Agentic Commerce
Agentic commerce is a purchase completed by an AI agent on a buyer's behalf, inside a conversation - no checkout page, no redirect, no hosted card form. VantagePay implements the Agentic Commerce Protocol (ACP) so an assistant such as ChatGPT or Claude can browse your catalogue, build a basket, take the buyer's card, and settle the payment through your merchant account.
A complete purchase looks like this from the buyer's side:
"Buy me GHS 20 of MTN airtime for 024 123 4567."
The agent resolves the product, collects the mobile number, authorises the card, submits the payment, and reports the confirmation number - in one exchange.
Two ways to integrate
| MCP Server | REST API | |
|---|---|---|
| Who calls it | An AI agent you do not control | Code you write |
| Use when | You want ChatGPT, Claude or another assistant to transact against your catalogue | You are building your own agent, storefront or orchestration layer |
| Transport | MCP Streamable HTTP at /mcp | JSON over HTTPS |
| Sequencing | Encoded in the tool descriptions - the agent is told what to call next | You own it |
| Buyer copy | Supplied by the server in each tool response | You write it |
| Setup effort | Paste a URL and a token into a connector | Normal API integration |
Both paths run the same pipeline underneath: the same sessions, the same delegated-payment tokens, the same settlement. Pick the surface that matches who is driving the purchase.
Start with the MCP server
If your goal is "our products should be buyable from ChatGPT", the MCP Server guide gets you to a working purchase in minutes - there is no code to write, only a connector to configure.
How a purchase works
Every agentic purchase follows the same six steps, whichever surface you use:
- Discover - find the product, its price, and any buyer details it requires.
- Open a checkout session - a priced basket with a 30-minute lifetime.
- Collect required product details - a mobile number, meter number, account number, network.
- Delegate payment - exchange the card for a single-use token bound to one session, one merchant, one currency and one maximum amount.
- Complete - redeem the token and queue the payment.
- Poll for the outcome - the payment settles asynchronously; the purchase is not done until it reports
completed.
Concepts worth knowing before you start
Checkout session. A priced basket plus its status. Created with a currency and line items, mutated by replacing the whole basket, and terminal once completed, cancelled or escalated. Sessions expire after 30 minutes by default.
Delegated payment token. Card details are exchanged for an opaque vt_… token constrained by an allowance: one checkout session, one merchant, one currency, a maximum amount, and a 15-minute window. The token is single use and is deleted the moment it is redeemed, so an agent never holds a reusable payment credential.
Minor units everywhere. Every amount in every request is expressed in the smallest currency unit. GHS 20.00 is 2000; ZAR 199.99 is 19999. This is the most common source of integration bugs.
Product fields. African payment products usually need more than a price - airtime needs a mobile number, a bill needs an account or meter number. Each product declares its required fields, and a checkout cannot complete until every required value has been supplied.
Asynchronous completion. Completing a checkout queues a payment; it does not settle it. The confirmation number returned is the transaction batch reference, which you can inspect through payment status like any other VantagePay payment.
No 3-D Secure step-up. Agentic card payments skip the step-up challenge and the buyer confirmation screen - that is what makes an in-conversation purchase possible, and it changes where liability sits. Review your card-scheme obligations before going live.
Prepare your catalogue
Agents can only sell what your catalogue describes well. Before testing:
- Give every product a clear name and description - this is the text the agent reasons over and reads out to the buyer.
- Set a category so free-text searches match.
- Declare required fields with human-readable labels and, where possible, a validation regex or a fixed list of allowed values. The agent uses the label to ask the buyer and the validation to check the answer before submitting.
- Deactivate products you do not want sold conversationally - only active products are returned.
Manage products through the Products API.
Next steps
- MCP Server - connect ChatGPT, Claude, Claude Code or any MCP client, with a full tool reference and a sandbox walkthrough.
- ACP REST API - endpoint-level reference for checkout sessions, delegated payments and the ACP product feed.
- Authentication - obtain and refresh the access token both surfaces require.