VB.NET Polymarket API Module (WinForms, .NET Framework 4.8)

I’m looking for a self-contained VB.NET module that communicates directly with the Polymarket API so I can place, cancel, and track Yes/No orders without jumping between tools.
This should integrate easily into an existing WinForms VB.NET Framework 4.8 application.

Note: I already have working authentication code (API key + signing), but it currently fails when trying to buy/sell. If you can diagnose and fix that while building the module, that’s a major plus.

Core Requirements

Target: .NET Framework 4.8, compatible with WinForms (no .NET Core dependencies).

Clean async wrapper around Polymarket REST endpoints using Task-based VB.NET methods.

Public API surface (strongly typed, no raw JSON):

PlaceOrder()

CancelOrder()

GetOrderStatus()
Each should accept/return strongly typed models (orders, IDs, enums, and errors).

Concurrency: Must support multiple open orders concurrently (thread-safe, Task-based or queue-based).

Resilience: Built-in error and rate-limit handling with retry/backoff and clear exception messages.

Wallet Support:
• Must work with both native Polymarket wallets and regular EOA (Metamask-style) wallets.
• I can provide a test wallet for sandbox testing.

Deterministic matching: Returned IDs and statuses should map cleanly to outbound requests for verification against the Polymarket dashboard.

Deliverables

Compilable VB.NET class or DLL targeting .NET Framework 4.8, ready to drop into an existing WinForms/WPF project.

Simple console demo that connects to Polymarket’s testnet or sandbox, places a Yes/No order, cancels it, and fetches the status.

Documentation: XML or markdown comments for all public members plus a short setup guide covering:

API keys and environment variables

Wallet configuration (Polymarket + EOA)

Signing/auth flow

Any NuGet dependencies compatible with .NET 4.8

(Optional but preferred) Fix my current buy/sell flow that fails despite working authentication.

Testing & Acceptance

I’ll test by firing simultaneous orders and comparing returned IDs and statuses with the Polymarket dashboard.

Must handle parallel requests without blocking or collisions.

Clear logs for network, auth, and rate-limit issues.

Nice to Have
Experience with crypto or prediction market APIs, EIP-712 signing, or exchange-style order flows.
Simple rate-limit handling (token bucket or exponential backoff).
Clean, dependency-light VB.NET code.

If you have experience with Polymarket, Metamask-style wallets, or EVM signing, please mention that.
I can share my test wallet and existing authentication code for integration and verification.