Proposal for a C# SDK for the Agentic Commerce Protocol (ACP)

[AhmadAlMunajjed]

Proposal: Support for Agentic Commerce Protocol (ACP) in C# SDK

Overview

The Agentic Commerce Protocol (ACP) is an open standard co-developed by OpenAI and Stripe, designed to enable AI agents to interact with merchants, payment processors, and fulfillment systems in a secure and standardized way.

Currently, this C# SDK supports the Model Context Protocol (MCP), which is essential for AI context and tool integration. Extending support to ACP would allow AI agents built on .NET to handle commerce transactions seamlessly, including product discovery, checkout, and delegated payments.

Motivation

• Unified AI Integration: Developers using this SDK could leverage the same framework for both context (MCP) and commerce (ACP).
• Enterprise Readiness: .NET/C# is widely used in enterprise environments. Supporting ACP would allow organizations to adopt AI-powered commerce workflows natively.
• Open Standard Adoption: Microsoft’s involvement would help accelerate ACP adoption in the .NET ecosystem and maintain alignment with open standards.

Proposed Features

• Product Feed API: Enable AI agents to access structured merchant catalogs.
• Agentic Checkout: Support creation and management of checkout sessions via the SDK.
• Delegated Payment Tokens: Provide secure handling of payment credentials.
• Integration Examples: Include sample code demonstrating how to integrate ACP with existing .NET applications.

References

• Agentic Commerce Protocol Overview
• ACP Specification GitHub

Request

I would like to propose that the C# SDK be extended to support ACP, either as part of the core SDK or as a companion library. This would enable developers to build AI agents capable of handling both context and commerce in a .NET environment.

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Thank you for considering this proposal. I’m happy to contribute or help test ACP-related functionality if needed.

[stephentoub]

What does ACP have to do with MCP? ie why would the MCP SDK be the library to implement ACP rather than it being a separate thing?

[AhmadAlMunajjed]

Thanks for your reply! I realized that ACP could optionally integrate with MCP but doesn’t have to.
ACP is a different protocol—distinct from MCP—and makes sense as a separate SDK.
It would be appreciated if you could guide me on the right place to share my ACP proposal.

[eiriktsarpalis]

It would be appreciated if you could guide me on the right place to share my ACP proposal.

Have you tried filing an issue with the ACP repo itself? If there's an organization willing to sponsor a C# SDK it's more likely that they would be found there.