@mcp-india/gst-india

Offline MCP server for Indian GST — validate GSTINs, calculate taxes, and look up HSN/SAC codes through AI assistants like Claude. No API keys required.

Installation

npx -y @mcp-india/gst-india

No configuration needed. Works instantly.

Configuration

Add to your Claude Desktop claude_desktop_config.json:

{
  "mcpServers": {
    "gst-india": {
      "command": "npx",
      "args": ["-y", "@mcp-india/gst-india"]
    }
  }
}

That's it — no environment variables needed.

Available Tools

Validation

| Tool | Description | |------|-------------| | gst_validate_gstin | Validate GSTIN format, check digit, and extract state/PAN/entity info | | gst_validate_invoice_number | Validate GST invoice number format (max 16 chars, Rule 46) | | gst_get_state_info | Get state/UT name from a 2-digit code or GSTIN |

Calculation

| Tool | Description | |------|-------------| | gst_calculate_tax | Calculate CGST/SGST/IGST breakdown for a given amount and rate | | gst_determine_supply_type | Determine intra-state or inter-state from two GSTINs | | gst_reverse_calculate | Extract base amount from a GST-inclusive price |

HSN & Rates

| Tool | Description | |------|-------------| | gst_search_hsn | Search 500+ HSN and 120+ SAC codes by keyword or code number | | gst_get_hsn_details | Get full details and GST rate for a specific HSN/SAC code | | gst_list_rate_slabs | List all GST rate slabs (0%, 5%, 12%, 18%, 28%) with examples |

Example Conversations

Validate a GSTIN:

"Is GSTIN 27AABCU9603R1ZN valid? What state and PAN does it belong to?"

Calculate GST:

"Calculate 18% GST on Rs 50,000 for an intra-state sale in Maharashtra."

Reverse-calculate from inclusive price:

"I paid Rs 11,800 including GST at 18%. What was the base price?"

Look up HSN code:

"What's the HSN code and GST rate for laptops?"

Check supply type:

"Is a sale from Maharashtra (27) to Karnataka (29) intra-state or inter-state?"

Bundled Data

This package includes curated, offline datasets:

• 500+ HSN codes covering goods across all major chapters (food, textiles, electronics, metals, vehicles, etc.)
• 120+ SAC codes covering services (IT, finance, transport, construction, consulting, etc.)
• 38 state/UT codes with names and state/UT classification
• 6 GST rate slabs (0%, 5%, 12%, 18%, 28%, and special 3% for precious metals)

All data is bundled into the package at build time. No network requests are made.

Troubleshooting

Server fails to start Ensure you have Node.js 20+ installed. Run node --version to check.

HSN/SAC search returns no results Try a broader keyword (e.g., "computer" instead of "Dell laptop"). The search matches against official code descriptions.

Rate information seems outdated GST rates change when the GST Council issues new notifications (2-4 times per year). Please open an issue if you notice outdated rates.

License

MIT