16 KiB
Render Blueprint Specification
Complete reference for render.yaml Blueprint files. Blueprints define your infrastructure as code for reproducible deployments on Render.
Overview
A Blueprint is a YAML file (typically render.yaml) placed in your repository root that describes:
- Services (web, worker, cron, static, private)
- Databases (PostgreSQL, Redis)
- Environment variables and secrets
- Scaling and resource configuration
- Project organization
Root-Level Structure
# Top-level fields
services: [] # Array of service definitions
databases: [] # Array of PostgreSQL databases
envVarGroups: [] # Reusable environment variable groups (optional)
projects: [] # Project organization (optional)
ungrouped: [] # Resources outside projects (optional)
previews: # Preview environment configuration (optional)
generation: auto_preview | manual | none
Service Types
Web Services (type: web)
HTTP services, APIs, and web applications. Publicly accessible via HTTPS.
Required fields:
name: Unique service identifiertype: Must bewebruntime: Language/environment (see Runtimes section)buildCommand: Command to build the applicationstartCommand: Command to start the server
Common optional fields:
plan: Instance type (default:free)region: Deployment region (default:oregon)branch: Git branch to deploy (default:main)autoDeploy: Auto-deploy on push (default:true)envVars: Environment variables arrayhealthCheckPath: Health check endpoint (default:/)numInstances: Number of instances (manual scaling)scaling: Autoscaling configuration
Example:
services:
- type: web
name: api-server
runtime: node
plan: free
buildCommand: npm ci
startCommand: npm start
branch: main
autoDeploy: true
envVars:
- key: NODE_ENV
value: production
- key: PORT
value: 10000
Worker Services (type: worker)
Background job processors, queue consumers. Not publicly accessible.
Required fields:
name: Unique service identifiertype: Must beworkerruntime: Language/environmentbuildCommand: Command to buildstartCommand: Command to start worker process
Key differences from web services:
- No public URL
- No health checks
- No port binding required
Example:
services:
- type: worker
name: job-processor
runtime: python
plan: free
buildCommand: pip install -r requirements.txt
startCommand: celery -A tasks worker --loglevel=info
envVars:
- key: REDIS_URL
fromDatabase:
name: redis
property: connectionString
Cron Jobs (type: cron)
Scheduled tasks that run on a cron schedule.
Required fields:
name: Unique service identifiertype: Must becronruntime: Language/environmentschedule: Cron expressionbuildCommand: Command to buildstartCommand: Command to execute on schedule
Schedule format: Standard cron syntax (minute hour day month weekday)
Examples:
0 0 * * *- Daily at midnight UTC*/15 * * * *- Every 15 minutes0 9 * * 1- Every Monday at 9 AM UTC
Example:
services:
- type: cron
name: daily-backup
runtime: node
schedule: "0 2 * * *"
buildCommand: npm ci
startCommand: node scripts/backup.js
envVars:
- key: DATABASE_URL
fromDatabase:
name: postgres
property: connectionString
Static Sites (type: static or type: web with runtime: static)
Serve static HTML/CSS/JS files via CDN.
Required fields:
name: Unique service identifiertype:webruntime:staticbuildCommand: Command to build static assetsstaticPublishPath: Path to built files (e.g.,./build,./dist)
Optional configuration:
routes: Routing rules for SPAsheaders: Custom HTTP headersbuildFilter: Path filters for build triggers
Example:
services:
- type: web
name: react-app
runtime: static
buildCommand: npm ci && npm run build
staticPublishPath: ./dist
routes:
- type: rewrite
source: /*
destination: /index.html
headers:
- path: /*
name: Cache-Control
value: public, max-age=31536000, immutable
Private Services (type: pserv)
Internal services accessible only within your Render account.
Required fields:
name: Unique service identifiertype: Must bepservruntime: Language/environmentbuildCommand: Command to buildstartCommand: Command to start
Use cases:
- Internal APIs
- Database proxies
- Microservices not exposed to internet
Example:
services:
- type: pserv
name: internal-api
runtime: go
plan: free
buildCommand: go build -o bin/app
startCommand: ./bin/app
Runtimes
Native Runtimes
Node.js (runtime: node):
- Versions: 14, 16, 18, 20, 21
- Default version: 20
- Specify version in
package.jsonengines field
Python (runtime: python):
- Versions: 3.8, 3.9, 3.10, 3.11, 3.12
- Default version: 3.11
- Specify version in
runtime.txtorPipfile
Go (runtime: go):
- Versions: 1.20, 1.21, 1.22, 1.23
- Uses go modules
- Version from
go.mod
Ruby (runtime: ruby):
- Versions: 3.0, 3.1, 3.2, 3.3
- Uses Bundler
- Version from
.ruby-versionorGemfile
Rust (runtime: rust):
- Latest stable version
- Uses Cargo
Elixir (runtime: elixir):
- Latest stable version
- Uses Mix
Docker Runtime
Docker (runtime: docker):
Build from a Dockerfile in your repository.
