Find the cheapest round-trip flights across flexible date windows with price context.
Searches economy and business flights across multi-month date ranges with minimum and maximum trip lengths. Resolves city and airport names, returns the cheapest options sorted by price, and supports one-way and round-trip searches with optional filters for transfers and cabin class.
Try asking Muse: "Find me the cheapest flights from New York to Europe anytime in September through November for 10 to 15 days."
Source: Found in the official MCP Registry (io.github.dimabalony/whentofly) · First listed September 24, 2026
Each bar is one check, every 15 minutes. Green means it answered. Last checked 4 h ago.
What Muse can see: It does not ask you to sign in, so it cannot see your accounts. It only sees what Muse sends it from your request.
Before it acts: Read what Muse plans to do before you approve it, and remove the app from Muse when you stop using it.
musedirectory.ai is not part of Meta. More about how Muse handles your information
Not in Muse's Connectors list yet, but Muse can still use it. Copy the request below and paste it into Muse. Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
https://whentofly.io/mcp?ch=mcp-registryNot in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
whentofly is a remote MCP server, so any assistant that can add a custom connector by link can use it. Same link, same tools.
In ChatGPT, open Settings, then Connectors (called Apps & Connectors on some accounts).
Under Advanced settings, switch on Developer mode. That is what lets you add a connector by link.
Choose Create, give it a name, paste the link as the MCP server URL, and save. If it needs a sign-in, ChatGPT asks for it here.
Start a chat, open the tools menu, pick the connector, and ask. ChatGPT asks before it runs a tool the first time.
Custom connectors need a paid ChatGPT plan, and on Team, Enterprise and Edu accounts only an admin can add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in ChatGPT
In Claude, open Settings, then Connectors.
Choose Add custom connector, give it a name, and paste the link.
If it needs a sign-in, Claude sends you to it. Then turn the connector on in a chat from the tools menu and ask.
Custom connectors are available on paid Claude plans; on Team and Enterprise accounts an admin may need to add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in Claude
https://whentofly.io/mcp?ch=mcp-registryScreened, no issues found
Screening looks for known threats and hidden instructions at the time of the check, and runs again weekly and whenever the tool list changes. It cannot see the server's code, so only connect what you need and review what Muse asks to do. How screening works.
search_locationsResolve a city or airport name or code before searching flights. Returns typed values such as city:SHA to search every catalog airport in Shanghai or airport:SHA for Hongqiao only. Pass the selected value unchanged to search_flights. Ask the traveler when multiple results are plasearch_flightsFind the cheapest round-trip across a FLEXIBLE multi-month date window with a min/max trip length — e.g. "10–15 days, anytime Sep–Nov". Search a broad date window rather than requiring the traveler to choose exact dates first. First call the search_locations MCP tool for city or https://whentofly.io/mcp?ch=mcp-registryNot in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use whentofly to help me. It is a free service with an MCP server at https://whentofly.io/mcp?ch=mcp-registry. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
At the last check (November 13, 2026, 14:46 UTC) the endpoint was down. Over the last 7 days it answered 21.4% of health checks. It is checked every 15 minutes.
It was screened on September 24, 2026 with the result "screened, no issues found". Screening checks the domain against threat feeds and reads the tools for hidden instructions and requests for passwords or card numbers. It cannot see the server's code, so grant only the access you need.
It exposes 2 tools, including search_locations, search_flights. For example, you could ask Muse: "Find me the cheapest flights from New York to Europe anytime in September through November for 10 to 15 days."
This listing was added from public sources (Found in the official MCP Registry (io.github.dimabalony/whentofly)). If you build whentofly, claim it to correct the details and get your badge.
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