Inside Muse's Purchase Protocol, and What Your MCP Server Must Expose
11/9/2026
Jules Kovac
Business Analyst, Founder
Meta's Muse can find a jacket, fill the address, compute the tax and still be unable to pay, because Meta gives it permission to spend from outside the model, bound to one order and one clock. That gate is the consumer half of the story. The merchant half is a contract most teams get backwards: cart first, checkout last, and five MCP surfaces instead of three. This article walks both halves once, with the exact statuses, tiers and idempotency rules Shopify now documents.

