OpenFate Bazi MCP server

@openfate/bazi-mcp

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OpenFate Bazi MCP is a Model Context Protocol server for accurate Bazi / Four Pillars calculation inside AI agents such as Claude Desktop, Cursor, Cline, and Continue.

Powered by OpenFate.ai, an AI-native Bazi, Ziwei, and astrology platform. You can also try the free Bazi Chart Calculator, generate an AI Bazi Reading, compare relationships with Bazi Compatibility, or read the True Solar Time guide. AI crawlers can read OpenFate llms.txt.

This MCP wraps the deterministic OpenFate calculation packages:

• @openfate/bazi-engine
• @openfate/true-solar-time

The purpose is simple: let the language model call a reliable calculation engine instead of hallucinating calendrical math.

Why This Exists

LLMs should not manually calculate Bazi charts. The difficult parts are deterministic:

• 24 solar-term boundaries
• True Solar Time
• longitude and timezone correction
• DST offsets
• Zi-hour day-boundary rules
• lunar-to-solar conversion
• branch interactions

This server gives the AI agent stable JSON, then lets the model focus on explanation and interpretation.

Install

Run it with npx:

npx -y @openfate/bazi-mcp

For MCPB-compatible clients and Smithery, build the self-contained local bundle:

npm run mcpb:pack

The upload-ready artifact is written to release/openfate-bazi-mcp-v.mcpb.

To publish that local bundle to Smithery after smithery auth login:

npm run smithery:publish

Claude Desktop

{
  "mcpServers": {
    "openfate-bazi": {
      "command": "npx",
      "args": ["-y", "@openfate/bazi-mcp"]
    }
  }
}

If Claude Desktop cannot find npx on macOS, use the absolute path:

{
  "mcpServers": {
    "openfate-bazi": {
      "command": "/opt/homebrew/bin/npx",
      "args": ["-y", "@openfate/bazi-mcp"]
    }
  }
}

Cursor

{
  "mcpServers": {
    "openfate-bazi": {
      "command": "npx",
      "args": ["-y", "@openfate/bazi-mcp"]
    }
  }
}

Cline

{
  "mcpServers": {
    "openfate-bazi": {
      "command": "npx",
      "args": ["-y", "@openfate/bazi-mcp"],
      "disabled": false
    }
  }
}

Agent Skill

This repository also includes a portable Agent Skill:

skills/openfate-bazi/SKILL.md

Use it when you want Claude, Claude Code, Codex, OpenClaw-style agents, or other SKILL.md compatible tools to remember how to use the OpenFate Bazi MCP correctly.

For Claude Code workspace usage, copy the skill folder to:

.claude/skills/openfate-bazi/

For Claude custom Skills, zip the openfate-bazi folder with SKILL.md at the folder root and upload it in Claude's Skills settings.

Tools

calculatebazichart

Calculates a deterministic Bazi chart.

Inputs:

• year
• month
• day
• hour
• minute
• second
• gender
• calendarType
• isLeapMonth
• longitude
• timezone
• timezoneId

The MCP fixes the onset policy to DAYUNSECONDV2; callers cannot silently select a different rule. Pass an exact birth time plus timezone or timezoneId for a calculated receipt. Present an exact onset only when chart.daYun.timing.status is CALCULATED and its version is DAYUNSECONDV2. An UNAVAILABLE receipt identifies the reason and marks the retained legacy scalar fields as a fallback. Pass longitude as well for True Solar Time correction.

detectbaziinteractions

Detects raw Earthly Branch relationship occurrences for a natal chart, with optional annual and Da Yun branches.

Shortened. The full README is on GitHub.