About Nexbid
Nexbid is the reference implementation of Protocol Commerce, an open initiative for interoperable, auditable commerce protocols for AI agents. Its MCP integration lets compatible LLMs search, browse, and purchase products through a marketplace, with privacy-focused operation and formally verified core security properties.
Key features
- 01MCP-native product discovery and purchasing
- 02AdCP and AMDP protocol specifications
- 03TypeScript SDK and validators
- 04Browser tools through WebMCP
- 05Lean 4 proofs of core properties
Use cases
- 01Searching and browsing marketplace products with an MCP-compatible LLM
- 02Facilitating product purchases through an AI agent
- 03Building commerce integrations with the AdCP SDK
MCP support
Nexbid provides an MCP endpoint for compatible LLMs to search, browse, and purchase products through its marketplace. The repository also includes a WebMCP reference for exposing commerce tools to in-browser AI agents.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://mcp.nexbid.dev/mcpclaude mcp add --transport http protocol-commerce https://mcp.nexbid.dev/mcp{"mcpServers":{"protocol-commerce":{"type":"http","url":"https://mcp.nexbid.dev/mcp"}}}Open in Cursor{"servers":{"protocol-commerce":{"type":"http","url":"https://mcp.nexbid.dev/mcp"}}}Open in VS Code{"mcpServers":{"protocol-commerce":{"type":"http","url":"https://mcp.nexbid.dev/mcp"}}}{"mcpServers":{"protocol-commerce":{"serverUrl":"https://mcp.nexbid.dev/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
Tools
19| Parameter | Type | Required | Description |
|---|---|---|---|
| query | string | Yes | Natural language product or recipe query |
| content_type | enum | No | Filter by content type: product, recipe, or all (default)all | product | recipe | service |
| intent | enum | No | User intent for the searchpurchase | compare | research | browse |
| budget_max_cents | integer | No | Maximum budget in cents (e.g. 20000 for CHF 200) |
| budget_min_cents | integer | No | Minimum budget in cents |
| currency | enum | No | Currency for budget filteringCHF | EUR | USD | GBP |
| geo | string | No | ISO 3166-1 alpha-2 country code (default: CH) |
| category | string | No | Filter by product category |
| brand | string | No | Filter by brand name |
| max_results | integer | No | Maximum number of results (1-50, default: 10) |
| previous_queries | array | No | Previous queries in this search session for multi-turn refinement (oldest first, max 10). Example: ["running shoes", "waterproof only"] |
| agent_id | string | No | Agent identifier — used for analytics-attribution (e.g. "claude-3.5", "gpt-4o", "perplexity"). Optional but strongly recommended so publishers/advertisers can see which AI agents drive their traffic. |
| session_id | string | No | Session token to correlate multiple tool-calls from the same conversation. Optional. Useful for multi-turn analytics. |
Details
From the project READMEProtocol Commerce
The open infrastructure for agent-native commerce.
Protocol Commerce is an open initiative to create standardized, auditable, and interoperable protocols for AI agent-driven commerce. This repository contains the specification, SDKs, and technical manifesto.
Contents
| Directory | Description |
|---|---|
manifesto/ | Why open protocols matter for commerce — principles, landscape analysis, and rationale |
adcp-spec/ | AdCP v0.1.0 — Agentic Discovery Commerce Protocol specification, JSON schemas, and examples |
adcp-sdk-typescript/ | TypeScript SDK: types, validators, client, and scoring reference implementation |
webmcp-reference/ | WebMCP browser integration: expose commerce tools to in-browser AI agents via navigator.modelContext |
amdp-spec/ | AMDP v0.1.0 — Agent Mandate Discovery Protocol: cross-vertical authorization spec, JSON schemas, and example mandates |
agentic-kit/ | Agentic Kit — the trust layer: building blocks for verifiable + auditable AI agents |
lean-verification/ | Lean 4 formal verification — 47 theorems proving auction/budget/wallet/policy correctness, lake build-checkable |
Quick Start
npm install @protocol-commerce/adcp-sdk
import { AdcpClient } from '@protocol-commerce/adcp-sdk';
const client = new AdcpClient({
serverUrl: 'https://mcp.nexbid.dev',
apiKey: 'your-api-key',
});
const results = await client.search({
query: 'organic olive oil',
intent: 'purchase',
geo: 'CH',
});
The Problem
AI agents are becoming the primary interface for product discovery and purchase. The protocols powering this shift — OpenAI's ACP, Google's UCP — are proprietary and platform-controlled. Publishers have no representation. There is no open standard.
Protocol Commerce fills this gap.
Read the full Technical Manifesto →
Key Principles
- Open by Default — MIT-licensed, auditable, forkable
- Publisher Parity — Publishers are first-class protocol participants
- Privacy Native — Context signals, not user profiles
- Transparent Scoring — Public formula:
score = 0.4×bid + 0.4×relevance + 0.2×quality
Reference Implementation: Nexbid
Nexbid is the production-grade reference implementation of Protocol Commerce, built by digital opua GmbH (CHE-435.289.702, Switzerland).
| Metric | Status |
|---|---|
| MCP Integration | Native — full commerce lifecycle |
| Formal Verification | Lean 4 — core security properties proven |
| Privacy | Cookie-free, Swiss-hosted, nDSG + GDPR compliant |
| AI Scoring | Multi-provider, model-agnostic |
| Phase | Production-grade closed beta |
Connect Any LLM
{
"mcpServers": {
"nexbid": {
"url": "https://mcp.nexbid.dev/mcp",
"transport": "streamable-http"
}
}
}
Any MCP-compatible LLM (Claude, GPT-4, Gemini) can directly search, browse, and purchase products through the Nexbid marketplace.
Why Formal Verification?
Nexbid is the only commerce platform whose core security properties are mathematically proven in Lean 4 — not just tested, but proven correct for all possible inputs.
→ Technology details · How Nexbid compares
Sponsors
| Sponsor | Role |
|---|---|
| Nexbid | Initiator, reference implementation, initial maintainer |
License
MIT — Use it, fork it, build on it. No strings attached.
Links
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.