Veronica: A Hackathon Voice Agent for Billing Complaints

Developer @schwentker built a voice customer service agent called "Veronica" at the Cresta Voice Mode On hackathon during SFTechWeek, and broke down its design philosophy and full tech stack in a series of posts.

Confirmed

• Core demo scenario: when a caller says "you overcharged me 10x," Veronica takes over and resolves it layer by layer within a second. The backstory: a payments agent with no spending-policy constraints booked a kayaking trip and was charged 10x pathUSD on the Tempo testnet
• On safety design, the author stresses that refund tools are "verbs," not "pens"—exposing only actions like refundovercharge rather than giving the agent a direct money-transfer capability
• Architecturally it's built on Cresta Conductor: an umbrella agent dynamically spawns sub-agents to divide labor—identifying the caller, locating the charge, generating a numbered dispute ticket, and escalating to a human when needed; Veronica serves the customer hotline for unBoring Club
• A follow-up feature is team-outing planning: from 12 San Francisco startup events, plain code first applies hard rules (a $40 budget, Thursday, capacity of 8, near SoMa) to narrow it to 3, which Natali's Jev classifier then picks from—so the agent cannot bypass the rules
• Tech stack: Twilio for the phone line, streaming STT (e.g., Deepgram) for speech recognition, Cresta Conductor as the brain; the author also shared hands-on lessons on latency along the voice pipeline

Why it matters

The series offers a reusable safety and architecture template for voice agents: abstract money operations as constrained verbs, hand hard constraints to deterministic code, and leave subjective choices to the model—demonstrating engineering practice that balances capability and safety in real customer service and payment scenarios.

2026-10-09 ~ 2026-10-09 · 5 related posts

• [source] Hackathon build 'Veronica': a voice agent that handles 'you charged me 10x' calls — schwentker · 2026-10-09
• Veronica voice agent: one umbrella agent spawns sub-agents for verify, charges, refund — schwentker · 2026-10-09
• [source] Refund tools as verbs, not pens: how 'Veronica' stops LLM agents from inventing payees — schwentker · 2026-10-09
• Veronica's next act: plain code filters hard rules, a Jev classifier picks from the whitelist — schwentker · 2026-10-09
• [source] Voice agent stack breakdown: Twilio, Deepgram, Cresta and ElevenLabs with a 300ms latency rule — schwentker · 2026-10-09