SilverLine

Every voice bot hangs up on Grandma first. It mistakes thinking for finished: default turn-taking cuts off slow speakers, mangles drug names, and leaves zero proof that anything was agreed. Families end up calling clinics on their parents' behalf, and front desks drown in reminder phone tag. SilverLine is the voice line that waits. An elderly patient calls one number — no app, no account, even a landline works — and a slow, warm agent confirms the clinic visit, teaches back each medication one at a time, and ends every call with a signed voice receipt the family can verify online. Nothing books without a slow read-back of the full visit and an explicit "yes"; any edit to a receipt breaks its HMAC-SHA256 signature. Three engineering choices make it different: a slow-safe turn-taking envelope (1200/3500 ms) with semantic interruption handling so pauses are waited through and backchannels never kill a reply; per-stage keyterm narrowing that boosts clinic names, then drug names like Metoprolol succinate, updated live mid-call; and proof-gated action backed by transactional booking and server-side caller memory. It is proven, not promised: a live 8-minute PSTN call to the public number produced a real booking, a 3-for-3 medication teach-back, and a receipt that verifies true — all for about sixty cents of AssemblyAI time. The browser demo runs the same loop against the same backend, with toggles that let judges feel the difference between fast and patient modes themselves. Built with the AssemblyAI Voice Agent API, Twilio voice/SMS/SIP trunking, Next.js, Supabase, and Vercel. Next: supervised pilots with older adults, a single-clinic trial priced per confirmed visit, then pharmacy refills.