{"type":"firestarter.listing","listing":{"id":"lst_foEI3RmQ","product_name":"Lefty-Fine Nib #6","category":"Nib","description":"Crafted in Germany by some of the world's most exceptional nib makers, this Nemosine nib features a fine tip in what is commonly referred to as a #6 size. This lefty-fine nib has a subtle oblique taper on the tip that some left-handed writers find convenient. \nOur Collar &amp; Feeder option arrives with the nib pre-installed into housing with feeder, compatible with our Model-C fountain pens. ","images":["https://cdn.shopify.com/s/files/1/1237/1088/products/Lefty-Fine.jpg?v=1581611591"],"price":19,"currency":"USD","in_stock":true,"inventory_qty":9999,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:18.771Z"},"share_url":"https://firestarter.network/l/lst_foEI3RmQ","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_foEI3RmQ' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Lefty-Fine Nib #6' and a budget_max comfortably above $19.00 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."]}}