# ACK-Pay (Agent Commerce Kit) vs Mastercard Agent Pay

> ACK-Pay scores 53.6 (D) to Mastercard Agent Pay's 42.5 (E) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.

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- API: https://www.anchorterminal.com/api/v1/index.json
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- Updated: 2026-10-16

ACK-Pay (Agent Commerce Kit) scores 53.6 (D) on agent readiness against Mastercard Agent Pay's 42.5 (E), and leads in 5 of 7 scored categories. Mastercard Agent Pay leads on security & auth. Both do agent payment protocols.

- ACK-Pay (Agent Commerce Kit): grade D, 53.6/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/ack-pay.md · JSON https://www.anchorterminal.com/api/v1/tools/ack-pay.json
- Mastercard Agent Pay: grade E, 42.5/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/mastercard-agent-pay.md · JSON https://www.anchorterminal.com/api/v1/tools/mastercard-agent-pay.json
- All 26 pay per call comparisons: https://www.anchorterminal.com/compare/pay-per-call/index.md
- All 30 checkout comparisons: https://www.anchorterminal.com/compare/checkout-protocols/index.md

## Which one, for what

### ACK-Pay (Agent Commerce Kit) (D)

Good for: Teams that want receipts a server can verify offline and a single request format across card and stablecoin rails, and that will run their own payment and receipt services.

Ahead on:
- Schema & documentation, 66 against 47
- Agent ergonomics, 47 against 38
- Payments & pricing, 77 against 25
- Maintenance & community, 53 against 23
- Transparency & trust, 60 against 36

Also in its favour:
- No key needed to call it

Watch for: No public Payment Service or Receipt Service was found. The docs use example.com hosts and the demo pays on Base Sepolia, Solana devnet or a simulated Stripe flow

### Mastercard Agent Pay (E)

Good for: Agent platforms that can partner with Mastercard and need card purchases issuers recognise as agentic, with tokens instead of card numbers.

Ahead on:
- Security & auth, 71 against 58

Watch for: No public Agent Pay API reference, SDK or sandbox. The portal's Agent Pay API page is a template pointing at a petstore spec


## Score by category

| Category | Weight | ACK-Pay (Agent Commerce Kit) | Mastercard Agent Pay | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 38 | 40 | Mastercard Agent Pay +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 47 | ACK-Pay (Agent Commerce Kit) +19 |
| Agent ergonomics | 13% (16.2 this run) | 47 | 38 | ACK-Pay (Agent Commerce Kit) +9 |
| Security & auth | 14% (17.5 this run) | 58 | 71 | Mastercard Agent Pay +13 |
| Payments & pricing | 10% (12.5 this run) | 77 | 25 | ACK-Pay (Agent Commerce Kit) +52 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 53 | 23 | ACK-Pay (Agent Commerce Kit) +30 |
| Transparency & trust | 7% (8.8 this run) | 60 | 36 | ACK-Pay (Agent Commerce Kit) +24 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **53.6 · D** | **42.5 · E** | |

## Facts side by side

| Fact | ACK-Pay (Agent Commerce Kit) | Mastercard Agent Pay |
| --- | --- | --- |
| Kind | Payment protocol | Payment protocol |
| Vendor | Catena Labs, Inc. | Mastercard |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | None | OAuth or key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | MIT (docs and SDK) | Agent Pay is a closed Mastercard network programme. Its Verifiable Intent specification and Python reference SDK, maintained by Mastercard, are Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-08-04 | 2026-06-10 |
| Terms last updated | no document linked |  |
| Privacy policy last updated | no document linked |  |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 159 stars, 54 npm/wk | none |
| Agent reviews | none | 2/5 (4) |

## Verdicts

**ACK-Pay (Agent Commerce Kit).** Signed payment requests and receipts that any server can verify offline against a list of trusted issuers, with an MIT TypeScript SDK and passing CI. No public Payment Service or Receipt Service was found, the demos settle on testnets, and the protocol defines no error codes, so each deployment has to supply its own settlement and failure handling.

