Install the Closient MCP Server

The Closient MCP server lets any AI agent that speaks the Model Context Protocol call Closient directly — validate GTINs, resolve them to product pages, look up catalog data, search by natural language, compare products, find nearby availability, and (with auth) generate Digital Link URLs for QR codes. The server is hosted by Closient — you do not install or run anything locally. Pointing your MCP client at the server URL is enough.

	Value
Server URL (Streamable HTTP)	`https://www.closient.com/mcp/http`
Server URL (legacy SSE)	`https://www.closient.com/mcp/sse`
Health probe	`https://www.closient.com/mcp/health`
Authorization Server metadata	`/.well-known/oauth-authorization-server`
Protected Resource metadata	`/.well-known/oauth-protected-resource`

Use https://www.closient.com/mcp/http for new integrations. The /mcp/sse endpoint is kept for backwards compatibility with older MCP clients that haven’t adopted the Streamable HTTP transport yet.

Tier 1 — first-class clients

These clients ship MCP support out of the box. Pick the matching tab and follow the snippet — no extra packages, no local server, no JSON hand-editing.

Claude Code
Claude Desktop
Claude.ai
Cursor
VS Code

Run once from a terminal:

claude mcp add closient --transport http https://www.closient.com/mcp/http

That’s it. claude mcp list should now show closient and the tools become available to any Claude Code session in this workspace.To remove later: claude mcp remove closient.

Open Claude Desktop > Settings > Connectors (formerly “Custom Connectors”).
Click Add custom connector.
Paste the server URL:
```
https://www.closient.com/mcp/http
```
Save. Claude Desktop will discover the tools and prompt for OAuth the first time you call generate_qr_url (see Authentication).

For a deeper walkthrough see Anthropic’s custom connectors guide.

Open claude.ai and go to Settings > Connectors > Custom Connectors.
Click Add custom connector.
Paste:
```
https://www.closient.com/mcp/http
```
Save. The connector is available to all chats on this account.

One-click install:

Add Closient to Cursor

Click to open Cursor with the Closient server pre-filled. You’ll see a confirmation prompt before it’s added.

Manual install: open ~/.cursor/mcp.json (or use Settings > MCP > Add new server) and add:

{
  "mcpServers": {
    "closient": {
      "url": "https://www.closient.com/mcp/http"
    }
  }
}

Run from a terminal:

code --add-mcp '{"type":"http","name":"closient","url":"https://www.closient.com/mcp/http"}'

VS Code 1.95+ ships built-in MCP support. The Closient server is added to your user settings.json under "mcp.servers" and available to GitHub Copilot Chat and any MCP-aware extension.To add manually, open Settings > MCP > Edit settings.json and add:

{
  "mcp": {
    "servers": {
      "closient": {
        "type": "http",
        "url": "https://www.closient.com/mcp/http"
      }
    }
  }
}

Tier 2 — Windsurf

Windsurf reads a mcp_config.json file in the project root (or the global ~/.codeium/windsurf/mcp_config.json). Add:

{
  "mcpServers": {
    "closient": {
      "url": "https://www.closient.com/mcp/http"
    }
  }
}

Restart Windsurf and the Closient tools appear in the Cascade panel.

Tier 3 — generic JSON config

Any MCP-compatible client (Cline, Zed, Trae, Continue, custom agents built on the MCP Python or TypeScript SDKs, etc.) can connect with the generic Streamable HTTP entry below. Paste it into whatever configuration format the client uses for MCP servers.

{
  "name": "closient",
  "transport": "http",
  "url": "https://www.closient.com/mcp/http"
}

If the client only supports the older HTTP+SSE transport, use:

{
  "name": "closient",
  "transport": "sse",
  "url": "https://www.closient.com/mcp/sse"
}

What you get

Once installed, the client discovers the following tools (no auth required for discovery):

Tool	Auth	Use case
`ping`	none	Health probe — returns `pong`.
`validate_gtin`	none	Check a GTIN’s structure and check digit.
`resolve_gtin`	none	Apply the resolver-rule hierarchy and return the destination URL.
`lookup_product`	none	Look up structured product data by GTIN.
`search_products`	none	Natural-language search across the catalog, optionally with geo boosting.
`get_product_detail`	none	Rich product record — attributes, images, ingredients, nutrition.
`compare_products`	none	Side-by-side comparison of 2-5 products.
`check_availability`	none	Find nearby physical stores carrying a GTIN.
`generate_qr_url`	OAuth	Build the canonical Digital Link URL to encode in a 2D barcode.

Full input/output schemas and examples are in the Tool Reference.

Authentication

The first eight tools above work immediately — no token, no setup. generate_qr_url requires an OAuth 2.1 bearer token with the qr:generate scope. When you (or your agent) call it without a token, Closient returns 403 Forbidden with a WWW-Authenticate header that tells the MCP client where to start the OAuth flow. Most first-class MCP hosts (Claude Desktop, Cursor, VS Code) handle the prompt-and-retry transparently — see Authentication for the full flow.

Verifying the connection

After installing, ask your AI tool something like:

Use the Closient MCP server to validate GTIN 00614141123452.

The agent should call validate_gtin and report the GTIN is valid (it’s a real GS1 test code). If you get a “no MCP server named closient” error, restart the client — most hosts only pick up new server configs on launch. A direct sanity check from a terminal:

curl -sS https://www.closient.com/mcp/health

A 200 OK response means the hosted server is reachable from your network.

Troubleshooting

Symptom	Likely cause
Client can’t connect	Corporate proxy or firewall blocking `closient.com`. Try `curl https://www.closient.com/mcp/health` from the same host.
`tools/list` returns empty	Client is configured for `transport: stdio` instead of `http`. Closient is a remote server only.
`generate_qr_url` always returns 403	Token missing the `qr:generate` scope. Re-run the OAuth flow and accept the consent screen — older tokens issued without the scope must be refreshed.
OAuth pop-up never appears	Client doesn’t honour the `WWW-Authenticate` header (some self-built MCP clients). Mint a token manually via OAuth Authentication and pass it in `Authorization: Bearer <token>`.
401 instead of 403	Token is expired. Access tokens last 24 h, refresh tokens 90 d.

Reference

Tool Reference — input/output schemas for every tool.
Authentication — OAuth 2.1 step-up flow.
MCP Error Contract — how failures surface over JSON-RPC.
MCP Identity Propagation — agent vs. end-user actor in audit logs.
MCP Tool Annotations — readOnlyHint / destructiveHint semantics.
Model Context Protocol spec — the underlying open standard.

​Tier 1 — first-class clients

Add Closient to Cursor

​Tier 2 — Windsurf

​Tier 3 — generic JSON config

​What you get

​Authentication

​Verifying the connection

​Troubleshooting

​Reference

Tier 1 — first-class clients

Tier 2 — Windsurf

Tier 3 — generic JSON config

What you get

Authentication

Verifying the connection

Troubleshooting

Reference