---
title: OPC UA
slug: api-docs/opc-ua-reference
description: OPC UA endpoints for Litmus Edge: server config, session lifecycle, namespace browse, node CRUD, and subscription management. Reference with live execution on api.litmus.io.
docTags: 
createdAt: 2026-05-11T22:08:04.430Z
---

# OPC UA (LE)

27 endpoints. GraphQL on `/opcua/v2`. Manages the **embedded OPC UA server** that re-exposes DeviceHub tags to downstream OPC UA clients.

:::BlockQuote
**Run these endpoints:** open the [OPC UA folder on api.litmus.io](https://api.litmus.io/view/2s9Y5R1RvG#6bb95043-4e3d-458e-8088-9fb008a8ead3).
:::

:::BlockQuote
This is **distinct from the OPC UA Advanced client driver** (used to read from external OPC UA servers). The client driver lives under DeviceHub. The server lives here.
:::

## Sub-areas

| Folder      | Purpose                                                              |
| ----------- | -------------------------------------------------------------------- |
| Hierarchy   | Browse and edit the OPC UA address space the embedded server exposes |
| Management  | Service config, endpoints, certificates, users                       |
| Connections | Currently connected OPC UA clients                                   |

## Typical operations

### Hierarchy

| Operation                 | Purpose                                           |
| ------------------------- | ------------------------------------------------- |
| `GetNodeRoot`             | Read the root of the namespace                    |
| `GetNodes(ParentID)`      | Children of a node                                |
| `CreateNode`              | Add a node (folder or variable)                   |
| `DeleteNode`              | Remove                                            |
| `ImportAllDHTags`         | Bulk-import every DeviceHub tag as an OPC UA node |
| `ImportSomeDeviceHubTags` | Selective import (by device or tag IDs)           |
| `ClearAllNodes`           | Wipe the address space                            |

### Management

| Operation                                 | Purpose                                           |
| ----------------------------------------- | ------------------------------------------------- |
| `GetServiceConfiguration`                 | Endpoint URL, security policies, anonymous toggle |
| `UpdateServiceConfiguration`              | Edit                                              |
| `StartOPCUAService`, `StopOPCUAService`   | Lifecycle                                         |
| `ListUsers`, `CreateUser`, `DeleteUser`   | Server users (for username/password auth)         |
| `GetCertificate`, `RegenerateCertificate` | Server cert                                       |

### Connections

| Operation          | Purpose                        |
| ------------------ | ------------------------------ |
| `ListConnections`  | Currently connected clients    |
| `DisconnectClient` | Force-disconnect by session ID |

See [Configure OPC UA Server workflow](#).