Hebcal

7 tools. 6 can modify or destroy data without limits.

6 write tools that can modify data. Rate limits recommended.

Last updated:

6 can modify or destroy data
1 read-only
7 tools total

6 Hebcal tools can modify or destroy data, with no limits today. PolicyLayer puts allow, deny, and rate-limit rules on every call. Live in minutes.

SECURE HEBCAL →

Free to start. No card required.

Read (1) Write / Execute (6) Destructive / Financial (0)
784 tokens of tool definitions, loaded on every request
0.4% of a 200k context window
216 heaviest tool: shabbat-times

Write operations (convert-gregorian-to-hebrew, convert-hebrew-to-gregorian, daf-yomi) modify state. Without rate limits, an agent can make hundreds of changes in seconds — faster than any human can review or revert.

Rate limit write operations
{
  "convert-gregorian-to-hebrew": {
    "limits": [
      {
        "counter": "convert-gregorian-to-hebrew_per_hour",
        "window": "hour",
        "max": 30,
        "scope": "grant"
      }
    ]
  }
}

Prevents bulk unintended modifications from agents caught in loops.

Cap read operations
{
  "jewish-holidays-year": {
    "limits": [
      {
        "counter": "jewish-holidays-year_per_minute",
        "window": "minute",
        "max": 60,
        "scope": "grant"
      }
    ]
  }
}

Controls API costs and prevents retry loops from exhausting upstream rate limits.

Get this policy live on your own Hebcal server in minutes. Tune the limits to your setup; PolicyLayer enforces it on every call.

ENFORCE ON MY HEBCAL →
How do I prevent bulk modifications through Hebcal? +

The Hebcal server has 6 write tools including convert-gregorian-to-hebrew, convert-hebrew-to-gregorian, daf-yomi. Set a rate limit in your policy -- for example, 10 calls per hour prevents an agent from making more than 10 modifications per hour. PolicyLayer enforces this at the gateway, before calls reach Hebcal.

How many tools does the Hebcal MCP server expose? +

7 tools across 2 categories: Read, Write. 1 are read-only. 6 can modify, create, or delete data.

How do I enforce a policy on Hebcal? +

Register the Hebcal MCP server in PolicyLayer, apply the suggested rules above (adjust the limits to your use case), and point your AI client at the PolicyLayer proxy URL instead of the server directly. Your agents keep the same tools; PolicyLayer evaluates every call against policy before it executes. Nothing to install, live in minutes.

Enforce policy on every Hebcal tool call.

Deterministic rules across all 7 Hebcal tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

4,600+ MCP servers and 31,000+ tools scanned and risk-classified.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.