axyr/laravel-langfuse

Laravel Langfuse

Langfuse is an open-source observability platform for LLM applications. It gives you a dashboard to trace every LLM call, track token usage and costs, manage prompt versions, and evaluate output quality - all in one place. It's self-hostable or available as a managed cloud service.

This package connects your Laravel app to Langfuse. Send traces, generations, scores, and prompts with a clean, idiomatic API - or let the auto-instrumentation do it for you.

use Axyr\Langfuse\LangfuseFacade as Langfuse;

$trace = Langfuse::trace(new TraceBody(name: 'chat-request'));

$generation = $trace->generation(new GenerationBody(
    name: 'chat',
    model: 'gpt-4',
    input: [['role' => 'user', 'content' => 'Hello!']],
));

// After the LLM responds:
$generation->end(
    output: 'Hi there!',
    usage: new Usage(input: 12, output: 85, total: 97),
);

$trace->end(output: 'Hi there!');

Observations are batched and flushed automatically. Zero-code auto-instrumentation is available for Laravel AI, Prism, and Neuron AI.

Features

• Full observability - traces, spans, generations, events, and scores with automatic parent-child nesting
• Read & evaluate - query scores, observations, and metrics, and manage datasets, dataset items and experiments to build evaluation workflows (read API)
• Prompt management - fetch, cache, compile, create, and list prompts with stale-while-revalidate caching
• Auto-instrumentation - zero-code tracing for Prism, Laravel AI, and Neuron AI
• Automatic batching - completed observations queued and sent in batches over OTLP, with optional async dispatch via Laravel queues
• Production-ready - Octane compatible, graceful degradation, auto-end and auto-flush on shutdown, testing fakes

Installation

Requires PHP 8.2+ and Laravel 12 or 13. No PHP extensions beyond the core hash, random_bytes and json; zlib is only needed when you turn on LANGFUSE_COMPRESSION.

Langfuse compatibility. Since 0.4.0 the package writes traces over OpenTelemetry (OTLP) and reads back from the v2/v3 APIs:

Langfuse Cloud removes the deprecated ingestion and read endpoints on 2026-11-16. Upgrading to 0.4.0 before that date is required; see the upgrade guide.

composer require axyr/laravel-langfuse

Add your Langfuse credentials to .env:

LANGFUSE_PUBLIC_KEY=pk-lf-...
LANGFUSE_SECRET_KEY=sk-lf-...

Optionally publish the configuration file:

php artisan vendor:publish --tag=langfuse-config

Examples

Working example projects for each integration:

• Laravel AI + Langfuse - agents, tools, streaming, and scoring with the official Laravel AI SDK
• Prism + Langfuse - text, structured output, and streaming with Prism
• Neuron AI + Langfuse - agent workflows with Neuron AI

Documentation

Full documentation in the docs/ directory:

• Configuration - env vars, config publishing
• Tracing - traces, updating, nesting observations
• Generations - LLM generation tracking, usage and cost
• Spans and Events - non-LLM work, event logging
• Scores - numeric, boolean, categorical, text and correction scores
• Prompt Management - fetch, cache, compile, create
• Querying (read API) - read scores/observations, metrics, and the experiment workflow
• Integrations - Prism, Laravel AI, Neuron AI
• Middleware - request trace context
• Batching and Flushing - flush control, queued dispatch
• Testing - fakes and assertions
• Architecture - system diagram, Octane compatibility
• Troubleshooting - Langfuse v4 tracing, common issues
• Upgrading to 0.4 - what changed for Langfuse v4 and what you need to do

See the Changelog for release history.

Contributing

Contributions welcome. Open an issue first to discuss what you'd like to change.

composer test        # Run tests
composer pint        # Fix code style

License

MIT

Author

Built by Martijn van Nieuwenhoven - Laravel developer specializing in AI integrations and observability tooling.