OCaml SDK

The OCaml account client is in ocaml/auth.ml in mesgd-sdk. Use it to enroll an account, obtain a session, and manage public keys independently of the PKI layer. The examples use an existing account named alice; passwords and authenticator codes come from the application rather than literals in source.

Support status

The account adapter is available, but a built-in HTTPS transport is still pending. The transport argument in the examples is application code, not a missing SDK constructor.

Completeness position: 12 of 18. JWK storage, local PKI tests, and encrypt-to-key support; shared protocol coverage and native HTTPS remain pending. The language matrix explains the ranking criteria and comparable tiers. WSS readiness is listed separately; no SDK currently provides a complete, validated encrypted messaging workflow against this server.

Setup and transport

The account module depends on Yojson.Safe. The Dune library is named mesgd_auth, with wrapping disabled, so calls use the module name Auth. It is separate from the pki library and does not require that library's cryptographic dependencies.

Auth.transport is string -> string -> Yojson.Safe.t option -> string option -> int * Yojson.Safe.t. Supply an implementation backed by the application's verified HTTPS stack. No concrete HTTP transport is included.

A custom transport must serialize JSON, attach Authorization: Bearer TOKEN only when a token is supplied, verify the certificate and hostname, reject redirects, and use a finite timeout. Its origin is an HTTPS URL, such as https://mesgd.example.com, rather than a WebSocket URL.

Log in, read keys, and log out

Pass the current authenticator code as a six-digit string, preserving leading zeroes. This example reads the account's published keys and ends the session on its successful path. Applications that retain a session can keep the bearer until logout or expiry instead.

let read_keys (transport : Auth.transport) password otp =
  let session = Auth.login transport "alice" password otp in
  let token = Yojson.Safe.Util.(session |> member "access_token" |> to_string) in
  let keys = Auth.keys transport token in
  let _ = Auth.logout transport token in
  keys

Calls return Yojson.Safe.t. HTTP failures raise Auth.Http_error status; invalid inputs raise Invalid_argument. The PKI library has its own dependencies and includes encrypt_with and registration support, but is not part of the top-level shared protocol test target.

Enroll a new account

The following fragment uses an existing client or transport from the example above. Signup returns a pending enrollment. Display qr_png_base64 or otpauth_uri, let the person configure the authenticator, then collect a code to confirm it. These calls are separate application steps, with user interaction between them.

let enrollment = Auth.signup transport "alice" "alice@example.com" password [] in
(* Display enrollment before collecting enrollment_otp. *)
let enrollment_token =
  Yojson.Safe.Util.(enrollment |> member "enrollment_token" |> to_string) in
let session = Auth.confirm transport "alice" enrollment_token enrollment_otp in
let recovery_codes = Yojson.Safe.Util.member "recovery_codes" session in
recovery_codes

Confirmation returns the first session and eight recovery codes. Display the recovery codes for separate safekeeping. A code accepted for confirmation cannot be reused for login or a key update; wait for a new authenticator step before another operation that consumes a code.

Account operations

A key update takes the session token, current password, a fresh authenticator code, and an array containing only public JWKs. An empty array clears the linked keys. A password reset takes the username, a saved recovery code, a new password, and a fresh authenticator code; success replaces the recovery codes and revokes existing sessions without returning a new session.

The shared authentication reference documents argument order, response fields, and transport behavior. Session refresh is available through the HTTP API but is not wrapped by these seven SDK operations.

Message connections

The OCaml ping/pong sample links a mesgd library that is not defined in the current SDK Dune project. The independent mesgd_auth library does not provide that WSS client.

Account login does not establish a message connection. The current server accepts JSON WebSocket frames and can authenticate an upgrade with a login session or an issued grant token. Login sessions carry identity without path restrictions; grants limit routing to assigned patterns. See WebSocket and Routing.

The encrypted registration handshake in the ping/pong samples is not implemented by the current mesgd listener. Treat those samples as experimental cryptographic examples, with compatibility limits described in Samples.

Validation

This account module is not included in the shared auth contract runner. Check it with the application's own toolchain and transport before deployment. The presence of source examples does not imply that live HTTPS or cross-language cryptographic behavior has been validated for this implementation. Languages lists the repository's current test coverage.