WillItPlug API and MCP server

The data behind WillItPlug is free to use, for apps and for AI agents. No key and no sign-up. In return, please credit WillItPlug with a link.

MCP server

Add it to ChatGPT, Claude or any MCP client as a remote server. Streamable HTTP, no authentication.

https://www.willitplug.com/mcp/

Published in the official MCP Registryunder com.willitplug/willitplug, verified against this domain. In MCP Apps-compatible assistants, check_trip opens a trip checker with the verdict, voltage guidance and a packing checklist.

check_trip(from, to) - do my plugs fit, do I need an adapter or converter, and what to pack.
country_plugs(country) - outlet and plug types, voltage and frequency for one country.
find_countries_by_outlet(type) - every country with outlets of one plug type.
plug_type(type) - what a plug type is: its standard, whether it is earthed, and which plugs its socket takes.

Countries are English names ("Japan") or ISO codes ("jp"). Plug types are IEC letters from A to O. Every tool is read-only and returns structured content with a declared output schema, plus the same answer as text.

Travel-power agent skill

Install the official skill in your coding assistant for trip checks, country lookups, voltage precautions and source citations. It uses the public tools and API above.

npx skills add https://www.willitplug.com --skill willitplug

Public agent integration on GitHubincludes the portable plugin manifest, MCP setup and a verification script. Read the skill, or discover it through theskill index. Country and trip pages also support Markdown: replace the trailing slash with.md, or request Accept: text/markdown. For example, United States to Japan in Markdown.

The official skill is also available on skills.sh.

Documentation MCP server

Search and read the official integration guides over MCP. Use this server to learn the API, and the product server above for country and trip lookups. Both are public and read-only.

https://www.willitplug.com/docs/mcp/

Tools: search_documentation(query) andread_documentation(id). Results include source URLs; the same documents are also exposed as MCP resources.Official documentation MCP Registry listing.

Content search and feeds

Search country information and developer guides with NLWeb v0.55. Results come from the published content, with no generated answers or stored sessions.

curl https://www.willitplug.com/ask/ -H 'Content-Type: application/json' \
  -d '{"query":{"text":"Japan voltage"},"prefer":{"mode":"list"}}'

Request prefer.streaming: true for SSE. For bulk retrieval, the country feedcontains schema.org JSON Lines records with the available source citations. It is indexed byschemamap.xml and advertised in robots.txt. See the publisher verification procedure for the resource catalog's identity claims.

Smaller API responses and request limits

Country lists are complete by default. Add ?limit=25 to/api/v1/countries.json and follow links.nextuntil it is null. Page sizes range from 1 to 100. Filter countries withoutlet=G, or connector standards with/api/v1/plugs.json?type=G.

The REST API allows approximately 300 requests per minute per client IP at each Cloudflare location. The response advertises this through RateLimit-Limit andRateLimit-Policy. On HTTP 429, wait forRetry-After: 60 before retrying. Cache and reuse country data. Invalid query parameters return a typed HTTP 400 problem.

WillItPlug SDK and CLI

The official JavaScript client and command-line tool. Node.js 22 or later, no API key. Install from npm:

npx willitplug-sdk trip us jp
npx willitplug-sdk country it
npm install willitplug-sdk

import { WillItPlug } from "willitplug-sdk";
const trip = await new WillItPlug().trip("us", "jp");
console.log(trip.adapterNeeded, trip.checklist, trip.url);

willitplug-sdk on npm, ordownload version 1.0.0 directly. The CLI accepts ISO country codes and prints JSON. Commands: trip,country, countries and plugs. The SDK includes TypeScript declarations and supports request cancellation with an AbortSignal. MIT-licensed code; please credit WillItPlug when using its data.

JSON API

Static JSON on a CDN, CORS enabled. Countries use lowercase ISO 3166-1 alpha-2 codes.

/api/v1/countries.json
Every country: plugs, outlets, voltage, frequency and page URL.
/api/v1/countries/jp.json
One country by ISO code, with notes, sources and when it was last checked.
/api/v1/trips/us/jp.json
A trip: which plugs fit, whether you need an adapter or converter, and a packing checklist.
/api/v1/plugs.json
The plug and socket standards and which plugs each socket takes.
/api/v1/openapi.json
OpenAPI 3.1 description of all of the above.

curl https://www.willitplug.com/api/v1/trips/us/jp.json

Every response includes a credit object and the URL of the matching page. Also see llms.txt and the API catalog.

Errors

Errors are JSON too, as RFC 9457 problems with the content type application/problem+json. Branch on code: not_found for a path that doesn't exist, unknown_trip for a trip between unknown or identical countries. detail says how to fix the request.

{
  "type": "https://www.willitplug.com/developers/#errors",
  "title": "No such API resource",
  "status": 404,
  "code": "not_found",
  "detail": "Check the path against /api/v1/openapi.json."
}

Versioning and deprecation

The version is in the path. Within /api/v1/ fields are only added, never renamed or removed, so ignore fields you don't know. A breaking change gets a new path, and the old one keeps working for at least six months, answering with Deprecation and Sunset headers from the day its end date is set. No version is deprecated today.

Testing

There is no sandbox because there is nothing to break: the API and the MCP server are read-only, hold no accounts and change no data, so test against the live endpoints.