mcp-registry/io.github.hebcal/hebcal · v1.14.4
As of 2026-10-17 07:38 UTC, the Hebcal MCP server is up with a Glimind reliability score of 88/100 (grade B). Over the last 30 days it answered 99.9% of Glimind's liveness checks. It had 4 outages in 90 days, with a median recovery of 7 minutes.
Model Context Protocol extension for Hebrew calendar
Claude Code
claude mcp add --transport http hebcal-mcp-server https://www.hebcal.com/mcp
Claude Desktop · Windsurf · Cline (mcpServers JSON)
{
"mcpServers": {
"hebcal-mcp-server": {
"type": "http",
"url": "https://www.hebcal.com/mcp"
}
}
}
Third-party server, listed as discovered. Review its source before installing.
7 of 7 tool(s) carry no readOnlyHint/destructiveHint annotations.
Annotate read-only tools with {"readOnlyHint": true}. Agents and gateways can then run them without a confirmation prompt, and route around destructive ones.
Handshake + tools/list takes ~1,701 ms.
Serve tools/list from memory, keep the process warm, and host close to your users. Every new agent session pays this before its first call.
No tool declares an outputSchema.
Declare outputSchema and return structuredContent (MCP 2025-06-18+). Agents can then parse results without guessing, and chain tools reliably.
Paste-ready definitions with the problems above fixed. Changes marked verify need a human look. All of them as JSON: /v1/readiness/mcp-registry%2Fio.github.hebcal%2Fhebcal/fixes
{
"name": "convert-gregorian-to-hebrew",
"description": "Converts a Gregorian (civil) date to a Hebrew date (Jewish calendar)",
"inputSchema": {
"type": "object",
"required": [
"date"
],
"properties": {
"date": {
"type": "string",
"description": "Gregorian date (in yyyy-MM-dd format) to convert"
}
},
"additionalProperties": false
},
"annotations": {
"readOnlyHint": true
}
}{
"name": "convert-hebrew-to-gregorian",
"description": "Converts a Hebrew date to a Gregorian (civil) date",
"inputSchema": {
"type": "object",
"required": [
"day",
"month",
"year"
],
"properties": {
"day": {
"type": "integer",
"description": "Hebrew day of month"
},
"year": {
"type": "integer",
"description": "Hebrew year"
},
"month": {
"type": "string",
"description": "Hebrew month name transliterated, like Elul or Tishrei"
}
},
"additionalProperties": false
},
"annotations": {
"readOnlyHint": true
}
}Get an email or webhook when this server's readiness drops by 10+ points, tool-poisoning text appears, or a tool breaks:
curl -X POST https://glimind.com/v1/subscriptions -H 'content-type: application/json' -d '{"tools":["mcp-registry/io.github.hebcal/hebcal"],"email":"[email protected]"}'Agents: watch_tool({"toolId": "mcp-registry/io.github.hebcal/hebcal"}) over MCP.
shabbat-times ~210 tokensconvert-hebrew-to-gregorian ~119 tokensyahrzeit ~119 tokenstorah-portion ~107 tokensconvert-gregorian-to-hebrew ~86 tokensStatic checks of the advertised tools/list (schema, descriptions, annotations, tool-poisoning patterns, names, size) plus observed protocol, uptime, latency and contract changes. Read-only: no tool is ever called. Weights: schema 15, docs 20, safety 15, efficiency 15, compatibility 15, protocol 5, reliability 10, stability 5. Token counts are estimates (~3.6 characters per token).
Operator? Fix these, then re-check live. Embed the readiness badge:
[](https://glimind.com/server/mcp-registry%2Fio.github.hebcal%2Fhebcal?ref=badge)
<a href="https://glimind.com/server/mcp-registry%2Fio.github.hebcal%2Fhebcal?ref=badge"><img src="https://glimind.com/v1/readiness/badge/mcp-registry%2Fio.github.hebcal%2Fhebcal.svg" alt="MCP agent-readiness"></a>
.. image:: https://glimind.com/v1/readiness/badge/mcp-registry%2Fio.github.hebcal%2Fhebcal.svg :target: https://glimind.com/server/mcp-registry%2Fio.github.hebcal%2Fhebcal?ref=badge :alt: MCP agent-readiness
Glimind records every version of this server's tool definitions in a signed, append-only transparency log. Current manifest sha256:0239783e5bb862e4…, first seen 2026-10-17, included at leaf 4565 of 17,132. Version history · verify what your client received.
Compare: most reliable data servers · most reliable knowledge servers
Glimind tells agents whether a server is up right now and how to call it, then fails over to a live alternative when it isn't.
Claude Code
claude mcp add --transport http glimind https://glimind.com/mcp
Claude Desktop · Windsurf · Cline (mcpServers JSON)
{
"mcpServers": {
"glimind": {
"type": "http",
"url": "https://glimind.com/mcp"
}
}
}
As of 2026-10-17 07:38 UTC, the Hebcal MCP server is up with a Glimind reliability score of 88/100 (grade B). Over the last 30 days it answered 99.9% of Glimind's liveness checks. It had 4 outages in 90 days, with a median recovery of 7 minutes.
Hebcal MCP server advertises 12 tools, including convert-gregorian-to-hebrew, convert-hebrew-to-gregorian, convertDate, daf-yomi, getHolidays.
Point your MCP client at this streamable-http endpoint: https://www.hebcal.com/mcp
Glimind scanned all 7 tool definitions for tool-poisoning patterns — hidden or invisible characters, instructions that override the model, concealment from the user, requests to read credential or MCP config files, conversation exfiltration and cross-tool shadowing — and found none. This checks what the server tells the model, not what its code does; review the source before granting access to sensitive data.
Status page: 90-day uptime, every outage and how long it lasted.
Claim this listing to get the Verified operator marker, a remediation checklist and owner analytics, or embed the live badge from any of the tool pages above. Maintainers: alerts, deploy attestation and monthly reports.
Status is an automated estimate from Glimind's liveness checks (handshake and tool listing only; no tool is ever called) and may lag or differ from your network. Glimind is not affiliated with this server or its operator. Operator? Request a correction or opt out at https://glimind.com/opt-out.