{"type":"firestarter.listing","listing":{"id":"lst_kepNc4GH","product_name":"HeartField CU8","category":"In-Ear Monitors","description":"\n\n\nHarman-Tuned Neutral Sound\nThe CU8 is meticulously tuned to the Harman neutral target curve and verified with professional artificial-ear measurements. From 20 Hz to 20 kHz, it delivers uncolored, faithful reproduction—whether you’re phase-matching on a master track or enjoying uncompressed audio, you’ll experience studio-monitor–level precision and detail.\n\n\nPUR Vibration Control System\nEquipped with micro-alloy spring suspensions on its mid and low-frequency drivers, the CU8’s PUR Vibration Control System lowers resonance points to enhance density and dynamics. Remarkably, just four balanced armature units achieve the richness and impact you’d expect from configurations with twice as many drivers.\n\n\n\nGold-Plated Brass Acoustic Chamber\nCrafted from precision-milled brass with a density of 8.96 g/cm³—over three times that of standard resin—the CU8’s housing suppresses unwanted vibrations and elevates both tactile feel and acoustic clarity. This rigid chamber ensures the purest signal path from driver to ear.\n\n\nArtisanal Hand-Finishing\nEvery pair of CU8 earphones is shaped and polished by skilled hands. Through careful hammering, grinding, and buffing, each unit becomes a fusion of audio engineering and artisanal artistry—time-honored craftsmanship encoded in metal and form.\n\n\nPremium Detachable Cable\nThe detachable cable features 24 AWG silver-plated, oxygen-free copper (40 strands of 0.005 mm wire per core) with PTFE insulation (dielectric constant 2.1) to minimize distortion. WBT silver-alloy solder ensures rock-solid connections and transparent, full-bandwidth transmission.\n\n\n","images":["https://cdn.shopify.com/s/files/1/0040/7201/3924/files/7f6b1805-9c33-478d-aa2f-06480321b966.jpg?v=1750052619","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/5302311b-57e3-441c-aa47-e7de4a58f976.jpg?v=1750052619","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/bec8b440-1dfb-4f17-99e8-29d403ce2e61.jpg?v=1750052619","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/d2ef8419-30a6-407a-b03e-fe7ab2a12b84.jpg?v=1750052619"],"price":396,"currency":"USD","in_stock":true,"inventory_qty":19998,"dynamic_pricing":false,"listed_at":"2026-06-20T16:26:44.969Z"},"share_url":"https://firestarter.network/l/lst_kepNc4GH","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_kepNc4GH' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy HeartField CU8' and a budget_max comfortably above $396.00 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."]}}