Options

Configuration Options

Option	Type	Default	Description
specSource	{ type: "object"; spec: OpenAPISpec } | { type: "url"; spec: string } | { type: "file"; spec: string }	—	Provide your OpenAPI 3.x spec as an object, or point to it via URL or file path.
enable	boolean	true	Master switch: registers the mock interceptor globally. When false, interceptor is not registered.
mockByDefault	boolean	false	Controls default mocking behavior. When false, mock only when explicitly requested via headers or decorators.
strategyOrder	Array<"records" | "mediatype-examples" | "schema-examples" | "jsf" | "primitive" | "passthrough">	["mediatype-examples", "schema-examples", "jsf"]	Ordered list of strategies to attempt when generating responses.
defaultStatus	number	200	Default HTTP status code when not specified elsewhere.
seed	number | string	undefined	Seed for deterministic mock generation. Useful for snapshot testing.
delayMs	number | ((ctx: ExecutionContext) => number)	undefined	Simulated network latency in milliseconds.
jsf	object	(jsf defaults)	JSON Schema Faker configuration.
recording	object	undefined	Recording and replay configuration.
debug	boolean	false	Verbose logging for troubleshooting.

specSource

Type	Type	Typical use
"object"	OpenAPISpec	Static spec object.
"url"	string	Link to a centralized or externally hosted spec.
"file"	string	Local file path to a json/yaml file.

jsf

JSON Schema Faker configuration:

Option	Type	Default	Description
alwaysFakeOptionals	boolean	—	Include optional properties in generated data.
useDefaultValue	boolean	—	Use schema default values when present.
minItems	number	—	Minimum array size.
maxItems	number	—	Maximum array size.
formats	Record<string, () => any>	—	Custom format generators.
extend	(jsf: any) => void	—	Advanced configuration hook.

Example:

jsf: {
  alwaysFakeOptionals: true,
  useDefaultValue: true,
  minItems: 1,
  maxItems: 5,
  formats: {
    uuid: () => crypto.randomUUID(),
  },
  extend: (jsf) => {
    jsf.option("failOnInvalidTypes", false);
  },
}

recording

Recording and replay configuration for capturing real (non-mocked) responses. See Recording & Replay for detailed documentation.

Option	Type	Default	Description
dir	string	—	Directory to store/load recordings.
capture	boolean	false	Save real controller responses to disk.
matchBody	boolean	false	Include request body in replay key matching.
redact	Array<string>	—	Headers to redact from stored recordings.

Async Configuration

Use forRootAsync() for dependency injection:

MockModule.forRootAsync({
  imports: [ConfigModule],
  useFactory: (config: ConfigService) => ({
    specSource: { type: "object", spec: config.get("OPENAPI_SPEC") },
    enable: config.get("MOCK_ENABLED"),
    strategyOrder: config.get("MOCK_STRATEGY").split(","),
  }),
  inject: [ConfigService],
});