Configuration and extensions

simulation() accepts an initialState fixture and optional configuration:

• apiUrl changes the mounted REST API root; it defaults to /.
• apiSchema selects a bundled or custom OpenAPI schema.
• extend.extendStore adds store slices, actions, or selectors.
• extend.openapiHandlers adds or overrides OpenAPI operation handlers.
• extend.extendRouter adds Express routes for a particular test harness.

See the API reference for argument details and supported operations, and the architecture guide for the responsibilities of each extension hook. Unlisted API operations should be treated as unsupported until documented.

The sections below explain identity, fixture construction, shared writes, and request actors. Contributor setup and validation commands are in the developers guide; the documentation contents links the remaining references.