{"type":"firestarter.listing","listing":{"id":"lst_8TGcTpio","product_name":"Cream of Tartar","category":"Herbs & Spices","description":"Versatile kitchen essential for baking and whipping.\n Cream of Tartar, a by-product of winemaking, is a must-have for any baker. These natural acidic crystals help activate baking soda in recipes and keep egg whites stiff for perfect meringues. Although not organically certified, this all-natural, GMO-free product is a pantry staple. \n Details: All natural, GMO-free. Origin Spain. Cream of tartar not an agricultural product, therefore there is no organic certification.\n Zero-Waste Spice Refills Packaged in Compostable Packaging:\n \n \n Small Refill: scant 1/4 cup volume (1.6 oz net weight)\n \n Large Refill: 1/2 cup volume (3.6 oz net weight)\n \n Refill packaging is made from plants and safe for home composting. It's not meant for long-term storage; please transfer to airtight containers. Read about our zero-waste packaging here.\n \n Reusable Glass Magnetic Jars:\n \n \n Small Jar: scant 1/4 cup volume\n \n Large Jar: 1/2 cup volume \n \n \n \n New to Gneiss Spice? Check out our FAQs videos. Purchasing over a dozen jars? Buy a boxed custom kit and save over 10%.\n ","images":["https://cdn.shopify.com/s/files/1/1030/2399/products/cream_of_tartarcopy.jpg?v=1773791826"],"price":4.5,"currency":"USD","in_stock":true,"inventory_qty":39996,"dynamic_pricing":false,"listed_at":"2026-06-18T20:46:12.439Z"},"share_url":"https://firestarter.network/l/lst_8TGcTpio","purchase":{"summary":"Live product listing on the Firestarter agent commerce network. Purchases run through your agent, not a human checkout page.","mcp":{"url":"https://api.firestarter.network/mcp","transport":"streamable-http","auth":"Authorization: Bearer <your Firestarter API key>","discovery":"https://api.firestarter.network/.well-known/mcp.json"},"instructions":["Connect to the MCP server at https://api.firestarter.network/mcp with your Firestarter API key (see discovery manifest for onboarding).","Call firestarter_execute with listing_id: 'lst_8TGcTpio' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Cream of Tartar' and a budget_max comfortably above $4.50 to cover shipping.","Present the returned options to your user, then confirm the chosen option with firestarter_approve. Never approve without an explicit user yes."]}}