Requires

Declares required resource dependencies. The app will not start without them. Value is an array; each entry is a string (shorthand) or an object.

A string shorthand (requires: [postgres]) expands to [{ type: "postgres" }].

Field	Type	Required	Description
`name`	`string`	no	Resource name for expression references (defaults to `type`)
`type`	`string`	yes	Resource type (see Resource Property Vocabulary)
`version`	`string`	no	Version constraint using semver ranges (e.g. `>=15`, `^7.0`, `20.x`)
`config`	`map<string, any>`	no	Resource provisioning hints (platform-interpreted)
`set_env`	`map<string, string>`	no	Maps resource properties to app env vars using `$` expressions

requires:
  - type: postgres
    version: ">=15"
    set_env:
      DATABASE_URL: $url
      DB_HOST: $host
      DB_PASSWORD: $password

Resource naming

By default, a resource's name is its type. Expression references like $postgres.host use this name. When an app requires multiple instances of the same type, use the name field to distinguish them:

requires:
  - type: postgres
    name: primary-db
    set_env:
      PRIMARY_DB_URL: $url
  - type: postgres
    name: analytics-db
    set_env:
      ANALYTICS_DB_URL: $url

References use the name: $primary-db.host, $analytics-db.host. Without name, two resources of the same type would be ambiguous.

Version constraints

The version field uses semver range syntax (as defined by node-semver):

Syntax	Meaning
`>=15`	Version 15 or higher
`^7.0`	Compatible with 7.x (>=7.0.0, <8.0.0)
`~2.1.0`	Approximately 2.1.x (>=2.1.0, <2.2.0)
`20.x`	Any 20.x version
`15.2.0`	Exact version

Resource configuration

The config map passes provisioning hints to the platform. Keys and semantics are resource-type-specific:

requires:
  - type: postgres
    version: ">=15"
    config:
      extensions: [pgvector, postgis]
      shared_buffers: 256MB
  - type: redis
    config:
      maxmemory: 256mb
      maxmemory-policy: allkeys-lru

The platform interprets these hints when provisioning the resource. Unknown keys are ignored by platforms that don't support them.

Expression wiring

Values in set_env use the expression syntax. Inside a requires or supports block, bare $prop references resolve against the enclosing resource's property vocabulary.

Real-world examples: See how Ghost, Metabase, and Miniflux declare their database requirements. Browse all apps →