VibeCart

Commerce infrastructure for AI-built apps and AI agents.

VibeCart lets a merchant keep their existing app and Stripe account while adding a small, inspectable commerce layer that AI agents can discover and use. Payments settle directly to the merchant's Stripe account; VibeCart does not need to become merchant of record.

The architecture is protocol-first: one trusted commerce backend, then thin MCP/UCP/client adapters around it.

Live production surface

Generic MCP

Endpoint: https://vibecart.vercel.app/mcp

Tools:

• vibecart.list_products

• vibecart.get_product

• vibecart.get_integration_instructions

• vibecart.create_checkout

vibecart.create_checkout supports both the legacy single-product input and a trusted multi-item items[] input. Product prices are resolved on the server; callers do not supply real transaction prices.

Generic MCP clients should use /mcp.

Durable cart

VibeCart's Neon-backed cart is live in production:

• POST /api/cart

• GET /api/cart/:id

• PATCH /api/cart/:id

• DELETE /api/cart/:id

• POST /api/cart/:id/checkout

The cart uses trusted server-side repricing, idempotent creation, optimistic version checks, expiration, multi-item state, and cart-to-Stripe Checkout handoff.

UCP

• Discovery: https://vibecart.vercel.app/.well-known/ucp

• UCP-aware MCP transport: https://vibecart.vercel.app/ucp/mcp

• Released protocol target: UCP 2026-04-08

Production advertises released catalog and cart capabilities. Current cart tools are:

• create_cart

• get_cart

• update_cart

• cancel_cart

UCP calls require meta.ucp-agent.profile and capability negotiation. Do not point an ordinary MCP client at /ucp/mcp.

The order pipeline and released-schema get_order adapter also exist, but get_order remains hidden until its VibeCart Cloud lookup and real merchant permalink dependencies are configured. VibeCart does not advertise optional capabilities before their runtime dependencies are ready.

Stripe checkout and orders

• Trusted multi-line Stripe Checkout creation is supported.

• Stripe webhook signatures are verified before paid events enter the post-payment pipeline.

• Delayed-payment completion is handled separately so orders are not created prematurely.

• Paid Checkout line items are normalized into durable order records when VibeCart Cloud forwarding is configured.

• Trusted merchant product IDs survive Checkout through Stripe Product metadata.

Related MCP server: ACP Commerce MCP Server

Agent-client distribution

VibeCart does not build a different commerce engine for every model. OpenAI/Codex/ChatGPT, Claude, Gemini, VS Code, Cursor, and other MCP clients connect to the same backend.

See:

• docs/integrations/agent-clients.md

• integrations/mcp-clients.json

• https://vibecart.vercel.app/mcp-clients.json

Provider adapters are CI-checked to keep Stripe/database secrets and duplicated commerce logic out of client configuration.

VibeCart Cloud

VibeCart Core is free to self-host. VibeCart Cloud is the optional $29/month managed layer for merchants that want VibeCart to operate the recurring plumbing.

Current Cloud capabilities include:

• durable verified commerce events

• durable normalized paid-order records and order history

• server-to-server order lookup

• signed merchant fulfillment webhooks

• delivery history and bounded retries

• monitoring/alerts and support workflows

Cloud workspace: https://vibecart-cloud-uupzkh.v2.appdeploy.ai/

Merchant checkout revenue still settles directly to the merchant's Stripe account. VibeCart takes no percentage of merchant sales.

Quick start

npm install
npm run dev

Without a Stripe secret, Checkout runs in clearly labeled demo mode. For live payments, configure STRIPE_SECRET_KEY in the hosting provider's secret/environment settings. Never commit secret values.

Useful public endpoints:

• /mcp — generic MCP transport/discovery

• /api/cart — durable cart creation

• /.well-known/ucp — UCP business discovery

• /ucp/mcp — UCP-aware MCP transport

• /mcp-clients.json — machine-readable client compatibility manifest

• /llms.txt — concise machine-readable integration notes

• /agents.md — agent-facing guide

• /api/health — boolean readiness state without secret values

• /cloud — managed Cloud offer

Security model

• Merchant owns the Stripe account and receives merchant funds directly.

• Trusted prices come from server-side merchant catalog state.

• Client-supplied pricing is disabled by default and is prototype-only when explicitly enabled server-side.

• Stripe webhook signatures are verified before post-payment processing.

• Cart state is durable and versioned rather than trusted from the browser/agent.

• Cloud integration credentials remain server-side.

• Public health/discovery endpoints expose readiness booleans/capabilities, not credential values.

• Optional UCP capabilities are advertised only when their runtime dependencies are valid.

Protocol conformance

CI pins the released UCP v2026-04-08 source and executes VibeCart's real mappers through the official ucp-schema validator. Cart success/error payloads, catalog responses, discovery, and the private order mapper have release-pinned conformance gates.

Current reference limits

• The merchant catalog is still a small reference catalog rather than a complete multi-merchant catalog service.

• Inventory, automated tax calculation, shipping-rate calculation, returns/refunds, and a complete fulfillment lifecycle are not finished platform services.

• Public UCP order lookup remains activation-gated until its Cloud/permalink runtime dependencies are configured.

• Next.js App Router is the reference implementation; other frameworks should use adapters around the same Core protocol surface rather than fork commerce logic.

North star

VibeCart: commerce infrastructure for every AI agent. Build once. Sell everywhere AI can act.

License

MIT — free to use, modify, distribute, sublicense, and sell under the license terms.