Render Blueprints (render.yaml)

Blueprints define Render infrastructure as YAML (commonly render.yaml at the repo root). This skill focuses on authoring, wiring, projects/environments, previews, validation, and immutable fields. Heavy detail lives under references/.

When to Use

Apply this skill when the user:

• Creates or edits a render.yaml / Blueprint
• Wires databases, private services, or Key Value into app env vars
• Groups services with projects and environments
• Configures preview environments for pull requests
• Validates YAML against Render’s schema or CLI
• Asks what can or cannot change after a resource is created

For end-to-end deploy flows and MCP/CLI operations, see render-deploy. For env var strategy outside Blueprint syntax, see render-env-vars. For Docker-specific Blueprint fields, see render-docker.

Blueprint Structure

Top-level keys

A Blueprint may also use patterns like ungrouped resources vs environment-scoped lists, depending on whether you adopt the projects model. Avoid duplicating the same logical resource in multiple places (see references/common-mistakes.md).

Schema and IDE validation

• JSON Schema URL: https://render.com/schema/render.yaml.json
• Configure your editor to associate render.yaml with that schema for completions and diagnostics.

Minimal example: web + PostgreSQL

databases:
  - name: mydb
    plan: basic-256mb
    region: oregon

services:
  - type: web
    name: api
    runtime: node
    region: oregon
    plan: starter
    buildCommand: npm ci && npm run build
    startCommand: npm start
    envVars:
      - key: DATABASE_URL
        fromDatabase:
          name: mydb
          property: connectionString

Service Types

Runtimes

Common runtime values: node, python, go, ruby, rust, elixir, docker, image, static.

• docker: Build from Dockerfile (see dockerfilePath, dockerContext, dockerCommand).
• image: Run a prebuilt container image with image.url and optional image.creds.fromRegistryCreds.
• static: Static site; requires staticPublishPath and build output paths (see references).

Cross-Service Wiring

Service env vars under envVars can pull values from other resources instead of hardcoding secrets. Environment-group variables cannot reference services, databases, or other environment groups.

fromDatabase

Reference a database in databases: by name. Properties include:

• connectionString, host, port, user, password, database

fromService

Reference a service by name. Typical properties:

• host, port, hostport, connectionString, envVarKey

Which properties are valid depends on target service type (e.g. Key Value vs pserv). See references/wiring-patterns.md.

fromGroup

Attach shared vars from envVarGroups (by group name).

Other env var keys

• value: Literal string.
• generateValue: Let Render generate a random secret (password/API key).
• sync: Set sync: false for secrets that should not sync from repo on every update (see edge cases in wiring reference).

Full patterns and combinations: references/wiring-patterns.md.

Projects and Environments

For multi-service apps, use the projects/environments pattern instead of flat top-level services/databases. This groups all related resources into a single Render project, supports multiple environments (production, staging), and enables environment-scoped configuration.

projects:
  - name: my-app
    environments:
      - name: production
        services:
          - type: web
            name: api
            runtime: node
            plan: standard
            buildCommand: npm ci && npm run build
            startCommand: npm start
            envVars:
              - key: DATABASE_URL
                fromDatabase:
                  name: db
                  property: connectionString
              - key: REDIS_URL
                fromService:
                  type: keyvalue
                  name: cache
                  property: connectionString
              - key: API_SECRET
                sync: false

          - type: worker
            name: jobs
            runtime: node
            plan: starter
            buildCommand: npm ci
            startCommand: node worker.js
            envVars:
              - key: DATABASE_URL
                fromDatabase:
                  name: db
                  property: connectionString
              - key: REDIS_URL
                fromService:
                  type: keyvalue
                  name: cache
                  property: connectionString

          - type: keyvalue
            name: cache
            plan: starter
            maxmemoryPolicy: noeviction
            ipAllowList: [] # Internal access only

        databases:
          - name: db
            plan: basic-256mb

Key rules:

• Each environment owns its services and databases lists.
• Do not define the same resource at both the root level and inside an environment.
• envVarGroups can be scoped to a project environment or shared across the workspace.
• With a Pro workspace or higher, environment isolation can block cross-environment private network traffic.

For single-service apps, flat top-level services/databases is fine. Reach for the projects pattern when you have multiple services, need staging/production separation, or want environment-scoped env groups.

Preview Environments

Top-level previews controls Blueprint preview environments:

• previews.generation: off (default), manual, or automatic
• previews.expireAfterDays: Auto-delete preview stacks after N days

Do not confuse preview environments with service previews. A service-level previews.generation setting controls that service's independent pull request previews and does not override preview-environment generation; it accepts only manual or automatic, and omission disables service previews. Within the same service-level object, previews.plan and previews.numInstances size the service in preview environments. Key Value and Postgres use previewPlan instead. Limitations: autoscaling behavior, sync: false vars, and flexible database instance constraints—see references/preview-environments.md.

Validation

render blueprints validate

Requires Render CLI v2.7.0+. Run from the repo root (or pass the appropriate path options your CLI version supports). Fix schema and semantic errors before merging Blueprint changes.

Official schema: https://render.com/schema/render.yaml.json

Immutable Fields

CRITICAL: Some fields cannot change after the resource is created. Edits may be rejected or require replacement resources.

Services

• type: Cannot change (e.g. web → worker).
• runtime: Cannot change (e.g. node → docker).

Databases

Cannot change after creation:

• name (logical Blueprint/database identifier in this context)
• databaseName
• user
• region
• postgresMajorVersion

Plan other fields (disk, HA, replicas) carefully up front; consult Render docs for fields that can scale vs require recreation.

Key Fields (Quick Map)

Deprecated names to avoid: env (use runtime), redis (use keyvalue), autoDeploy (use autoDeployTrigger), previewsEnabled, and pullRequestPreviewsEnabled. Use the appropriate top-level or service-level previews.generation replacement described in references/common-mistakes.md.

References

Related Skills

• render-deploy — Deploy flows, Blueprint vs direct create, MCP/deeplinks
• render-env-vars — Env var strategy, secrets, Dashboard vs Blueprint
• render-docker — Dockerfile-backed services and image runtime nuances