Interoperability

Interoperability

The point of building on BabelQueue is that the queue you produce and consume in PHP is the same queue other languages use. The wire format is the canonical envelope; routing is by URN, never a PHP class name. This page shows a message crossing a language boundary in each direction.

PHP produces, another language consumes

Publish from PHP as usual:

use InitPHP\Queue\Producer\Producer;
use InitPHP\Queue\Transport\Redis\RedisTransport;

$producer = new Producer(new RedisTransport(new Predis\Client('tcp://127.0.0.1:6379')), 'orders');
$producer->send('urn:babel:orders:created', ['order_id' => 1042, 'amount' => 99.90]);

The bytes on the orders list are the canonical envelope:

{
  "job": "urn:babel:orders:created",
  "trace_id": "…",
  "data": { "order_id": 1042, "amount": 99.90 },
  "meta": { "id": "…", "queue": "orders", "lang": "php", "schema_version": 1, "created_at": 1749132727000 },
  "attempts": 0
}

A consumer in any BabelQueue SDK reserves from the same orders queue, matches on job == "urn:babel:orders:created", and reads data.order_id. No shared PHP type, no serialize(), no translation layer.

Another language produces, PHP consumes

Nothing changes on the PHP side — the worker decodes and routes by URN:

$handlers = (new HandlerMap())->register('urn:babel:orders:created', RecordOrder::class);
$worker   = new Worker($transport, new Dispatcher($handlers), new WorkerOptions());
$worker->run('orders');

Two cross-language details the runtime handles for you:

• The urn alias. Some SDKs emit the field as urn instead of job; the worker accepts both. A message produced with urn routes to your handler identically.
• Producer language. meta.lang (go, python, …) is available via $message->getMeta()['lang'] for logging, but never affects routing.

Trace propagation across services

trace_id is preserved unchanged across every hop and language. When a handler dispatches a downstream job, carry the incoming trace id forward so the whole chain shares one trace:

use BabelQueue\Contracts\InboundMessage;
use InitPHP\Queue\Contracts\Handler;
use InitPHP\Queue\Producer\Producer;

final class RecordOrder implements Handler
{
    public function __construct(private readonly Producer $producer) {}

    public function handle(InboundMessage $message): void
    {
        // ... record the order ...

        $this->producer->send(
            'urn:babel:billing:invoice.requested',
            ['order_id' => $message->getData()['order_id']],
            'billing',
            $message->getTraceId(),   // continue the same trace
        );
    }
}

A Go or Python service further down the chain sees the same trace_id, so a single distributed trace spans all of them.

Conformance

The runtime is tested against the SDK's cross-SDK conformance fixtures — the golden files every BabelQueue SDK must satisfy (order-created, the Go urn-alias, dead-lettered, a unicode-and-numbers round-trip, and the invalid cases). If those pass, a message produced by any conforming SDK is consumable here.

For the full cross-language standard, see babelqueue.com.