Bref — Serverless PHP on AWS Lambda

Introduction

Bref provides custom AWS Lambda runtimes that let PHP applications run natively on Lambda. It packages PHP as a Lambda layer, handles request/response translation, and integrates with the Serverless Framework for deployment.

What Bref Does

• Provides PHP runtime layers for AWS Lambda supporting PHP 8.x
• Translates API Gateway and ALB events into PSR-7 or standard PHP requests
• Supports two modes: HTTP applications (web apps) and event-driven functions
• Integrates with Laravel, Symfony, and other PHP frameworks
• Manages deployment through Serverless Framework or AWS CDK

Architecture Overview

Bref publishes pre-compiled PHP binaries as Lambda layers. When a Lambda function is invoked, the Bref runtime bootstraps PHP, receives the event from the Lambda Runtime API, and passes it to your handler. For HTTP workloads, the php-fpm layer runs PHP-FPM as a child process, translating API Gateway events into FastCGI requests. For event-driven workloads, the function layer calls a PHP callable directly. Deployment artifacts are built by the Serverless Framework, which packages your code and references the correct Bref layer ARN.

Self-Hosting & Configuration

• Requires an AWS account with Lambda, API Gateway, and IAM permissions
• serverless.yml defines functions, runtime layers, and event triggers
• PHP extensions are included in the base layer; additional ones available as extra layers
• Environment variables are set in serverless.yml and accessible via getenv()
• Local development supported through serverless invoke local or Docker-based emulators

Key Features

• Pre-built Lambda layers with PHP-FPM and CLI runtimes for PHP 8.x
• Native support for Laravel (via Laravel Vapor alternative) and Symfony
• Console command execution on Lambda for cron jobs and queue workers
• Static asset handling through S3 with CloudFront integration
• Cold start optimization through smaller deployment packages and layer caching

Comparison with Similar Tools

• Laravel Vapor — Commercial, Laravel-only; Bref is open-source and framework-agnostic
• Vercel PHP — Limited PHP support; Bref provides full PHP-FPM runtime on Lambda
• AWS Lambda Web Adapter — Generic adapter; Bref is purpose-built for PHP with FPM integration
• Serverless Docker (Fargate) — Container-based, always running; Bref is event-driven with per-request billing

FAQ

Q: Which PHP versions does Bref support? A: Bref maintains layers for actively supported PHP versions, currently PHP 8.1 through 8.3.

Q: Can I use Bref with Laravel? A: Yes. Bref has dedicated documentation and packages for running Laravel on Lambda, including queue and scheduler support.

Q: How do I handle static assets? A: Static files are typically served from S3 behind CloudFront. Bref provides tooling to separate assets from the Lambda deployment package.

Q: What about cold starts? A: PHP-FPM cold starts on Lambda typically range from a few hundred milliseconds to about one second. Provisioned concurrency can eliminate them for latency-sensitive workloads.

Sources

• https://github.com/brefphp/bref
• https://bref.sh/docs