Overview

PhpOpcua\SessionManager\Client\ManagedClient is the application- side companion to the session manager daemon. It implements OpcUaClientInterface — the same contract as the direct PhpOpcua\Client\Client — and forwards every call through the IPC channel to the daemon, which owns the actual OPC UA session.

For application code, the substitution is mechanical:

use PhpOpcua\SessionManager\Client\ManagedClient;
use PhpOpcua\Client\Types\NodeId;

$client = new ManagedClient('/tmp/opcua-session-manager.sock');
$client->connect('opc.tcp://plc.local:4840');

$value = $client->read(NodeId::numeric(0, 2261));

use PhpOpcua\Client\ClientBuilder;
use PhpOpcua\Client\Types\NodeId;

// Direct — no daemon, no session reuse across requests
$client = ClientBuilder::create()->connect('opc.tcp://plc.local:4840');

$value = $client->read(NodeId::numeric(0, 2261));

The two are interchangeable from a call-site perspective. The difference is operational — see Differences from the direct client.

Constructor

new ManagedClient(string \$socketPath = '/tmp/opcua-session-manager.sock', float \$timeout = 30.0, ?string \$authToken = null)

The constructor does not open a connection. Configure the builder-style setters first, then call connect().

Builder-style configuration

ManagedClient exposes the same configuration setters as the direct ClientBuilder — security, trust store, cache, logging, events, retry, batching, browse depth. Every setter returns $this for chaining:

use PhpOpcua\SessionManager\Client\ManagedClient;
use PhpOpcua\Client\Security\SecurityPolicy;
use PhpOpcua\Client\Security\SecurityMode;
use PhpOpcua\Client\TrustStore\TrustPolicy;

$client = (new ManagedClient(
    socketPath: '/var/run/opcua/sessions.sock',
    authToken:  getenv('OPCUA_AUTH_TOKEN'),
))
    ->setSecurityPolicy(SecurityPolicy::Basic256Sha256)
    ->setSecurityMode(SecurityMode::SignAndEncrypt)
    ->setClientCertificate('/etc/opcua/client.pem', '/etc/opcua/client.key')
    ->setUserCredentials('integrations', getenv('OPCUA_PASSWORD'))
    ->setTrustStorePath('/var/lib/opcua/trust')
    ->setTrustPolicy(TrustPolicy::FingerprintAndExpiry)
    ->setTimeout(10.0)
    ->setAutoRetry(3);

$client->connect('opc.tcp://plc.local:4840');

Configuration values travel to the daemon as part of the open IPC command — the daemon constructs the underlying Client with those values. Setting these after connect() does not affect the already-open session — that session was opened with the values present at connect() time. To change them, disconnect and reconnect with the new configuration (see Opening and closing).

Session reuse

When connect() runs, the daemon looks for an existing session with the same (endpointUrl, sanitized config) pair. On a match, the existing session is reused — no OPC UA handshake, no CreateSession. The reuse is what amortises the cost of OPC UA across PHP requests.

wasSessionReused() exposes the answer to the caller:

$client->connect('opc.tcp://plc.local:4840');

if ($client->wasSessionReused()) {
    // No handshake — the session was already open on the daemon.
} else {
    // Fresh session — first connect with this configuration.
}

echo $client->getSessionId();   // daemon-assigned session ID, opaque

See Session reuse for the keying rules.

Drop-in compatibility

ManagedClient implements OpcUaClientInterface, so it can be type-hinted wherever the direct client would be:

use PhpOpcua\Client\OpcUaClientInterface;

final class DeviceService
{
    public function __construct(
        private readonly OpcUaClientInterface $client,
    ) {}

    public function readSpeed(): float
    {
        return $this->client->read('ns=2;s=PLC/Speed')->getValue();
    }
}

// Production wiring — through the daemon
$service = new DeviceService(new ManagedClient('/tmp/opcua.sock'));

// Test wiring — against the mock
$service = new DeviceService(MockClient::create());

This is the architectural payoff. The same service class works against the direct client, the managed client, and the mock — because all three implement the same interface. See opcua-client — testing reference.

What ManagedClient adds

Three methods exist on ManagedClient that are not on OpcUaClientInterface:

getEventDispatcher() exists on the interface but does not reach the daemon's events from the client side — see Differences from the direct client.

What ManagedClient routes through IPC

Every public operation. The transport cost is bounded by the serialiser (TypeSerializer) plus the daemon's query / invoke dispatch — typically a few milliseconds per call on a Unix socket, dominated by the OPC UA round-trip itself.

For exotic typed arguments — third-party module DTOs, custom ExtensionObjects — the daemon needs a ParamDeserializerInterface to decode them on its side. See Extensibility · Custom param deserializer.