awskit

Libraries

awskit

The entrypoint is Awskit.

Core modules:

• Awskit.Credentials — opaque AWS access keys and session tokens
• Awskit.Region — AWS region names with result/exn constructors
• Awskit.Endpoint — scheme, host, port, authority, and URL helpers
• Awskit.Body — runtime-neutral upload and payload-hash metadata
• Awskit.Request — body-free HTTP request metadata
• Awskit.Response — body-free HTTP response metadata and header helpers
• Awskit.Error — structured errors and retry classification
• Awskit.Retry — shared retry policy used by service packages
• Awskit.Signing — pure AWS Signature Version 4 signing
• Awskit.Runtime.S — runtime abstraction used by service packages

awskit-eio

Awskit_eio is the direct-style Eio runtime adapter. Its monad type is type 'a t = 'a. Response bodies are scoped to with_response and Runtime.Response_body.with_reader.

awskit-lwt

Awskit_lwt is a generic Lwt runtime functor over Cohttp_lwt.S.Client. Use it for custom Lwt HTTP backends.

awskit-lwt-unix

Awskit_lwt_unix is the ready-to-use Lwt + Unix runtime adapter. It can load credentials from standard AWS environment variables, shared AWS profile files, ECS/container metadata, or EC2 instance metadata, and region from standard AWS environment variables when arguments are omitted.

awskit-unix

Awskit_unix contains Unix-specific credential and region sources. It does not perform HTTP calls.

Minimal Signing Example

let credentials =
  Awskit.Credentials.create_exn
    ~access_key_id:"AKIAIOSFODNN7EXAMPLE"
    ~secret_access_key:"wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"
    ()
in
let region = Awskit.Region.of_string_exn "us-east-1" in
let payload_hash = Awskit.Body.Payload_hash.sha256_of_string "" in
Awskit.Signing.sign_request
  ~credentials
  ~region
  ~service:"s3"
  ~method_:`GET
  ~path:"/my-key"
  ~query:""
  ~headers:[ ("host", "my-bucket.s3.us-east-1.amazonaws.com") ]
  ~payload_hash
  ~now:Ptime.epoch

Signing is pure and testable without network access. Service packages sign requests automatically; use Awskit.Signing directly for custom AWS services or low-level tests.

Minimal Eio Runtime Example

Eio.Switch.run @@ fun sw ->
let region = Awskit.Region.of_string_exn "us-east-1" in
let conn =
  Awskit_eio.create
    ~env
    ~sw
    ~region
    ~credentials
    ()
in
ignore conn

Minimal Lwt Unix Runtime Example

let conn =
  Awskit_lwt_unix.create ()
  |> Result.get_ok
in
ignore conn

When omitted, awskit-lwt-unix reads:

AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEY
AWS_SESSION_TOKEN
AWS_REGION
AWS_DEFAULT_REGION

Service Packages

• awskit-s3 — AWS S3 object-storage client, presigning, and runtime-backed operations
• awskit-s3-sim — in-memory S3 implementation for tests

Guides

• Guides — credentials, regions, endpoints, signing, structured errors, streaming runtime bodies, and adapter selection