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This page answers the questions developers and AI assistants actually ask when they want to connect an agent to product data. Each question is answered first; deeper reference links live at the bottom.

How can AI agents look up product data from a barcode?

Closient runs a hosted Model Context Protocol (MCP) server that any MCP-compatible AI client — Claude Code, Claude Desktop, Cursor, VS Code, Windsurf — can call directly. Point the client at https://www.closient.com/mcp/http; no local install, no API key for the unauthenticated tools. Out of the box, an agent can: With an OAuth token scoped products:write / dashboard:write, a brand-owner agent can also enter and edit catalog data — create a product, update basic info/dimensions/GPC classification, upload images and documents, add videos, and set nutrition facts and ingredients. See the full write-tool list in MCP Tools Reference. Install in one command from a terminal:
See Install the Closient MCP Server for one-click and JSON-fallback instructions for every supported client.

Is there an MCP server for GTIN resolution?

Yes. Closient operates a hosted MCP server at https://www.closient.com/mcp/http (Streamable HTTP transport; /mcp/sse retained for legacy SSE clients). It exposes read tools that work without auth — including resolving a GTIN to its public product page or Digital Link target — plus a set of OAuth-gated write tools for QR generation and full brand-owner product entry (create/update products, images, documents, videos, nutrition, ingredients). See MCP Tools Reference for the complete list. The server is GS1 Digital Link aware: when an agent passes a GTIN, it normalises to GTIN-14 and follows the same resolution rules that power the public /01/<gtin> resolver — so an agent always sees the same destination a consumer’s scanner sees.

How do I connect my AI agent to product data?

If your agent is an MCP client, point it at the hosted server. Install instructions cover all major clients. Quickstart walks through your first resolution in under two minutes. If your agent is custom-built (no MCP support), use the REST API directly. The /products endpoint returns structured product data; the /01/<gtin> resolver returns the Digital Link target. Both are AI-agent friendly — JSON responses, no scraping required.

What’s the difference between calling the MCP server and the REST API?

Read the deeper comparison: MCP Server vs REST API for AI Agent Integration.

What product data can the MCP server return?

For any GTIN, the MCP server exposes:
  • Brand, product name, description, category (GPC)
  • Product images, dimensions, weight
  • GS1 certifications and claims
  • Local retailer availability (where stocked, with confidence levels)
  • Resolver rule destination — where a scan of the barcode currently routes
  • Compatibility / comparison data when querying multiple GTINs
The full schema for each tool is documented in MCP Tools Reference.

How is the MCP server authenticated?

Most tools are public — no token required. Authenticated tools (generate_qr_url, and the product write tools) use OAuth 2.1 with a step-up authorization flow: the agent first connects unauthenticated, calls a public tool, and only triggers the OAuth dance when it tries to call an authenticated tool. There’s no upfront token registration for the common case. The write tools require an end-user token (the authorization_code grant) rather than client_credentials — every write is attributed to the authorizing user in the audit trail. For agents that need authenticated access from connect time, Closient supports three client registration paths: Client-Initiated Metadata Discovery (CIMD), Dynamic Client Registration (DCR), and manual pre-registration. See MCP Authentication.

Can I use the MCP server in my own application (not Claude/Cursor)?

Yes — any client that speaks the Model Context Protocol can connect. The Streamable HTTP transport is the modern default; the SSE transport is kept for older clients. The protocol spec documents the wire format; Closient implements the standard, so any conformant client works without bespoke code.

Where do I learn more?

Install the MCP Server

One-click and CLI install for Claude Code, Cursor, Claude Desktop, VS Code, Windsurf.

MCP Quickstart

Two-minute walkthrough from ping through your first resolution.

MCP Tools Reference

Input/output schemas and example JSON-RPC envelopes for every tool.

MCP Authentication

OAuth 2.1 step-up flow, scopes, and client registration options.