Docs · Operations

Managing nodes

Add, delete, and re-reference nodes at runtime. The service set is in the client by default — but most servers do not implement it. Catch ServiceUnsupportedException first, succeed second.

The OPC UA NodeManagement service set lets a client create and destroy nodes and references at runtime. The library exposes four methods on the client surface:

Method	What it does
`addNodes()`	Create one or more nodes under a parent
`deleteNodes()`	Remove existing nodes
`addReferences()`	Wire arbitrary references between nodes
`deleteReferences()`	Remove references

These are the only OPC UA mutation primitives. There is no MoveNode, no RenameNode — composing add + delete is the path.

Server support

NodeManagement is optional in the OPC UA spec. Many production servers (especially PLC-embedded ones) do not implement it. When that is the case, the very first call to any of the four methods raises:

php capability detection

use PhpOpcua\Client\Exception\ServiceUnsupportedException;

try {
    $client->addNodes([/* … */]);
} catch (ServiceUnsupportedException $e) {
    // Server does not implement NodeManagement (BadServiceUnsupported 0x800B0000).
    // Fall back to whatever pattern your application uses for static address spaces.
}

ServiceUnsupportedException extends ServiceException, so callers that catch the parent class still match. The exception fires on the first unsupported call; subsequent calls behave identically — there is no in-client capability cache. Wrap the first attempt in a guard and remember the answer yourself if you call these methods often. See Recipes · Handling unsupported services.

Info

The library is tested against open62541 v1.4.8 (ci_server) for the NodeManagement integration suite — open62541 enables this service set by default. UA-.NETStandard, which powers most of the uanetstandard-test-suite servers, does not implement it. Plan your reference server accordingly.

addNodes

Creates one or more nodes. Each entry in $nodesToAdd describes a node by its class and parent reference:

php examples/add-variable.php

use PhpOpcua\Client\Types\BuiltinType;
use PhpOpcua\Client\Types\NodeClass;

$results = $client->addNodes([
    [
        'parentNodeId'     => 'i=85',                    // Objects folder
        'referenceTypeId'  => 'i=35',                    // Organizes
        'requestedNewNodeId' => 'ns=1;s=Counter',        // optional — server may assign
        'browseName'       => '1:Counter',
        'nodeClass'        => NodeClass::Variable,
        'attributes' => [
            'displayName' => 'Counter',
            'description' => 'Boot-counter incremented by AddNodes',
            'dataType'    => 'i=6',                      // Int32
            'value'       => 0,
            'valueRank'   => -1,                         // scalar
            'accessLevel' => 3,                          // CurrentRead | CurrentWrite
        ],
        'typeDefinition' => 'i=63',                      // BaseDataVariableType
    ],
]);

foreach ($results as $r) {
    if ($r->statusCode === 0) {
        echo "Created: " . $r->addedNodeId . "\n";
    } else {
        echo "Failed: " . dechex($r->statusCode) . "\n";
    }
}

AddNodesResult:

Field	Meaning
`statusCode`	Per-node result. `0` = `Good`.
`addedNodeId`	The NodeId the server assigned (matches `requestedNewNodeId` when accepted, otherwise server-chosen).

Supported node classes

All eight OPC UA node classes are supported. Class-specific attributes are encoded automatically as the appropriate ExtensionObject (ObjectAttributes, VariableAttributes, etc.):

`NodeClass`	Class-specific attributes (key fields)
`Object`	`eventNotifier`
`Variable`	`dataType`, `value`, `valueRank`, `arrayDimensions`, `accessLevel`, `userAccessLevel`, `minimumSamplingInterval`, `historizing`
`Method`	`executable`, `userExecutable`
`ObjectType`	`isAbstract`
`VariableType`	`dataType`, `valueRank`, `value`, `isAbstract`
`ReferenceType`	`isAbstract`, `symmetric`, `inverseName`
`DataType`	`isAbstract`
`View`	`containsNoLoops`, `eventNotifier`

Common attributes (displayName, description, writeMask, userWriteMask) apply to every class. Omitting an attribute lets the server pick its default.

deleteNodes

php delete with reference cleanup

$statuses = $client->deleteNodes([
    ['nodeId' => 'ns=1;s=Counter', 'deleteTargetReferences' => true],
]);

deleteTargetReferences: true removes references that point at the deleted node from elsewhere — keeps the address space consistent. false leaves dangling references and is rarely what you want.
The return is a parallel int[] of per-node status codes.

addReferences

php link two existing nodes

$client->addReferences([
    [
        'sourceNodeId'     => 'ns=1;s=Counter',
        'referenceTypeId'  => 'i=46',                      // HasProperty
        'targetNodeId'     => 'ns=1;s=Counter.Description',
        'isForward'        => true,
        'targetNodeClass'  => NodeClass::Variable,
    ],
]);

deleteReferences

php remove a reference

$client->deleteReferences([
    [
        'sourceNodeId'      => 'ns=1;s=Counter',
        'referenceTypeId'   => 'i=46',
        'targetNodeId'      => 'ns=1;s=Counter.Description',
        'isForward'         => true,
        'deleteBidirectional' => true,
    ],
]);

deleteBidirectional: true also removes the inverse reference on the target node — usually what you want.

Authorisation and audit

Every call runs in the session's authorisation context. A session authenticated as anonymous on a hardened server will see BadUserAccessDenied per item. The four operations are also commonly audited server-side — expect a paper trail.

Failure modes per item

StatusCode	Meaning
`BadParentNodeIdInvalid`	Parent does not exist
`BadReferenceTypeIdInvalid`	Reference type is unknown
`BadNodeIdExists`	`requestedNewNodeId` is taken
`BadBrowseNameInvalid`	BrowseName is not unique among siblings
`BadTypeDefinitionInvalid`	TypeDefinition is missing or wrong
`BadNodeAttributesInvalid`	Class-specific attributes are malformed
`BadUserAccessDenied`	Session is not authorised

Last updated · 2026-05-21

Edit on GitHub Report issue

← Previous

Client-side aggregates

Security overview