Haskell SDK

The Haskell account client is in haskell/MesgdAuth.hs 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: 17 of 18. Account adapter source; native HTTPS, account-runner coverage, and the PKI rewrite 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

Add MesgdAuth.hs to the application and depend on aeson, containers, and text. Enable OverloadedStrings when writing literal usernames, paths, or JSON field names as Text. The account adapter does not choose an HTTP package.

Transport is Text -> Text -> Maybe Value -> Maybe Text -> IO (Int, Value). The example receives a transport whose HTTPS origin, certificate validation, redirect policy, and timeout have already been configured.

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.

{-# LANGUAGE OverloadedStrings #-}
import qualified MesgdAuth as Auth
import Data.Aeson (Value)
import Data.Aeson.Types (parseMaybe, withObject, (.:))
import Data.Text (Text)

readKeys :: Auth.Transport -> Text -> Text -> IO Value
readKeys transport password otp = do
  session <- Auth.login transport "alice" password otp
  case parseMaybe (withObject "session" (.: "access_token")) session of
    Nothing -> fail "invalid session response"
    Just token -> do
      result <- Auth.keys transport token
      _ <- Auth.logout transport token
      pure result

Calls return JSON Value in IO. HTTP failures throw HttpError Int, and invalid input throws InvalidInput. The separate Haskell PKI library is still being rewritten; the auth module does not depend on it.

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.

enrollment <- Auth.signup transport "alice" "alice@example.com" password []
-- Display enrollment, then obtain enrollmentOTP and extract the token.
case parseMaybe (withObject "enrollment" (.: "enrollment_token")) enrollment of
  Nothing -> fail "invalid enrollment response"
  Just token -> do
    session <- Auth.confirm transport "alice" token enrollmentOTP
    pure session -- Includes recovery_codes for the application to display.

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

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.