{"type":"firestarter.listing","listing":{"id":"lst_IvCpRNZG","product_name":"Architect BB Fountain Pen Nib","category":"Fountain pens","description":"Effortless big, juicy lines make this my go-to for sketching and everyday use. The Architect nib is the opposite of the Italic nib, featuring a broad cross stroke and a thin down stroke. This nib is a BB (double broad), delivering beautiful line variation with strokes measuring around 1.2mm at their thickest (horizontal) and 0.3mm on the downstroke. For even greater versatility, you can flip the nib upside down to create super fine hairline strokes.\nMade exclusively for our fountain pens, all nibs are tipped with hard-wearing iridium for effortlessly smooth writing and are plated in 14k gold for a classic, elegant finish. Plus, every nib is interchangeable, allowing you to effortlessly switch styles whenever inspiration strikes.","images":["https://cdn.shopify.com/s/files/1/0089/6129/4417/files/fountain-pen-nib-architect-b.jpg?v=1737634482"],"price":26,"currency":"USD","in_stock":true,"inventory_qty":19998,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:23.499Z"},"share_url":"https://firestarter.network/l/lst_IvCpRNZG","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_IvCpRNZG' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Architect BB Fountain Pen Nib' and a budget_max comfortably above $26.00 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."]}}