OnionLens.Field Guide MCP tools

Check an
onion address.

Verify the v3 format, version byte and SHA3-256 checksum. The checker never connects to the address. A passing checksum says nothing about trust or availability.

Paste the complete hostname or URL, including .onion.

Submitted form text is excluded from research logs.

Awaiting input

A small check.
A useful first step.

Catch a mistyped hostname before debugging your Tor connection.

Use it from your tools.

curl -sS https://onionlens.org/api/v1/onion/validate \
  -H 'Content-Type: application/json' \
  --data '{"address":"pjzhmrhqlmjvhb5eeqmgnil7oztrbqkt45hay4zsvj5e6dblnfezopyd.onion"}'

Also available through validate_onion_address on the MCP endpoint. Encoding follows the Tor v3 address specification.