Additional fields:
dockerfilePath: Path to Dockerfile (default:./Dockerfile)dockerContext: Build context directory (default:.)
Example:
services:
- type: web
name: docker-app
runtime: docker
dockerfilePath: ./docker/Dockerfile
dockerContext: .
plan: free
Image (runtime: image):
Deploy pre-built Docker images from a registry.
Additional fields:
image: Image URL (e.g.,registry.com/image:tag)registryCredential: Credentials for private registries
Example:
services:
- type: web
name: prebuilt-app
runtime: image
image: myregistry.com/app:v1.2.3
plan: free
Service Plans
Available instance types:
| Plan | RAM | CPU | Price |
|---|---|---|---|
free |
512 MB | 0.5 | Free (750 hrs/mo) |
starter |
512 MB | 0.5 | $7/month |
standard |
2 GB | 1 | $25/month |
pro |
4 GB | 2 | $85/month |
pro_plus |
8 GB | 4 | $175/month |
Always default to plan: free unless user specifies otherwise.
Regions
Available deployment regions:
oregon(US West) - Defaultohio(US East)virginia(US East)frankfurt(EU)singapore(Asia)
Example:
services:
- type: web
name: my-app
runtime: node
region: frankfurt
Environment Variables
Three patterns for defining environment variables:
1. Hardcoded Values
For non-sensitive configuration:
envVars:
- key: NODE_ENV
value: production
- key: API_URL
value: https://api.example.com
- key: LOG_LEVEL
value: info
2. Generated Secrets
Render generates a base64-encoded 256-bit random value:
envVars:
- key: SESSION_SECRET
generateValue: true
- key: ENCRYPTION_KEY
generateValue: true
3. User-Provided Secrets
Prompt user for values during Blueprint creation:
envVars:
- key: STRIPE_SECRET_KEY
sync: false
- key: JWT_SECRET
sync: false
- key: API_KEY
sync: false
The sync: false flag means "user will fill this in the Dashboard".
4. Database References
Link to database connection strings:
envVars:
- key: DATABASE_URL
fromDatabase:
name: postgres
property: connectionString
- key: REDIS_URL
fromDatabase:
name: redis
property: connectionString
Available properties:
connectionString: Full connection URLhost: Database hostport: Database portuser: Database usernamepassword: Database passworddatabase: Database namehostport: Combinedhost:port
5. Service References
Link to other services:
envVars:
- key: API_URL
fromService:
name: api-server
type: web
property: host
6. Environment Variable Groups
Reusable groups shared across services:
envVarGroups:
- name: shared-config
envVars:
- key: LOG_LEVEL
value: info
- key: ENVIRONMENT
value: production
services:
- type: web
name: web-app
runtime: node
envVars:
- fromGroup: shared-config
- key: PORT
value: 10000
Databases
PostgreSQL
databases:
- name: postgres
databaseName: myapp_prod
user: myapp_user
plan: free
postgresMajorVersion: "15"
ipAllowList: []
Plans:
free: 1 GB storage, 97 MB RAM, 0.1 CPUbasic-256mb,basic-512mb,basic-1gb,basic-4gbpro-4gb,pro-8gb,pro-16gb, etc.accelerated-4gb,accelerated-8gb, etc. (SSD-backed)
Key fields:
name: Identifier for referencesdatabaseName: Actual PostgreSQL database nameuser: Database usernamepostgresMajorVersion: PostgreSQL version (11-16)ipAllowList: Array of CIDR blocks (empty = internal only)diskSizeGB: Storage size (paid plans only)
High Availability (paid plans):
databases:
- name: postgres
databaseName: myapp_prod
plan: pro-4gb
highAvailabilityEnabled: true
Read Replicas (paid plans):
databases:
- name: postgres
databaseName: myapp_prod
plan: pro-4gb
readReplicas:
- name: read-replica-1
region: ohio
- name: read-replica-2
region: frankfurt
Redis (Key-Value Store)
databases:
- name: redis
plan: free
maxmemoryPolicy: allkeys-lru
ipAllowList: []
Plans: Same as PostgreSQL
maxmemoryPolicy options:
allkeys-lru: Evict least recently used keysvolatile-lru: Evict LRU keys with TTLallkeys-random: Evict random keysvolatile-random: Evict random keys with TTLvolatile-ttl: Evict keys with soonest TTLnoeviction: Return errors when memory full
Scaling
Manual Scaling
Fixed number of instances:
services:
- type: web
name: my-app
runtime: node
plan: standard
numInstances: 3
Autoscaling
Dynamic scaling based on CPU/memory (Professional workspace required):
services:
- type: web
name: my-app
runtime: node
plan: standard
scaling:
minInstances: 1
maxInstances: 5
targetCPUPercent: 60
targetMemoryPercent: 70
Notes:
- Autoscaling disabled in preview environments
- Preview environments run
minInstancescount - Requires Professional or higher workspace
Health Checks
Configure health check endpoints:
services:
- type: web
name: my-app
runtime: node
healthCheckPath: /health
Default: / (root path)
Recommended: Add a dedicated /health endpoint that returns 200 OK.
