Ready-to-use Lwt + Unix runtime adapter for Awskit.
The public entrypoint is Awskit_lwt_unix. This package wires the generic Lwt runtime to Cohttp Lwt Unix and the standard Unix credential and region sources.
Use it at the application edge when a Lwt service client should load AWS configuration from environment variables, shared profile files, or supported metadata sources.
Awskit_lwt_unix.create accepts explicit region and credentials. When either is omitted, the adapter reads the standard Unix sources: static environment credentials, shared AWS profile files, ECS/container credentials, and EC2 instance metadata credentials for credentials, plus AWS_REGION then AWS_DEFAULT_REGION for the region.
The credential provider chain stops on invalid configured sources and refreshes metadata credentials before expiration. IMDSv2 is preferred for EC2 metadata; tokenless IMDSv1 fallback is controlled by the imdsv1_fallback argument and AWS_EC2_METADATA_V1_DISABLED.
The runtime preserves Lwt cancellation and callback exceptions as native Lwt control flow. Response bodies are scoped to the operation callback; after a successful consumer returns, the runtime drains up to max_response_drain_bytes for connection reuse. Consumer errors take precedence over cleanup failures.
Use Awskit_lwt.Make from awskit-lwt when an application needs a custom Cohttp Lwt backend instead of the ready Unix client.