Internal Endpoints

LocalStack provides several internal endpoints for various local AWS services and LocalStack-specific features. These endpoints are not part of the official AWS API and are available in the /_localstack and /_aws paths. You can use curl or your favourite HTTP REST client to access endpoints.

You can start your LocalStack instance and go to http://localhost.localstack.cloud:4566/_localstack/swagger to browse the Swagger UI, visualize and interact with all the API’s resources implemented in LocalStack.

LocalStack endpoints

The API path for the LocalStack internal resources is /_localstack. Several endpoints are available under this path. For instance, /_localstack/health checks the available and running AWS services in LocalStack while /_localstack/diagnose (enable with the DEBUG=1 configuration variable), reports extensive and sensitive data from the LocalStack instance.

Tip

You can use the /_localstack/health endpoint to restart or kill the services. You can use curl or your HTTP REST client to access the endpoint:

curl -v --request POST --header "Content-Type: application/json"  --data '{"action":"restart"}' http://localhost.localstack.cloud:4566/_localstack/health
curl -v --request POST --header "Content-Type: application/json"  --data '{"action":"kill"}' http://localhost.localstack.cloud:4566/_localstack/health

AWS endpoints

The API path for the AWS internal resources is /_aws. These endpoints offer LocalStack-specific features in addition to the ones offered by the AWS services. For instance, /aws/services/sqs/messages conveniently access all messages within a SQS queue, without deleting them.

x-localstack response header

LocalStack adds an x-localstack HTTP header to every response served by its AWS gateway. The header value is the LocalStack version string (for example, 2026.3.1.dev65), so client tools can detect both that they are talking to LocalStack and which version is running in a single round-trip.

curl -s -i http://localhost.localstack.cloud:4566/_localstack/health | grep -i x-localstack
# x-localstack: 2026.3.1.dev65

Note

Before LocalStack v2026.04, the header value was the static string true. Starting with v2026.04, it returns the LocalStack version instead. Clients that only check for the presence of the header remain compatible.

The header is enabled by default and can be disabled by setting LOCALSTACK_RESPONSE_HEADER_ENABLED to 0.