# barcode — barcode & QR tools MCP server

Barcode/QR decode, render and product-code (GTIN) validation for AI agents over the
[Model Context Protocol](https://modelcontextprotocol.io). One WASM engine
(zxing-cpp via [`zxing-wasm`](https://www.npmjs.com/package/zxing-wasm)) does both render and
decode — fully headless.

**Use the hosted endpoint — no install, no local process:**

```
https://mcp.casuyi.com/mcp
```

MCP `2026-07-28` (2025-era clients supported too), stateless Streamable HTTP, works with
Claude Code, Claude Desktop, Cursor, VS Code, and any MCP client.

## Tools

| Tool | What it does |
|---|---|
| `list_formats()` | Table of supported symbologies and their capabilities |
| `validate_gtin(code)` | Product-code rules: length + mod-10 checksum → `{valid, type, normalized}` (EAN-13/8, UPC-A/E, ITF…) |
| `render_barcode(text, format, scale?)` | Render any supported symbology as base64 PNG. Every render is decoded back before returning — failures come with a `warning`, never silently |
| `decode_barcode(image_base64, formats?)` | Detect + decode all barcodes in an image → `[{format, text}]` — QR, Aztec, DataMatrix, Code128/39/93, EAN-13/8, UPC-A/E, ITF, PDF417, Codabar |

## Connect

**Claude Code**

```bash
claude mcp add barcode --transport http https://mcp.casuyi.com/mcp
```

**Claude Desktop** — Settings → Connectors → *Add custom connector* → URL above.

**Cursor / VS Code (Copilot) / Windsurf / any `mcpServers` JSON client**

```json
{
  "mcpServers": {
    "barcode": { "type": "http", "url": "https://mcp.casuyi.com/mcp" }
  }
}
```

## Pricing

**All tools are completely free.** No API key, no payment, no signup.

A free service by [Casuyi](https://casuyi.com).


## Try it right now (curl, no client needed)

```bash
curl -sS -X POST https://mcp.casuyi.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"validate_gtin","arguments":{"code":"4006381333931"}}}'
```

→ `{"valid": true, "type": "ean13", ...}` (reply is one SSE `data:` line — see [examples](examples/quickstart.md)).

## Docs

- [examples/quickstart.md](examples/quickstart.md) — every call shape: list tools, render, decode
- [examples/clients.md](examples/clients.md) — connect from Claude Code / Desktop / Cursor / any MCP client
- [clients/python.py](clients/python.py) — minimal Python client (stdlib only)

## Status / support

Open an [issue](../../issues) for: a symbology you need, size limits
(images are accepted up to ~4 MB base64), uptime questions.