# NSN Lookup API

> National Stock Number (NSN) / NATO Stock Number data from NSN Lookup (https://www.nsnlookup.com): the U.S. Federal Logistics Information System (FLIS) catalog with part numbers and CAGE codes, FSC and INC, export screening (DEMIL), weight and dimensions, Schedule B / HTS codes, repairability and photos.

Freshness: FLIS data as loaded by NSN Lookup; every NSN answer has a dataAsOf block. Fields NSN Lookup does not hold are left out and named in notHeld. Export screening is a screening aid, not a license determination. Terms: answers are for your own work; no bulk storage, resale or republishing; link each NSN to its www.nsnlookup.com page (links.www). The API is for looking up the NSNs you need: daily distinct-NSN and search limits, 25 results per page and 100 per search, and a scraping check stop catalog downloads.

## Access

- [MCP server](https://api.nsnlookup.com/mcp): Streamable HTTP. Claude, ChatGPT and other apps sign in with an NSN Lookup account (OAuth; no key needed); developer tools send an API key as Authorization: Bearer or X-Api-Key.
- [Use NSN Lookup in Claude or ChatGPT](https://www.nsnlookup.com/nsn-api/ai): no-code setup steps
- [MCP server card](https://api.nsnlookup.com/.well-known/mcp.json)
- [REST documentation](https://api.nsnlookup.com/docs): base URL https://api.nsnlookup.com/v19, header X-Api-Key.
- [Plans and free keys](https://www.nsnlookup.com/nsn-api/pricing)

## Plans

- Anonymous (no key): 10 requests/minute, 50 distinct NSNs looked up/day, 50 searches/day, 1 NSN(s) per batch
- Free: 10 requests/minute, 1,000 requests/month, 50 distinct NSNs looked up/day, 200 searches/day, 5 NSN(s) per batch
- Developer: 60 requests/minute, 50,000 requests/month, 2,500 distinct NSNs looked up/day, 2,000 searches/day, 25 NSN(s) per batch
- Business: 300 requests/minute, 500,000 requests/month, 25,000 distinct NSNs looked up/day, 20,000 searches/day, 100 NSN(s) per batch
- Enterprise: 600 requests/minute, 5,000,000 requests/month, 250,000 distinct NSNs looked up/day, 200,000 searches/day, 250 NSN(s) per batch
- Vendor: 60 requests/minute, 50,000 requests/month, 2,500 distinct NSNs looked up/day, 2,000 searches/day, 25 NSN(s) per batch

## MCP tools

- lookup_nsn: Look up an NSN
- search_nsn: Search NSNs
- find_nsn_by_part_number: Find NSNs by part number
- lookup_cage: Look up a CAGE code
- search_cage: Search companies by name
- lookup_fsc: Look up a Federal Supply Class
- lookup_inc: Look up an Item Name Code
- check_export: Export screening (DEMIL)
- get_weight_dims: Weight and dimensions
- get_trade_codes: Schedule B and HTS codes
- check_repairable: Repairable check (ERRC)
- get_photos: Item photos
- check_stock: Stock check (coming soon)
- check_price: Price check (coming soon)
- check_lead_time: Lead time check (coming soon)
- submit_rfq: Request a quote (coming soon)

## REST endpoints

- GET /v19/nsn/{nsn}?include=references,management,...: one NSN
- GET /v19/search?q=&fsc=: search by name, NSN or part number
- GET /v19/parts?partNumber=&cage=: NSNs for a part number
- GET /v19/cage/{code}, /v19/cage?q=, /v19/fsc/{code}, /v19/inc/{code}
- GET /v19/export/{nsn} ; POST /v19/export/batch {"nsns":[...]}: Export screening from DEMIL and DEMIL Integrity Code (screening aid, not a license determination)
- GET /v19/weight-dims/{nsn} ; POST /v19/weight-dims/batch {"nsns":[...]}: Packaged and unpackaged weight and dimensions (lb/in with kg/mm), cube, unit of issue
- GET /v19/trade-codes/{nsn} ; POST /v19/trade-codes/batch {"nsns":[...]}: Schedule B and HTS codes
- GET /v19/repairable/{nsn} ; POST /v19/repairable/batch {"nsns":[...]}: Repairability from the Air Force ERRC
- GET /v19/photos/{nsn} ; POST /v19/photos/batch {"nsns":[...]}: Photos taken by NSN Lookup (watermarked www.nsnlookup.com URLs)