{"type":"firestarter.listing","listing":{"id":"lst_ZdVxShla","product_name":"Refillable Ink Cartridges (pack of 5)","category":"Fountain pens","description":"Keep your Studio Fountain Pen or Studio Pocket Fountain Pen filled and ready to write with this set of reusable ink cartridges. Each pack includes five high-quality cartridges and a handy syringe attachment to make refilling a breeze.\nChoose from:\n\n\nPre-filled with Deep Black: Our best-selling, rich black ink, ready to pop straight into your pen.\n\nEmpty cartridges: Ideal if you’d like to fill them with your own favourite fountain pen ink – perfect for colour lovers and creative souls.\n\nGood for your pen, and better for the planet – simply refill and reuse.","images":["https://cdn.shopify.com/s/files/1/0089/6129/4417/files/refillable-ink-cartridges-deep-black.png?v=1747402055","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/refillable-ink-cartridges-deep-empty.png?v=1747402055"],"price":4,"currency":"USD","in_stock":true,"inventory_qty":19998,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:23.593Z"},"share_url":"https://firestarter.network/l/lst_ZdVxShla","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_ZdVxShla' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Refillable Ink Cartridges (pack of 5)' and a budget_max comfortably above $4.00 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."]}}