Render Private Services
Private services are identical to web services except they have no public URL. They are reachable only by other Render services on the same private network (same region + workspace). Use them for internal APIs, microservices, gRPC servers, sidecar processes, and anything that should never face the internet.
When to Use
- Building an internal API or microservice behind a public gateway
- Running a gRPC, TCP, or other non-HTTP server that only your services call
- Deploying infrastructure components (Elasticsearch, ClickHouse, RabbitMQ)
- Choosing between a private service and a background worker
For public-facing HTTP services, use render-web-services. For services that don't receive any traffic, use render-background-workers.
Before configuring or troubleshooting private connectivity, read references/private-networking.md.
Before attaching or changing a persistent disk, read references/persistent-disks.md.
When choosing between a private service, web service, and worker, read references/service-types.md.
Private Service vs Background Worker
| Criterion | Private Service | Background Worker |
|---|---|---|
| Binds to a port | Yes (required) | No |
| Receives private network traffic | Yes | No |
| Sends outbound traffic | Yes | Yes |
| Has internal hostname | Yes | No |
| Use case | Internal APIs, gRPC, TCP servers | Queue consumers, async processors |
Rule of thumb: If the process listens on a port and other services call it, it's a private service. If it pulls work from a queue and never receives requests, it's a background worker.
How Private Services Work
- No
onrender.comsubdomain—not reachable from the internet - Reachable at
<service-name>:<port>on the private network by services in the same region and workspace - Can listen on any port (except restricted system ports)—not limited to HTTP or port 10000
- Supports any protocol: HTTP, gRPC, TCP, WebSocket, custom binary protocols
- Same build/deploy lifecycle as web services (build command, start command, pre-deploy)
- Supports persistent disks and Docker runtime. A disk-backed private service stays single-instance and cannot use autoscaling or zero-downtime deploys; follow
references/persistent-disks.mdfor details.
Connecting to a Private Service
Other services reference a private service via its internal hostname and port:
http://<service-name>:<port>
In Blueprints, wire the address using fromService:
yaml- key: INTERNAL_API_URL fromService: name: my-api type: pserv property: hostport
Available fromService properties for pserv:
| Property | Value |
|---|---|
host | Internal hostname (e.g. my-api) |
port | Port the service listens on |
hostport | host:port combined (e.g. my-api:10000) |
You can also reference a specific env var from the private service using envVarKey instead of property.
Port Binding
Private services must bind to at least one port. If your process does not need to receive traffic, create a background worker instead.
- Bind to
0.0.0.0(not127.0.0.1orlocalhost) - The
PORTenv var defaults to10000; confirm current restrictions inreferences/private-networking.mdbefore choosing another port - For non-HTTP protocols (gRPC, TCP), configure your server on the desired port and tell consumers the
hostport
Blueprint Configuration
yamlservices: - type: pserv name: internal-api runtime: node region: oregon plan: starter buildCommand: npm ci && npm run build startCommand: npm start envVars: - key: DATABASE_URL fromDatabase: name: db property: connectionString
Microservices pattern (gateway + internal services)
yamlservices: - type: web name: gateway runtime: node plan: starter region: oregon buildCommand: npm ci && npm run build startCommand: npm start envVars: - key: USER_SERVICE_URL fromService: name: user-service type: pserv property: hostport - key: BILLING_SERVICE_URL fromService: name: billing-service type: pserv property: hostport - type: pserv name: user-service runtime: node plan: starter region: oregon buildCommand: npm ci startCommand: node server.js envVars: - key: DATABASE_URL fromDatabase: name: db property: connectionString - type: pserv name: billing-service runtime: python plan: starter region: oregon buildCommand: pip install -r requirements.txt startCommand: gunicorn billing:app envVars: - key: DATABASE_URL fromDatabase: name: db property: connectionString
References
| Document | Contents |
|---|---|
references/private-networking.md | Current private-network scope, addresses, ports, discovery, isolation, and troubleshooting |
references/patterns.md | Microservice topology, gRPC setup, and sidecar patterns |
references/persistent-disks.md | Service-attached disk constraints, configuration, sizing, and snapshots |
references/service-types.md | Service-type selection and execution models |
Related Skills
- render-web-services — Public HTTP services
- render-networking — Private network, DNS, service discovery
- render-background-workers — Services that don't receive traffic
- render-blueprints — Full
render.yamlschema,fromServicewiring - render-scaling — Compute plans and autoscaling for private services
Current documentation retrieval
Whenever this skill directs you to consult current Render documentation:
- Retrieve the linked Markdown document directly with an available URL-fetching tool or HTTP client, such as
curl. Do not substitute web-search summaries for the document. - Confirm that retrieval succeeded and returned the expected document, then read its contents. Saving a file or printing its path is not sufficient.
- If the request fails or your tool cannot read the Markdown response, open and read the linked HTML version instead.
- If neither version can be retrieved, disclose that the current reference is unavailable and follow any topic-specific fallback in the skill. Use bundled guidance only for stable constraints, and do not guess at changeable platform details.
When a task requires multiple references, apply this workflow to each one and distinguish the documents you verified from those that remain unavailable.


