delete service:

railway environment edit --json <<< '{"services":{"SERVICE_ID":{"isDeleted":true}}}'

Set replicas:

railway environment edit --json <<< '{"services":{"SERVICE_ID":{"deploy":{"multiRegionConfig":{"us-west2":{"numReplicas":3}}}}}}'

Add shared variable:

railway environment edit --json <<< '{"sharedVariables":{"DATABASE_URL":{"value":"postgres://..."}}}'

Batching Multiple Changes

Include multiple fields in a single patch to apply them atomically:

railway environment edit -m "configure build, start, and env" --json <<< '{"services":{"SERVICE_ID":{"build":{"buildCommand":"npm run build"},"deploy":{"startCommand":"npm start"},"variables":{"NODE_ENV":{"value":"production"}}}}}'

Error Handling

Command Not Found

If railway environment edit is not recognized, upgrade the CLI:

railway upgrade

Service Not Found

Service "foo" not found in project. Available services: api, web, worker

Invalid Configuration

Common issues:

buildCommand and startCommand cannot be identical
buildCommand only valid with NIXPACKS builder
dockerfilePath only valid with DOCKERFILE builder

No Permission

You don't have permission to modify this environment. Check your Railway role.

No Linked Project

No project linked. Run `railway link` to link a project.

Composability

Create service: Use service skill
View logs: Use deployment skill
Add domains: Use domain skill
Deploy local code: Use deploy skill

Agent Skills: Environment Configuration

Install this agent skill to your local

Skill Files