A family of modern, well-tested open source libraries for event sourcing and KurrentDB (formerly EventStoreDB) — from a low-level HTTP client to a batteries-included Symfony bundle.
About the name — Ouro was the friendly green dragon mascot of the original EventStore. It's not part of the official branding anymore, but we always had a soft spot for the little guy. Friends of Ouro is our nostalgic tip of the hat: same love for event sourcing, carried forward into the KurrentDB era.
The libraries that make up the family — append-only, just how we like it.
A convenience metapackage that bundles the core client with sensible default dependencies. The fastest way to go from composer require to writing events — most people should start here.
$ composer require friendsofouro/kurrentdb-phpThe flagship client for the KurrentDB HTTP API. Strict typing, stream management, optimistic concurrency, forward/backward iteration, batch operations and HTTP caching — all PSR-7/18 compliant.
$ composer require friendsofouro/kurrentdb-coreSeamless Symfony 7.3+ integration — service container wiring, configuration management and auto-wiring so KurrentDB feels native to your application.
$ composer require friendsofouro/kurrentdb-bundlePSR-18 interface contracts for sending many HTTP requests efficiently. Type-safe batch responses, exception aggregation and transformation utilities — the backbone of the core client's batched reads.
$ composer require friendsofouro/http-batch-contractA high-performance Guzzle implementation of the batch contract — concurrent request processing, built-in HTTP caching with filesystem and APCu adapters, plus retry logic.
$ composer require friendsofouro/http-batch-guzzleA ready-to-use Docker Compose setup for running KurrentDB locally. One command up, web UI on :2113, persistent storage — perfect for development and testing.
$ git clone git@github.com:FriendsOfOuro/kurrentdb-docker-example.gitSpin up KurrentDB with the Docker example, install the metapackage, and you're appending events to a stream.
# 1. Start KurrentDB locally
docker compose up -d
# 2. Install the metapackage (core client + sensible defaults)
composer require friendsofouro/kurrentdb-php<?php
use KurrentDB\EventStore;
use FriendsOfOuro\Http\Batch\Guzzle\GuzzleHttpClient;
use KurrentDB\WritableEvent;
use KurrentDB\ValueObjects\Identity\UUID;
use GuzzleHttp\Psr7\HttpFactory;
// Create the client
$httpFactory = new HttpFactory();
$httpClient = new GuzzleHttpClient();
$eventStore = new EventStore(
$httpFactory->createUri('http://admin:changeit@127.0.0.1:2113'),
$httpFactory, // UriFactory
$httpFactory, // RequestFactory
$httpClient,
);
// Write an event
$event = new WritableEvent(
new UUID(),
'user-registered',
['userId' => '123', 'email' => 'user@example.com'],
);
$version = $eventStore->writeToStream('user-123', $event);
// Read the stream back
foreach ($eventStore->forwardStreamFeedIterator('user-123') as $entry) {
echo 'Event: ' . $entry->getEvent()->getType() . PHP_EOL;
}
Modern PHP 8.4+ with value objects and strict types throughout — fewer runtime surprises.
Expected-version checks make safe, conflict-aware writes a first-class concern.
Comprehensive suites and CI across the family, so you can upgrade with confidence.
PHP 8.4 or higher · a KurrentDB server instance · Composer for package management.
Each repo has its own guidelines. Open issues, send PRs, or start a discussion — newcomers welcome.
Everything is released under the permissive MIT license. Build freely, commercial or otherwise.