Building from Source

AWS Lambda Web Adapter is written in Rust and based on the AWS Lambda Rust Runtime.

Prerequisites

• Rust toolchain
• cargo-lambda

Clone the Repository

git clone https://github.com/awslabs/aws-lambda-web-adapter.git
cd aws-lambda-web-adapter

Build with cargo-lambda

cargo-lambda handles cross-compilation for Lambda targets automatically — no need to install cross-compiler toolchains manually.

Build for x86_64:

cargo lambda build --release --extension --target x86_64-unknown-linux-musl

Build for arm64:

cargo lambda build --release --extension --target aarch64-unknown-linux-musl

The compiled extension is placed under target/lambda/extensions/.

Package as Docker Image

After building with cargo-lambda, you can package the binary into a minimal container:

# x86_64
printf 'FROM scratch\nADD target/lambda/extensions/. /\n' | docker build --platform=linux/amd64 -t aws-lambda-adapter:latest-x86_64 -f- .

# arm64
printf 'FROM scratch\nADD target/lambda/extensions/. /\n' | docker build --platform=linux/arm64 -t aws-lambda-adapter:latest-aarch64 -f- .

Or use the Makefile targets which combine both steps:

make build-image-x86
make build-image-arm64

Running Tests

cargo fmt -- --check
cargo clippy -- -Dwarnings
cargo nextest run