{"type":"firestarter.listing","listing":{"id":"lst_hjLkl-Jk","product_name":"IKKAKU by Nahvalur 夜羽 Ye-Yu Urushi Raden Pen","category":"Fountain Pen","description":"Ye-Yu (夜羽), which directly translates to Nightly Feathers, is the first luxury fountain pen from IKKAKU by Nahvalur.The rounded, cylindrical body profile is based on the Nahvalur Nautilus pen design with layered, deep black urushi and exquisitely inlaid raden that mimics the feathers of nightingales.Each Ye-Yu Urushi Raden Pen arrives in beautiful wood box, and includes a Nahvalur converter. For maximum ink capacity, this pen can be converted to fill with an eyedropper by removing the converter and applying a small amount of silicone grease to the section threads.'Ikkaku' is the Japanese word for narwhal and the mark of luxury expressed in urushi and raden. IKKAKU by Nahvalur is yet another testament to Nahvalur’s unwavering dedication to luxury writing instruments with high craftsmanship and artistryIKKAKU by Nahvalur Ye-Yu Urushi Raden Pen Specifications:\nEdition: 2023 Limited Edition\nPen Material: Black urushi with inlaid raden decoration\nTrims and Clip: Gold Trim\nNib: No. 6 size 14K Gold Nib available in F or M point sizes, plastic feed\nFilling System: Cartridge/Converter (included); can be converted to eyedropper\nPen Length, Closed: 5.9 in. / 150mm\nPen Length, Open (Cap Off): 5.24 in. / 133mm\nPen Length, Open (Cap Posted): Cannot be posted\nPen Barrel Diameter: 0.51 in. / 13mm\nPen Grip Section Diameter: 0.39 in. - 0.45 in. / 10mm - 11.5mm\nPen Weight: 1.3 oz. / 36.85g\nPackaged in a wooden Ikkaku gift box with warranty card\n","images":["https://cdn.shopify.com/s/files/1/0575/7177/files/IMG-9786.jpg?v=1757662438","https://cdn.shopify.com/s/files/1/0575/7177/files/IKKAKU-by-Nahvalur-Ye-Yu-Ye-Yu-Urushi-Raden-Pen.jpg?v=1757662438","https://cdn.shopify.com/s/files/1/0575/7177/files/IKKAKU-by-Nahvalur-Ye-Yu-Ye-Yu-Urushi-Raden-Pen-2.jpg?v=1757662438","https://cdn.shopify.com/s/files/1/0575/7177/files/IKKAKU-by-Nahvalur-Ye-Yu-Ye-Yu-Urushi-Raden-Pen-3.jpg?v=1757662438","https://cdn.shopify.com/s/files/1/0575/7177/files/IKKAKU-by-Nahvalur-Ye-Yu-Ye-Yu-Urushi-Raden-Pen-4.jpg?v=1757662438"],"price":799,"currency":"USD","in_stock":true,"inventory_qty":9999,"dynamic_pricing":false,"listed_at":"2026-06-18T20:46:00.822Z"},"share_url":"https://firestarter.network/l/lst_hjLkl-Jk","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_hjLkl-Jk' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy IKKAKU by Nahvalur 夜羽 Ye-Yu Urushi Raden Pen' and a budget_max comfortably above $799.00 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."]}}