Vouch

Voice-recorded payment protection. Vera — an AI mediator — captures the deal in both parties' voices. Stripe holds the money safely until the item arrives, then releases it on voice-confirmed receipt.

Try it live at vouch.fund · Chrome extension · How it works · Submitted to ElevenHacks Hack #9: Stripe (May 15–21 2026)

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The pitch

Selling a $400 phone to a stranger on Facebook Marketplace. Hiring a freelancer who might ghost on the invoice. Vouch holds the buyer's money safely while Vera captures the agreement in both parties' voices — then releases it on voice-confirmed receipt, so the seller actually gets paid on time.

When a deal goes wrong, Vouch doesn't arbitrate from text trails. Vera replays the seller's actual recorded commitment — "Marcus said: no scratches, original box" — and the system resolves from voice evidence, not he-said / she-said.

Two ICPs: high-value P2P sellers (phones, watches, used Macs) and freelancers (designers, devs, copywriters who've been ghosted on the invoice).

How it works

flowchart LR
    A[Buyer speaks deal<br/>with Vera] --> B[Seller listens<br/>+ agrees / counters]
    B --> C[Joint sign-off:<br/>both voice-confirm]
    C --> D[Stripe holds $<br/>safely]
    D --> E{Receipt<br/>OK?}
    E -->|Yes| F[Voice-confirm release<br/>→ Stripe transfers to seller]
    E -->|No| G[Vera mediates dispute:<br/>replays original agreement,<br/>gathers evidence,<br/>routes resolution]
    G -->|Buyer favour| H[Stripe refunds]
    G -->|Seller favour| F
    G -->|Split| I[Stripe partial capture]

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Every state transition (DRAFT → AWAITING_SELLER → AGREED → MONEY_HELD → RELEASED) is server-side guarded. Disputed deals freeze the money until resolution.

Vera as agent

Vera isn't a chatbot tied to a single transcript. She's the same voice identity across five sequential ConvAI sessions — buyer intake, seller acceptance, joint sign-off, voice-confirmed receipt, and dispute mediation — each with its own system prompt and tool surface but the same Samara X voice from the ElevenLabs Voice Library, so the user experiences one continuous mediator across the deal's lifecycle.

Twelve server-side tools back her: deal lookup, term extraction, lock-money, release-money, refund, dispute-open, evidence-attach, and so on. The voice IS the binding record — Scribe v2 Realtime transcribes every commitment to immutable text the moment it leaves the speaker's mouth, and the resolution layer replays the original audio when a deal goes sideways.

For cross-border deals, Vera reads the buyer's terms in the seller's native language via Multilingual TTS — the in-flight letter-by-letter language morph is the demo's hero animation.

Money flow

Vouch sits on Stripe Connect Express as the platform; sellers are connected accounts. The hold mechanic is PaymentIntents with manual capture: authorise the buyer's card, hold the amount, capture (release) or cancel (refund) on resolution. Application Fees retain a flat 2.9% at capture — zero markup on Stripe's processing rate.

When money locks, Vouch mints a frozen Stripe Issuing virtual card sized to the held amount. Voice-confirmed receipt activates it. Stripe's realtime issuing_authorization.request webhook hits a dedicated hot-path endpoint that compares each spend against the deal's agreed merchant category and responds within the 2-second decision window — Vera doesn't just hold the money, she gatekeeps how it gets spent. This inverts the usual agentic-commerce pattern: instead of the agent paying with a card, Vera mints one for the seller.

The Stripe webhook handler is the async source of truth: signature-verified against the raw body, multi-secret for platform vs connected-account scopes, KV-backed idempotency with a 4-day TTL on event.id.

Stack

• Next.js 16 App Router · TypeScript · Tailwind 4 · Vercel
• ElevenLabs — ConvAI (Vera's 5 sessions, 12 server-side tools), Voice Library (Samara X — locked brand voice), v3 Conversational (expressive audio tags at money-movement beats), Scribe v2 Realtime (voice → binding terms record), Multilingual TTS (cross-border letter-by-letter morph), Sound Generation (lock-thunk, release-bell, dispute-chime)
• Stripe — Connect Express (custodial), PaymentIntents manual capture (the hold), Application Fees (2.9% platform fee), Issuing (frozen virtual card per deal), Issuing realtime auth (sub-2s decision endpoint), Webhooks (state machine source of truth), Agent Toolkit (restricted-key blast-radius enforcement)
• Chrome extension (manifest v3) — injects "Pay with Vouch" on eBay listings · install instructions
• Vercel KV — production persistence (in-memory fallback for local dev)

Run it locally

pnpm install
cp .env.example .env.local   # fill in Stripe + ElevenLabs keys
pnpm dev                      # → http://localhost:3000
pnpm build                    # next build --webpack

Stripe test mode + ElevenLabs free tier are sufficient for the full flow.

License

MIT — see LICENSE.