Crontab Server

An MCP server for exploring, explaining, and managing crontab entries. Works with Claude Desktop, Claude Code, and any MCP client.

Standout features: Explain cron expressions in plain English and calculate upcoming execution times — no more guessing what */15 9-17 * * 1-5 means.

Quick Start

Claude Desktop

Add to your Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "crontab": {
      "command": "uvx",
      "args": ["mcp-crontab-server"]
    }
  }
}

Claude Code

claude mcp add crontab -- uvx mcp-crontab-server

Install from source

git clone https://github.com/jalloway/mcp-crontab-server.git
cd mcp-crontab-server
pip install -e .
mcp-crontab-server

Tools

Example Conversations

"What does this cron expression mean?"

explain_cron_expression("*/15 9-17 * * 1-5")

Every 15 minutes, from 9:00 AM through 5:59 PM, Monday through Friday

"When will this job run next?"

next_runs("0 2 * * 0", count=3)

Next 3 runs for '0 2 * * 0':

1. 2026-03-01 02:00:00 Sunday
2. 2026-03-08 02:00:00 Sunday
3. 2026-03-15 02:00:00 Sunday

"Is this valid?"

validate_cron_expression("60 * * * *")

Invalid: Value 60 out of range (0-59) in minute field

Development

pip install -e .

# Run with MCP inspector
fastmcp dev src/mcp_crontab_server/server.py

# Run directly (stdio transport, default)
mcp-crontab-server

# Run with SSE transport
mcp-crontab-server --transport sse

Requirements

• Python 3.10+
• Linux/macOS (uses crontab command)
• fastmcp>=2.0.0, croniter>=1.0.0