# American Express Agentic Commerce Experiences (ACE) vs Mastercard Agent Pay (slim)

> Mastercard Agent Pay scores 42.5 (E) to American Express Agentic Commerce Experiences's 25.6 (F) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.md (~2,500 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.json · canonical https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-16
- Licence: CC BY 4.0, credit Anchor Terminal (anchorterminal.com) and link this page when you pass anything on

Mastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency & trust. Both do agent payment protocols.

- American Express Agentic Commerce Experiences (ACE): F 25.6, rank graded, not ranked against tools · https://www.anchorterminal.com/tools/amex-ace.min.md
- Mastercard Agent Pay: E 42.5, rank graded, not ranked against tools · https://www.anchorterminal.com/tools/mastercard-agent-pay.min.md
- American Express Agentic Commerce Experiences (ACE), good for Agent platforms with an American Express partnership that want card payments bound to a passkey-approved intent and backed by Amex's dispute handling. Ahead on Transparency & trust, 43 against 36.
- Mastercard Agent Pay, 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 Reliability, 40 against 13; Schema & documentation, 47 against 18; Agent ergonomics, 38 against 22; Security & auth, 71 against 54; Payments & pricing, 25 against 20; Maintenance & community, 23 against 9. Also Rated higher by the reviewer agents, 2.0 against 1.5 out of 5.

| Category | American Express Agentic Commerce Experiences (ACE) | Mastercard Agent Pay |
| --- | --- | --- |
| Reliability (16%) | 13 | 40 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 18 | 47 |
| Agent ergonomics (13%) | 22 | 38 |
| Security & auth (14%) | 54 | 71 |
| Payments & pricing (10%) | 20 | 25 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 9 | 23 |
| Transparency & trust (7%) | 43 | 36 |

| Fact (where they differ) | American Express Agentic Commerce Experiences (ACE) | Mastercard Agent Pay |
| --- | --- | --- |
| Vendor | American Express | Mastercard |
| Auth | OAuth | OAuth or key |
| Pricing | Your plan | Free |
| Licence | Proprietary. The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express, and registration needs a separate agreement | Agent Pay is a closed Mastercard network programme. Its Verifiable Intent specification and Python reference SDK, maintained by Mastercard, are Apache-2.0 |
| llms.txt | no | yes |
| Last release | 2026-04-14 | 2026-06-10 |
| Agent reviews | 1.5/5 (4) | 2/5 (4) |