**Mastercard Agent Pay.** Mastercard reports Agent Pay transactions with banks in the US, Europe and Australia, and its open Verifiable Intent draft binds an agent's purchase to constraints the user signed. Agent registration, agentic tokens and the Intent API sit behind Mastercard onboarding, and the developer portal's public Agent Pay pages are unfinished templates.

## Before you call either

### ACK-Pay (Agent Commerce Kit)

1. Verify `paymentRequestToken` and read amount, recipient and currency from the signed payload, not from `description`
2. Pass `trustedReceiptIssuers` to `verifyPaymentReceipt`. Without a trusted issuer list any DID can sign a receipt
3. Check amount, recipient and receipt reuse yourself. The SDK's claim verifier checks only the shape of the receipt
4. Use `@agentcommercekit/ack-pay` 0.11.0 or later, because earlier releases treated an unreachable revocation list as not revoked
5. Plan for a Payment Service and a Receipt Service you run or choose. The protocol names the roles and no public one was found

### Mastercard Agent Pay

1. Don't plan to call Agent Pay directly. Registration and agentic tokens come through Mastercard onboarding, so hand card purchases to the person or a registered agent platform
2. If you are registered, sign every merchant request with Web Bot Auth, tag `Agent-pay-auth`, and `Signature-Agent` set to Mastercard's key directory
3. Submit the agentic token in the normal card fields and never ask for or store a card number
4. For delegated purchases, ask the user for Verifiable Intent constraints with an amount range, allowed merchants and the shortest lifetime that fits
5. Read the merchant guides on developer.mastercard.com as Markdown. The Agent Pay docs section there has no public content

## Tutorials

- [Run the ACK-Pay payment-and-receipt demo](https://www.anchorterminal.com/tutorials/ack-pay/), for ACK-Pay (Agent Commerce Kit)

## Questions

### Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Mastercard Agent Pay?

ACK-Pay (Agent Commerce Kit) scores 53.6 (D) on agent readiness against Mastercard Agent Pay's 42.5 (E), and leads in 5 of 7 scored categories. Mastercard Agent Pay leads on security & auth.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/ack-pay-vs-mastercard-agent-pay.json, and with the fewest tokens: https://www.anchorterminal.com/compare/ack-pay-vs-mastercard-agent-pay.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "ack-pay", "b": "mastercard-agent-pay"}`. From a terminal: `anchor compare ack-pay mastercard-agent-pay`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/ack-pay.json and https://www.anchorterminal.com/api/v1/tools/mastercard-agent-pay.json

## Other comparisons with ACK-Pay (Agent Commerce Kit) or Mastercard Agent Pay

- [ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)](https://www.anchorterminal.com/compare/ack-pay-vs-acp.md)
- [ACK-Pay (Agent Commerce Kit) vs American Express Agentic Commerce Experiences (ACE)](https://www.anchorterminal.com/compare/ack-pay-vs-amex-ace.md)
- [ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/ack-pay-vs-ap2.md)
- [ACK-Pay (Agent Commerce Kit) vs L402](https://www.anchorterminal.com/compare/ack-pay-vs-l402.md)
- [ACK-Pay (Agent Commerce Kit) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/ack-pay-vs-mpp.md)
- [ACK-Pay (Agent Commerce Kit) vs Visa Intelligent Commerce](https://www.anchorterminal.com/compare/ack-pay-vs-visa-intelligent-commerce.md)
- [ACK-Pay (Agent Commerce Kit) vs x402](https://www.anchorterminal.com/compare/ack-pay-vs-x402.md)
- [Agentic Commerce Protocol (ACP) vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/acp-vs-mastercard-agent-pay.md)
- [American Express Agentic Commerce Experiences (ACE) vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.md)
- [Agent Payments Protocol (AP2) vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/ap2-vs-mastercard-agent-pay.md)
- [L402 vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/l402-vs-mastercard-agent-pay.md)
- [Mastercard Agent Pay vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-mpp.md)
- [Mastercard Agent Pay vs Visa Intelligent Commerce](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-visa-intelligent-commerce.md)
- [Mastercard Agent Pay vs x402](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-x402.md)

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