Calculator MCP Server is answering right now. Last checked 12 min ago. 301 installs a week from npm. It exposes 1 tools. Last commit 14 Sep 2026.
Evaluate, simplify, and differentiate mathematical expressions.
Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 22 August 2026. No other catalogue keeps this.
Today is the operative word: we check Calculator MCP Server every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.
Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 12 min ago.
claude mcp add calculator-mcp-server --transport http https://calculator.caseyjhand.com/mcp
{
"mcpServers": {
"calculator-mcp-server": {
"url": "https://calculator.caseyjhand.com/mcp"
}
}
}
[mcp_servers.calculator-mcp-server]
url = "https://calculator.caseyjhand.com/mcp"
{
"mcpServers": {
"calculator-mcp-server": {
"url": "https://calculator.caseyjhand.com/mcp"
}
}
}
{
"mcpServers": {
"calculator-mcp-server": {
"url": "https://calculator.caseyjhand.com/mcp"
}
}
}
This one needs environment variables set before it will start:
CALC_MAX_EXPRESSION_LENGTH (Maximum allowed expression string length.), CALC_EVALUATION_TIMEOUT_MS (Maximum evaluation time in milliseconds.), CALC_MAX_RESULT_LENGTH (Maximum result string length in characters.), MCP_HTTP_HOST (The hostname for the HTTP server.), MCP_HTTP_PORT (The port to run the HTTP server on.), MCP_HTTP_ENDPOINT_PATH (The endpoint path for the MCP server.), MCP_AUTH_MODE (Authentication mode to use: 'none', 'jwt', or 'oauth'.), MCP_LOG_LEVEL (Sets the minimum log level for output (e.g., 'debug', 'info', 'warning').).
The author declared them in the registry entry; get the values from the project itself.
Read directly from the server with tools/list, grouped by what they act on.
If a tool disappears, we record the date.
calculate
| URL | Transport | State | Latency | Checked |
|---|---|---|---|---|
| https://calculator.caseyjhand.com/mcp | streamable-http | answering | 208 ms | 12 min ago |
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Answers built from our own checks of this server.