{"type":"firestarter.listing","listing":{"id":"lst_MIJF3UeQ","product_name":"Extra Fine Semi-Flex Fountain Pen Nib","category":"Fountain pens","description":"A beautiful extra fine fountain pen nib with flex! This nib strikes the perfect balance between our Pro Flex and classic fountain pen nibs, offering a smooth writing experience with minimal upkeep. With gentle pressure, it elegantly flexes from 0.5mm to 1.5mm, allowing for expressive line variation.\nMade exclusively for our fountain pens, all nibs are tipped with hard-wearing iridium for effortlessly smooth writing. You can choose between uncoated stainless steel (a sleek silver finish) or 14k gold plating (a classic gold finish) – the difference is purely aesthetic, so both options offer the same exceptional performance. Plus, every nib is interchangeable, allowing you to effortlessly switch styles whenever inspiration strikes.\nIntroducing Our Limited-Edition Ebonite Feed\nLooking for a little something extra for your writing setup? Enter the Ebonite Feed. Unlike our injection-moulded feeds, ebonite is a game-changer for ink flow. Its natural hydrophilic properties (think super ink-grabbing powers) mean it holds more ink, giving you a smoother, wetter writing experience that’s perfect for those who like their pens to glide across the page.\nThis limited-run feed is part of an experimental release – we’ve sourced just a small batch to see what you think. If you’re all about peak performance, this might just be your new favourite upgrade.\nWhy Choose Ebonite?\n\n\nInk-holding champion – More ink means fewer interruptions.\n\n\nPerfect flow – Balanced, smooth, and consistent writing.\n\n\nMade for the curious – If you’re ready to explore the next level of nib performance, this is for you.\n\n\nStock is limited (really limited), so grab yours while you can. And if we sell out, be sure to hit that 'Notify Me' button.","images":["https://cdn.shopify.com/s/files/1/0089/6129/4417/files/fountain-pen-nib-semi-flex-gold.jpg?v=1772120449","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/fountain-pen-nib-semi-flex-stainless-steel.jpg?v=1737634482","https://cdn.shopify.com/s/files/1/0089/6129/4417/files/fountain-pen-feed-comparison.jpg?v=1737633635"],"price":19,"currency":"USD","in_stock":true,"inventory_qty":39996,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:23.455Z"},"share_url":"https://firestarter.network/l/lst_MIJF3UeQ","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_MIJF3UeQ' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Extra Fine Semi-Flex Fountain Pen Nib' 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."]}}