MyBestSim in ChatGPT and Claude

Ask ChatGPT or Claude which travel eSIM to buy, and the answer comes from the MyBestSim comparator: current prices, data allowance, validity, and a link to compare the plans on our site.

What the app does

MyBestSim compares travel eSIM plans from many providers. The app gives your assistant access to that comparator. It only reads our data: there is no account, no sign-in, and nothing is bought in the chat. To buy, you open our comparison page, then the provider’s site.

The four tools

Search plans for a destination (search_esim_plans): finds plans for one country or region that fit your trip length, data need, budget and features (5G, hotspot, calls, SMS). If you do not say how long you travel or how much data you need, it assumes a 7-day trip with standard use and says so. Give the real figures to refine the answer.
Plan a trip across several countries (plan_trip_esim): for up to 8 stops in travel order, compares one eSIM for the whole trip with one eSIM per country, at real prices.
Destination overview (get_destination_overview): how many plans and providers we list, typical prices (the median price of common plan sizes, such as 1 GB for 7 days or 10 GB for 30 days, and the median price per GB, over all the plans on the page), the cheapest plan, the best price per GB and the cheapest unlimited plan.
Plan details (get_esim_plan): coverage, validity, features and price of a plan from a previous answer.

How to add it

App address: https://mcp.mybestsim.com/mcp (no sign-in).

ChatGPT

From the directory: once MyBestSim is listed in ChatGPT’s app directory, search for “MyBestSim” there and connect it.
By address: if your ChatGPT plan allows custom MCP servers (developer mode), add a custom server with the address above and no authentication. Menu names change from time to time: OpenAI’s help centre has the current steps.

Claude

Open Customize › Connectors (Settings › Connectors in some versions).
Select Add, then Add custom connector.
Name it MyBestSim, paste the address above, and choose no sign-in.

On the Free plan, Claude allows one custom connector. On Team and Enterprise plans, an owner first adds it in Organization settings › Connectors.

Then ask your question as usual. The assistant decides when to use MyBestSim. You can also ask it to by name.

Questions to try

“What is the cheapest eSIM for 10 days in Japan with at least 10 GB?”
“I’m visiting Thailand, Vietnam and Cambodia over three weeks. Is one eSIM cheaper than one per country?”
“How much does a travel eSIM cost in the United States?”

Limits

Up to 10 plans per answer, and at most 2 per provider. For the full list, open the comparison page linked in the answer.
Destinations: the countries and regions that have a comparison page on mybestsim.com. Well-known cities are matched to their country.
Prices come from our catalogue, which we update regularly. They are shown in your currency, the one our comparison page uses for your language (euros in French, German or Spanish, US dollars in English), and the assistant can ask for another one: the price in the conversation is the price on the page the link opens. Providers can change their prices at any time: check the price on the provider’s site before you buy.
For unlimited plans, the provider’s fair-use limits are not shown in the app. Check them on the provider’s site.
Links open our comparison page in your language when it exists, otherwise in English.
To keep the service available, the number of requests per address is limited. A normal conversation stays well below the limit. If you get a “too many requests” message, wait a few minutes.
The assistant words the answer itself and can make mistakes. Our comparison page is the reference.

How MyBestSim earns money

MyBestSim is free. When you buy an eSIM after clicking a link on our site, the provider may pay us a commission, at no extra cost to you. The app only shows plans listed on our comparison page for the destination, the page its links open. It ranks them only by your request (price, value for your data need, data or validity): no paid placement changes their order. Which plans a page lists follows the rules of our comparator: near-identical plans from one provider may be shown once, and when plans from different providers are comparable, the page may keep only the one from a provider that earns us more, sometimes at a higher price. A plan that a provider pays us to feature is never removed by these rules, and it gets no better rank in the app.

Privacy

The app needs no account and does not see your conversation. It receives the search parameters, technical details of the request, and the IP address of the caller (normally an OpenAI or Anthropic server), which is recorded only as a fingerprint that changes every day. The usage log is deleted after 3 months. Details: Privacy policy, section 10.

Help and contact

A question, a wrong answer, a missing destination? Write to us via the contact page or at [email protected].