logtail-lambda-extension

AWS Lambda Extension that uses the Lambda Telemetry API to forward logs to a Better Stack HTTP source.

Usage

In order to use the extension you must first build and deploy it into your AWS infrastructure:

$ git clone git@github.com:logtail/logtail-lambda-extension.git
$ cd logtail-lambda-extension
$ pnpm install
$ pnpm run build
$ aws lambda publish-layer-version \
--layer-name "logtail-lambda-extension" \
--zip-file "fileb://./dist/extension.zip" \
--compatible-runtimes nodejs22.x nodejs24.x \
--compatible-architectures x86_64 arm64

Once deployed set the SOURCE_TOKEN and INGESTING_HOST environment variables on your Lambda to the token and ingesting host from your Better Stack source settings (the ingesting host looks like s123456.lu-trq-1.betterstackdata.com), and add the layer to your Lambda function. On next invocation your Lambda logs should start appearing in Telemetry -> Live tail.

Environment Variables

Variable	Description	Default
SOURCE_TOKEN	Better Stack source token	required
INGESTING_HOST	Better Stack ingesting host	in.logs.betterstack.com
EXTENSION_NAME	Name of the lambda extension	logtail-lambda-extension
RECEIVER_ADDRESS	Address of the logs http receiver	sandbox
RECEIVER_PORT	Port of the logs http receiver	4243
MAX_ITEMS	Maximum number of events that can be buffered in memory	10000
MAX_BYTES	Maximum size in bytes of events that can be buffered	262144
TIMEOUT_MS	Maximum time (in milliseconds) that a batch is buffered	1000
AWS_LAMBDA_RUNTIME_API	HTTP base URI to the lambda runtime API	Provided by AWS Lambda environment
AWS_LAMBDA_RUNTIME_EXTENSION_API_VERSION	Lambda Extension API version date	2020-01-01
AWS_LAMBDA_RUNTIME_TELEMETRY_API_VERSION	Telemetry API version date	2022-07-01

SOURCE_TOKEN and INGESTING_HOST fall back to the legacy LOGTAIL_TOKEN and LOGTAIL_HTTP_API_URL (a full URL) variables when they are not set.

License

Unless explicitly stated otherwise all files in this repository are licensed under the MIT License. See LICENSE for more information.