MCP for AI agents

The API includes a Model Context Protocol (MCP) server, so AI assistants and agents can look up NSN data directly.

Setting Value
URL https://api.nsnlookup.com/mcp
Transport Streamable HTTP
Authentication Sign in with your NSN Lookup account (OAuth, for Claude, ChatGPT and other apps), or an API key: Authorization: Bearer YOUR_KEY / X-Api-Key: YOUR_KEY
Access Read-only

MCP calls use the same API key (or the signed-in account's key), plan, per-minute allowance, monthly quota and daily NSN limit as REST calls. Discovery: /.well-known/mcp.json (server card) and /llms.txt.

Tools

Tool What it does Parameters
search_nsn Search NSNs by item name, NSN or exact part number query, optional fsc, optional page
find_nsn_by_part_number NSNs that list a manufacturer part number partNumber, optional cage
lookup_nsn Full record for one NSN nsn, optional include
lookup_cage Company for a CAGE code cage
search_cage Find companies by name name
lookup_fsc Federal Supply Class title and notes fsc
lookup_inc Item Name Code name and definition inc
check_export Export screening from DEMIL / DEMILI (screening aid, not a license determination) nsns (list)
get_weight_dims Weight and dimensions, lb/in and kg/mm (Developer plan and above) nsns
get_trade_codes Schedule B and HTS codes (Developer and above) nsns
check_repairable Repairability from the Air Force ERRC (Developer and above) nsns
get_photos Watermarked photo URLs on www.nsnlookup.com (Developer and above) nsns
check_stock, check_price, check_lead_time, submit_rfq Coming soon: answer "coming soon" with a link to shop.nsnlookup.com nsns / nsnOrPartNumber

Tools return the same JSON as the REST endpoints of version 19. Field meanings are in the data dictionary. include takes the same section names as GET /v19/nsn/{nsn}.

Connecting

Claude, ChatGPT and other apps (no API key)

Add a custom connector with the URL https://api.nsnlookup.com/mcp and leave the authentication settings at their defaults. The app opens an NSN Lookup sign-in page; sign in with your www.nsnlookup.com account and click Allow. Step-by-step guide with pictures: Use NSN Lookup in Claude or ChatGPT.

For app developers: OAuth 2.1 authorization code flow with PKCE (S256), public clients only, dynamic client registration at /oauth/register. Metadata: /.well-known/oauth-protected-resource/mcp and /.well-known/oauth-authorization-server. Access tokens last an hour; refresh tokens 90 days. Scope nsn.read.

Claude Code and other developer tools (API key)

Claude Code:

claude mcp add --transport http nsnlookup https://api.nsnlookup.com/mcp --header "Authorization: Bearer YOUR_KEY"

Generic MCP client configuration:

{
  "mcpServers": {
    "nsnlookup": {
      "type": "http",
      "url": "https://api.nsnlookup.com/mcp",
      "headers": { "Authorization": "Bearer YOUR_KEY" }
    }
  }
}

Any client that supports remote MCP servers over streamable HTTP with a custom header can connect the same way.

Notes