Flat Earth Science MCP Server

by flatearthscience Your server? Claim it

answering

Flat Earth Science is answering right now. Last checked 2 min ago. It exposes 8 tools. Last commit 12 Nov 2026.

Earth curvature, horizon, flight, Sun and daylight calculators plus tested flat-earth claims.

Uptime history 9 hours of history

9 hours agonow

100.0%

Uptime 24h

31 of 31 checks

Tools

read from the server

302 ms

Response time

average over 24h

Stars

last commit 12 Nov 2026

Nothing serious here today

Today is the operative word: we check Flat Earth Science every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 2 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add flatearthscience-org --transport http https://flatearthscience.org/api/mcp

Settings → Connectors → Add custom connector, then paste this address

https://flatearthscience.org/api/mcp

~/.codex/config.toml

[mcp_servers.flatearthscience-org]
url = "https://flatearthscience.org/api/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "flatearthscience-org": {
      "url": "https://flatearthscience.org/api/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "flatearthscience-org": {
      "type": "http",
      "url": "https://flatearthscience.org/api/mcp"
    }
  }
}

Available tools 8

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

compare

compare_flat_map_distance

Compares the distance between two cities on a north-polar flat-Earth map with their great-circle distance over a sphere. Returns both distances and the factor by which the map stretches or shrinks the pair.

compare_true_size

Shows how much a Mercator map distorts a country's area, from its real area and the latitude it is drawn at. Returns the real area, the area multiplier at the country's own latitude and at a chosen latitude, and the size it appears at each. Covers the nine countries and regions in the website's size table.

calculate

calculate_curvature

Calculates how much of a distant target the Earth's curvature hides, from the surface distance, the observer's eye height, the target's height and an assumed refraction coefficient. Returns the hidden and visible height, the tangent-plane drop, the horizon distance and dip, the maximum mutual sight-line range and the midpoint bulge on a smooth sphere of radius 6,371.0084 km.

claims

find_claims

Searches the website's tested claims and flat-earth investigations, or returns one by id. Each result gives the claim, the verdict, the key evidence and the link to its page; an empty query lists all of them.

daylight

get_daylight_hours

Calculates the length of daylight at a place on a date, with sunrise and sunset in UTC, for the UTC day from midnight to midnight. A place is one of the website's 20 cities or a latitude with an optional longitude.

flight

get_flight_distance

Calculates the great-circle distance between two places in kilometres, miles and nautical miles, with the initial and final compass bearings. Each end is one of the website's 20 cities or a latitude and longitude.

horizon

get_horizon_distance

Gives the distance to the horizon from an eye height above a smooth sphere, and how far a taller object such as a mast stays in straight sight. Returns the observer's horizon distance, the range added by the target height and the maximum shared sightline.

sun

get_sun_position

Calculates the Sun's altitude and compass bearing at a place, date and UTC time, with the shadow of a 1 m upright and the day's sunrise and sunset in UTC. A place is one of the website's 20 cities or a latitude and longitude; without a date and time the result is for the current moment.

Endpoints

URL	Transport	State	Latency	Checked
https://flatearthscience.org/api/mcp	streamable-http	answering	460 ms	2 min ago

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Flat Earth Science — questions

Answers built from our own checks of this server.

What can Flat Earth Science do?

It exposes 8 tools, read directly from the server on our last check. Among them: calculate_curvature, compare_flat_map_distance, compare_true_size, find_claims, get_daylight_hours, get_flight_distance and 2 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Flat Earth Science working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 31 of 31 checks got a reply (100.0%), average response time 302 ms. The bar chart above shows every period we have measured.

How do I connect Flat Earth Science?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Flat Earth Science need an API key?

No. Flat Earth Science completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 8 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is Flat Earth Science?

It answers our handshake in 302 ms on average, which is faster than 48% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

Is Flat Earth Science open source?

We cannot say either way: 0 stars on GitHub, but we could not determine the licence, and without one the code is not open source by default.