OpenConnector Features

OpenConnector is an API gateway and integration hub for Nextcloud. It brings enterprise service bus (ESB) capabilities natively into Nextcloud — define external API connections, expose your own endpoints, transform data with flexible mappings, and keep systems synchronized through scheduled or event-driven flows.

Feature Index

Feature	Description	Status
Sources	External API connections with multi-protocol authentication	Implemented
Endpoints	Expose reverse-proxy API paths with rule-based logic	Implemented
Mappings	Twig-powered data transformation between schemas	Implemented
Synchronizations	Scheduled and event-driven source-to-target sync	Implemented
Rules	Authentication, file handling, locking, and audit trail rules	Implemented
Jobs	Cron-based scheduled task execution	Implemented
Events & Webhooks	CloudEvents emission, subscription, and consumer processing	Implemented
Logging & Monitoring	Call logs, sync logs, and Prometheus metrics	Implemented
Configuration Management	Import/export, configuration groups, slug-based references	Implemented
StUF Adapter	REST/ZGW to StUF-BG/ZKN SOAP translation	Partial
Prometheus Metrics	Prometheus exposition format metrics + health endpoint	Implemented
DSO / Omgevingsloket Adapter	DSO-LV STAM koppelvlak integration	Implemented
iBabs & NotuBiz Connector	RIS integration for bestuurlijke besluitvorming	Implemented

Architecture Overview

External Systems                OpenConnector                     Targets
─────────────────    ───────────────────────────────────    ──────────────────
REST APIs         →  Sources → CallService → Mappings   →  OpenRegister
SOAP Services     →  Endpoints (reverse proxy)           →  External REST APIs
Webhooks          →  Consumers → EventService            →  Other Sources
Cron              →  Jobs → SynchronizationService       →  Register/Schema

Core Concepts

Sources

A Source is a configured connection to an external system. It stores the base URL, authentication method, headers, certificates, and request defaults. Sources are reused across endpoints, synchronizations, and jobs.

Endpoints

An Endpoint is a path exposed by OpenConnector that acts as a reverse proxy, OpenRegister gateway, or rule-execution surface. Endpoints have HTTP methods, target configuration, and an ordered list of Rules.

Mappings

A Mapping defines a field-level transformation between source and target schemas. It uses direct assignments, Twig template expressions, dot-notation paths, and JSON Logic conditions to reshape data structures.

Synchronizations

A Synchronization defines a full data flow: which Source to read from, which Mapping to apply, and which target (OpenRegister schema or another Source) to write to. The sync engine handles pagination, hash-based change detection, and per-object contract tracking.

Rules

A Rule adds logic to an endpoint. Rules enforce authentication, trigger synchronizations, handle file uploads/downloads, control resource locking, expose audit trails, and can be conditionally applied via JSON Logic.

Jobs

A Job schedules a synchronization or other task on a cron expression. Execution history is stored in job logs.

Events and Consumers

OpenConnector emits and consumes CloudEvents. Consumers are configured handlers that process incoming webhook payloads. EventSubscriptions subscribe to specific event types and route them to handlers.

Standards Compliance

Standard	Role
REST-API Design Rules (Logius)	API design for exposed endpoints
OpenAPI 3.0	Configuration import/export format
NL GOV CloudEvents	Event emission and consumption
Digikoppeling	PKIoverheid mTLS for government connections
StUF-BG 3.10 / StUF-ZKN 3.10	Legacy SOAP adapter (partial)
GEMMA Gemeentelijke servicebuscomponent	Primary architectural role
GEMMA Notificatierouteringcomponent	CloudEvents routing role

Data Model

Entity	Purpose
Source	External API connection configuration
Endpoint	Exposed reverse-proxy route
Mapping	Field-level transformation definition
Synchronization	Source-to-target sync flow definition
SynchronizationContract	Per-object sync state (origin ID, target ID, hash)
Rule	Endpoint logic (auth, file, lock, audit)
Job	Scheduled task with cron expression
Consumer	Incoming webhook/event handler
Event	CloudEvent definition
EventSubscription	Event listener with handler config
CallLog	HTTP request/response audit log
SynchronizationLog	Per-sync run result log