Yaktool precision tools for product data

Yaktool for AI agents

Agents keep rewriting the same ad-hoc validators — and each one misses the edge cases. The Yaktool MCP servers put all 112 checks inside your agent: the same rule engine as this site, with every check numbered, severity-graded and backed by an official source.

8 focused servers

The tools ship as separate npm packages, split by what they carry — install any or all. Nobody downloads image codecs to validate a barcode.

yaktool-mcp

Validation suite — 73 tools. GTIN/EAN/UPC, product feeds, Shopify CSV, GS1, ISBN, VIN, IBAN, Peppol, XRechnung and more. Pure rule code, no wasm — a small, fast install. 

claude mcp add yaktool -- npx -y yaktool-mcp

yaktool-image-mcp

Image tools — 2 tools. Compress PNG/JPEG on your machine (smart visually-guarded lossy, or true lossless), with WebP/AVIF output. Ships the wasm codecs. Same engine as the browser compressor. 

claude mcp add yaktool-image -- npx -y yaktool-image-mcp

yaktool-labels-mcp

Label tools — 3 tools. Print-ready Amazon FBA (FNSKU) label PDFs at exact physical size — 30-up sheets, A4 or thermal rolls, bars on the printer dot grid, calibration page included. Same engine as the browser generator. 

claude mcp add yaktool-labels -- npx -y yaktool-labels-mcp

yaktool-pdf-mcp

PDF tools — 12 tools. Merge, split, compress, unlock and reorganise PDFs with a structure diagnosis first: truncation, encryption and damaged cross-references come back as numbered findings, and bad files are skipped with their diagnosis — never silently. Same engine as the browser tools. 

claude mcp add yaktool-pdf -- npx -y yaktool-pdf-mcp

yaktool-store-mcp

Store CSV tools — 2 tools. Forecast what a WooCommerce import will actually do — which rows create, which are silently skipped, which columns never map — and convert a Shopify export into a WooCommerce import without losing variants or reversing sale prices. Same engine as the browser validator. 

claude mcp add yaktool-store -- npx -y yaktool-store-mcp

yaktool-compliance-mcp

Compliance tools — 9 tools. GPSR listings against Article 19, EUDR plot geolocation before a Due Diligence Statement, FDA nutrition rounding, and EU fragrance allergen thresholds. Every rule cites its source — and says so when it is our reading rather than regulation text. Same engine as the browser checkers. 

claude mcp add yaktool-compliance -- npx -y yaktool-compliance-mcp

yaktool-gs1-mcp

GS1 tools — 7 tools. Build GS1 element strings with FNC1 placement handled, generate a GS1 DataMatrix (ECC200), and validate the eight GS1 identification keys beyond GTIN — including the GMN check character pair. Same engine as the browser builder. 

claude mcp add yaktool-gs1 -- npx -y yaktool-gs1-mcp

yaktool-invoice-mcp

E-invoice tools — 4 tools. Check an invoice against the mandatory fields of EN 16931 with the arithmetic rules quoted verbatim, and look up the four code lists an invoice is judged by — including the rules each VAT category code brings into force. Same engine as the browser checker. 

claude mcp add yaktool-invoice -- npx -y yaktool-invoice-mcp

Claude Desktop

Add to claude_desktop_config.json (keep only the servers you want):

{
  "mcpServers": {
    "yaktool": { "command": "npx", "args": ["-y", "yaktool-mcp"] },
    "yaktool-image": { "command": "npx", "args": ["-y", "yaktool-image-mcp"] },
    "yaktool-labels": { "command": "npx", "args": ["-y", "yaktool-labels-mcp"] },
    "yaktool-pdf": { "command": "npx", "args": ["-y", "yaktool-pdf-mcp"] },
    "yaktool-store": { "command": "npx", "args": ["-y", "yaktool-store-mcp"] },
    "yaktool-compliance": { "command": "npx", "args": ["-y", "yaktool-compliance-mcp"] },
    "yaktool-gs1": { "command": "npx", "args": ["-y", "yaktool-gs1-mcp"] },
    "yaktool-invoice": { "command": "npx", "args": ["-y", "yaktool-invoice-mcp"] }
  }
}

Cursor and other MCP clients

Any stdio-capable MCP client works — the command is npx -y <package> and it requires Node.js ≥ 20. Packages on npm: yaktool-mcp · yaktool-image-mcp · yaktool-labels-mcp · yaktool-pdf-mcp · yaktool-store-mcp · yaktool-compliance-mcp · yaktool-gs1-mcp · yaktool-invoice-mcp

Why not just let the agent write a validator?

Validation suite yaktool-mcp

Every tool mirrors a check you can also run in the browser — same engine, same rules, same results.

Image tools yaktool-image-mcp

Label tools yaktool-labels-mcp

PDF tools yaktool-pdf-mcp

Store CSV tools yaktool-store-mcp

Compliance tools yaktool-compliance-mcp

GS1 tools yaktool-gs1-mcp

E-invoice tools yaktool-invoice-mcp