REST API & Extension
Automatically generated endpoints and a Java rule engine for custom business logic.
Nuclos exposes a consistent REST interface for every modelled business object. Custom logic beyond configuration is implemented as server-side Java rules.
The technical reference lives in the Nuclos wiki under Development and Configuration.
REST API
Base path /rest. CRUD over business objects, generated from the data model.
- Endpoints are generated automatically from the data model, with no manual upkeep.
- Consistent schema: GET, POST, PUT, DELETE for every modelled object.
- Lists and details via /rest/bos/{boMetaId} and /rest/bos/{boMetaId}/{boId}.
- Subforms via /rest/bos/{boMetaId}/{boId}/subBos/{refAttrId}.
- Authentication via session or token. Details and parameters are in the wiki.
GET /rest/bos/{boMetaId}/{boId}
Cookie: JSESSIONID=<session>
→ 200 OK
{
"boId": "4711",
"boMetaId": "example_rest_Order",
"attributes": {
"example_rest_Order_orderNumber": "A-10042",
"example_rest_Order_customer": { "id": "200", "name": "Muster GmbH" }
}
} Calling external REST services from rules
Register an OpenAPI spec, generate a Java client, call it from rule code.
Under Administration → REST APIs you register an OpenAPI specification. Nuclos generates Java client classes under /data/codegenerator/src-conf-rest/.
An adapter class (for example NuclosRESTAdapter) initialises the endpoint so you can call the generated API methods from rule code.
Server-side rule engine
Bind Java rules to events: insert, update, delete, state change, custom action.
When business logic cannot be expressed with low-code mechanisms alone, implement server-side rules as Java classes. Each rule implements a typed interface and is assigned to an event in the Server Rule Manager via drag and drop.
-
Insert (InsertRule / InsertFinalRule)
When a new record is created. Controllable before and after save.
-
Update (UpdateRule / UpdateFinalRule)
When existing records change, including validation and post-processing.
-
Delete (DeleteRule / DeleteFinalRule)
On delete, for example for dependent data or release checks.
-
State change (StateChangeRule / StateChangeFinalRule)
On a state-model transition, for example from Open to Released.
-
Custom action (CustomRule)
For explicitly triggered actions on a business object.
Supporting provider classes
- BusinessObjectProvider, QueryProvider, DatasourceProvider
- MailProvider, FileProvider, ReportProvider, PrintoutProvider
- GenerationProvider, ImportProvider, ParameterProvider, StatemodelProvider
Development in the IDE
You develop rule code as a Maven project. Nuclos provides a pom.xml under /data/codegenerator. Generated business-object classes and the API at api.nuclos.de are available in the IDE.
More topics in the Dev Portal
Technical entry points for architecture, integration, and operations.
Discuss interfaces and self-build?
We cover technical questions on REST, rules, or integration in an initial call.