Build Filters
Control when builds are triggered based on changed files:
services:
- type: web
name: frontend
runtime: static
buildFilter:
paths:
- frontend/**
ignoredPaths:
- frontend/README.md
- frontend/**/*.test.js
Behavior:
- If
pathsspecified: Build only when files in those paths change - If
ignoredPathsspecified: Don't build when only ignored files change
Projects and Environments
Organize services into projects with multiple environments:
projects:
- name: my-application
environments:
- name: production
services:
- type: web
name: prod-api
runtime: node
plan: pro
buildCommand: npm ci
startCommand: npm start
databases:
- name: prod-postgres
plan: pro-4gb
networking:
isolation: enabled
permissions:
protection: enabled
- name: staging
services:
- type: web
name: staging-api
runtime: node
plan: starter
buildCommand: npm ci
startCommand: npm start
databases:
- name: staging-postgres
plan: free
Environment features:
networking.isolation: Enable network isolation between environmentspermissions.protection: Require approval for environment changes
Preview Environments
Configure automatic preview environments for pull requests:
previews:
generation: auto_preview # auto_preview | manual | none
Options:
auto_preview: Create preview environment for each PR automaticallymanual: User manually triggers preview creationnone: Disable preview environments
Complete Example
Full-featured Blueprint with multiple services and databases:
services:
# Web service
- type: web
name: web-app
runtime: node
plan: free
region: oregon
buildCommand: npm ci && npm run build
startCommand: npm start
branch: main
autoDeploy: true
healthCheckPath: /health
envVars:
- key: NODE_ENV
value: production
- key: DATABASE_URL
fromDatabase:
name: postgres
property: connectionString
- key: REDIS_URL
fromDatabase:
name: redis
property: connectionString
- key: JWT_SECRET
sync: false
# Background worker
- type: worker
name: queue-worker
runtime: node
plan: free
buildCommand: npm ci
startCommand: node worker.js
envVars:
- key: REDIS_URL
fromDatabase:
name: redis
property: connectionString
# Cron job
- type: cron
name: daily-cleanup
runtime: node
schedule: "0 3 * * *"
buildCommand: npm ci
startCommand: node scripts/cleanup.js
envVars:
- key: DATABASE_URL
fromDatabase:
name: postgres
property: connectionString
# Static frontend
- type: web
name: frontend
runtime: static
buildCommand: npm ci && npm run build
staticPublishPath: ./dist
routes:
- type: rewrite
source: /*
destination: /index.html
databases:
- name: postgres
databaseName: app_production
user: app_user
plan: free
postgresMajorVersion: "15"
ipAllowList: []
- name: redis
plan: free
maxmemoryPolicy: allkeys-lru
ipAllowList: []
Validation
Validate your Blueprint before deploying (when CLI command is available):
render blueprint validate
Common validation errors:
- Missing required fields
- Invalid runtime values
- Incorrect environment variable references
- Invalid cron expressions
- Invalid YAML syntax
Best Practices
- Always use
plan: freeby default - Let users upgrade if needed - Mark all secrets with
sync: false- Never hardcode sensitive values - Use
fromDatabasefor database URLs - Automatic internal connection strings - Add health check endpoints - Faster deployment detection
- Use non-interactive build commands - Prevents build hangs
- Bind to
0.0.0.0:$PORT- Required for web services - Use environment variable groups - Share config across services
- Enable autoDeploy: true - Deploy automatically on push
- Set appropriate regions - Choose closest to your users
- Use build filters - Optimize build triggers in monorepos
Additional Resources
- Official Blueprint Specification: https://render.com/docs/blueprint-spec
- Render CLI Documentation: https://render.com/docs/cli
- Environment Variables Guide: https://render.com/docs/environment-variables