Protocols make agents fluent. PeakCommerce makes them transact.
The Agentic Commerce Protocol (ACP) and the Model Context Protocol (MCP) give AI agents a standard way to discover tools and run checkout. But a fluent agent still can't change a B2B subscription on its own. PeakCommerce is the billing-flexible execution layer that turns an ACP or MCP request into a real order, upgrade, add-on, or plan change across the systems you already run — or its own built-in ordering when you don't run a billing engine.
Protocol-fluent, billing-flexible. Speaks ACP and MCP on top of Zuora, Stripe, Maxio, Orb, or Metronome — or its own built-in ordering. No billing engine required.
How agents speak to commerce: ACP and MCP.
These are complementary, not competing. MCP is how an agent discovers and calls tools; ACP is the commerce-specific contract for running a transaction. The 2026-04-17 ACP spec even adds MCP as a transport — the industry is converging on both.
Agentic Commerce Protocol (ACP)
ACP is an open standard that defines how AI agents complete purchases on behalf of buyers — the commerce-specific contract for agent-driven transactions.
- Agentic checkout: create, update, and complete checkout sessions
- Cart & feed: browse catalogs and manage carts before checkout
- Delegate payment & authentication: pass secure tokens, act on a buyer's behalf via OAuth 2.0
- Orders & webhooks: track confirmation, fulfillment, and refunds
Model Context Protocol (MCP)
MCP is an open standard that connects AI models to external tools and data through a universal JSON-RPC interface — the way an agent discovers and calls what it's allowed to do.
- Tools: typed, callable actions an agent can invoke
- Resources & prompts: structured context an agent can read
- Two-way client/server connections with capability negotiation
- An authorization framework for HTTP-based transports
Where a protocol request becomes a real transaction.
B2B subscription changes are the hard case — proration, add-ons, entitlements, and approvals spread across billing, CRM, and finance systems. A protocol standardizes the ask; the execution layer does the work.
Speaks ACP or MCP.
An AI agent in ChatGPT, a copilot, or your own app expresses intent — "add 20 seats", "upgrade to Enterprise" — using the open protocol it already supports.
Protocol defines the request.
ACP frames the checkout session and MCP exposes the callable tools, with scoped authentication and a typed schema. The agent now has a standard way to ask. It still can't fulfill the request.
PeakCommerce runs the change.
PeakCommerce receives the protocol request and resolves it into a real subscription action — proration, entitlements, approvals, and audit included — then writes the change across billing, CRM, and entitlements at once.
Your stack stays the source of truth.
Zuora, Stripe, Maxio, Orb, or Metronome remains the ledger; Salesforce and NetSuite stay in sync. Nothing migrates — the execution layer keeps every system in lockstep.
One execution layer, any billing stack.
A standard way for agents to ask.
ACP and MCP standardize discovery, authentication, and the shape of an agent request. They are intentionally billing-neutral — they describe the conversation, not how your subscription, proration, and entitlements actually change.
Execution on the stack you already run.
PeakCommerce is billing-flexible: native adapters for Zuora, Stripe, Maxio, Orb, and Metronome mean the same protocol request executes against the billing platform you have today — or through built-in ordering and direct payment-gateway connections if you don't run one. Become protocol-ready with or without a billing engine.
ACP, MCP, and the execution layer, answered.
What is the Agentic Commerce Protocol (ACP)?
ACP is an open standard, maintained by OpenAI and Stripe, that defines how AI agents complete purchases on behalf of buyers. It specifies composable building blocks — agentic checkout sessions, cart and product feeds, delegated payment and authentication, and orders and webhooks — so an agent can transact with a business using a consistent contract instead of a custom integration per merchant.
What is the Model Context Protocol (MCP)?
MCP is an open standard, introduced by Anthropic, that connects AI models to external tools and data through a universal JSON-RPC interface. An MCP server exposes typed tools, resources, and prompts; an MCP client (the agent) discovers and calls them with capability negotiation and an authorization framework. It is how an agent finds out what actions it is allowed to take and invokes them.
How do ACP and MCP work together?
They are complementary. MCP is the general transport for an agent to discover and call tools; ACP is the commerce-specific contract for running a transaction. The 2026-04-17 ACP specification adds MCP as a supported transport, so an agent can use MCP to reach an ACP-compliant commerce endpoint. PeakCommerce speaks both, so you don't have to bet on one.
Why isn't a protocol enough to run B2B subscription commerce?
A protocol standardizes the request, not the work behind it. B2B subscription changes involve proration, add-ons, entitlements, approvals, and revenue recognition spread across billing, CRM, and finance systems. A protocol-fluent agent can ask for an upgrade, but something has to execute it correctly across all of those systems. That execution layer is what PeakCommerce provides.
Does PeakCommerce support ACP and MCP?
Yes. PeakCommerce is the execution layer behind the protocols: it receives ACP and MCP requests and resolves them into real subscription transactions — upgrades, add-ons, plan changes, saves — with scoped agent authentication, the same pricing guardrails your team uses, and a full audit trail. Agents transact against the identical contract a human would.
Do I have to change my billing system to adopt ACP or MCP?
No — and you don't even need a billing engine. PeakCommerce is billing-flexible: it runs as a commerce layer on top of your existing stack with native adapters for Zuora, Stripe, Maxio, Orb, and Metronome, or it transacts on its own through built-in ordering and direct payment-gateway connections. If you run a billing platform it stays the system of record and PeakCommerce keeps everything in sync; if you don't, PeakCommerce handles the order itself. Either way you become protocol-ready without a billing migration.
See customer intent become revenue — instantly.
A real order, upgrade, or save — executed with your billing system or our built-in ordering — in a working demo.