Merchant Payment Protocol (MPP)

MPP exposes merchant payment capabilities to agents.

Category: Commerce
Standard: Emerging; Off by default, turn on in settings

0%Top 100 adoption0 of 91 sites implement it 2/9OverviewSpeculativeSpecified, but little evidence anything uses it yet.

Who supports it

No agent or browser has announced support yet.

27 others: no evidence yet. See every agent and browser

What it checks

MPP describes what a merchant accepts and how an agent can pay, so the agent can settle a purchase without a person filling in a checkout form.

The extension requests /.well-known/mpp.json and /.well-known/merchant-payment-protocol, in that order, and passes on the first one that returns a non-empty JSON document.

Commerce protocols are new, and most sites have no reason to support them, so absence is N/A rather than a failure.

Results

Status	When
Pass	One of the paths returns a non-empty JSON document
N/A	Nothing was found

How to fix

If you sell to agents, publish an MPP descriptor at /.well-known/mpp.json advertising your payment capabilities. Serve it as JSON (Content-Type: application/json); the extension only confirms a JSON document is there and does not validate its contents.

These standards are still settling, so follow the protocol’s own documentation for what the descriptor should contain.

Support by agent and browser

Announced means the vendor’s own docs or announcement say so. Published is the date on the vendor’s own page, where it has one. Checked is the last time our weekly research found that page still saying so.

No agent or browser has announced anything about this yet.

No evidence yet27

ChatGPT
Claude
Gemini
Perplexity
Copilot
Meta AI
ChatGPT Atlas
Comet
Dia
Gemini in Chrome
Edge Copilot Mode
Claude Code
Cursor
Codex
GitHub Copilot
Windsurf
CCBot
Applebot
Amazonbot
Bytespider
Cohere
Mistral
DuckAssist
Chrome
Edge
Firefox
Safari

Names and marks belong to their owners and are used only to identify products. None of these vendors is affiliated with Sitebulb. Spotted something out of date? Send a correction.

Adoption on the top 100 sites

0 of 91 measured sites implement it

Scanned 23 Oct 2026 with the Sitebulb Labs extension, against the Tranco list (tranco-56Z8N). 9 sites couldn’t be measured (bot challenge or timeout) and are left out of the share.

9 Oct 2026 0% → 23 Oct 2026 0%

Overview

2/9

Speculative

Specified, but little evidence anything uses it yet.

How this rating is worked out2 of 9 points

Factor	Points	Why
Vendor support	0 / 3	0 vendors supporting, 0 partly or planned
Top-100 adoption	0 / 3	0% of measured sites
Spec maturity	2 / 3	Standards-track draft

8 or more points is Established, 5 to 7 is Gaining traction, 2 to 4 is Speculative and under 2 is Stalled. A feature is also Stalled when more vendors have said no than yes. Read the spec.

Community insights

No community insights for this feature yet.

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