Trojan Horse: AI agents that call mechanics for you, and how Kane CLI caught our bug

Khushi Chandra — Sun, 25 Oct 2026 00:48:25 +0000

The problem
Your car breaks down at night. You search for mobile mechanics and call them one by one: who’s open, who’s close, who won’t overcharge? That’s exactly when time matters most.

What we built
Trojan Horse (“Engine cooked? Help booked.”) is a multi-agent app we built in one day at Kane CLI Hack Day SF:

A Discovery Agent uses OpenAI web search to shortlist mobile mechanics near you.
A Caller Agent places up to 3 calls at the same time using OpenAI Realtime with Vonage/Twilio, asking about availability, arrival time and price, and streams the transcripts to your screen.
Quotes are ranked by price, and you pick one.
A Callback Agent confirms the job. It’s only booked when the mechanic explicitly says yes.

The stack: a React dashboard, a Node orchestrator with SQLite, separate discovery and voice services, and shared zod contracts.

Why we didn’t trust our own AI
A voice agent can easily invent a price, say “booked” when it isn’t, or dispatch twice. So we tested Trojan Horse with Kane CLI against our own plain-English requirements:

Kane read our one-paragraph spec and produced 26 acceptance criteria and 19 requirement-linked browser tests. We didn’t write any by hand.
A test-mode scenario switch makes the simulated mechanics misbehave on purpose (a failed call, an unknown price or ETA, a late arrival, a booking that’s never confirmed), so every rule can be checked repeatably.
Two tests read the browser’s network traffic to prove it never calls Twilio, Vonage or OpenAI directly.
Every run seals an evidence pack: a screenshot per step, network logs, and Kane’s diagnosis.
A required CI check replays the suite on every PR. The latest run on main passed all 19 tests.

What Kane caught
We added one rule: if a mechanic doesn’t say whether they’re free, show “Unknown”. Kane designed a test, and it failed. The mechanic said “I’m not sure anyone is free right now”, and our app showed “Available now: No”. Our shared contract stored availability as true or false, so both the simulated and the live voice path turned “unsure” into “unavailable”. A real driver would have been misled. We made the field nullable and fixed the UI, and the same test passed. Both evidence packs are in the repo.

Code: https://github.com/RamyaRamachandran-driod/emergency-caller

DEV Community: Khushi Chandra

Trojan Horse: AI agents that call mechanics for you, and how Kane CLI caught our bug

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