Ba-Zi.ai Chinese Astrology MCP server

Chinese Astrology Skill 🔮

The most comprehensive Chinese astrology AI skill — 4 tools covering BaZi (Four Pillars of Destiny), bone weight fortune telling, and Chinese almanac. Available as an Agent Skill (SKILL.md) and MCP server.

Built by Ba-Zi.ai — Free AI-powered BaZi calculator and Chinese astrology platform.

Features

What makes this different?

• Bone Weight Fortune (秤骨算命) — The only MCP/Skill that includes Yuan Tiangang's 1,300-year-old bone weight calculation with all 52 classical poems and modern interpretations
• Bilingual descriptions — All tool descriptions in both English and Chinese
• Accurate calculations — Powered by tyme4ts, the most precise Chinese calendar library

Quick Start

Claude Desktop / Claude Code

Add to your MCP config:

{
  "mcpServers": {
    "chinese-astrology": {
      "command": "npx",
      "args": ["-y", "chinese-astrology-skill"]
    }
  }
}

Stdio Transport

npx chinese-astrology-skill

HTTP Transport

git clone https://github.com/xlw-pro/chinese-astrology-skill.git
cd chinese-astrology-skill
npm install
npm start
# Server runs at http://localhost:3000/mcp

Tools

1. getBaziChart — BaZi Chart Calculation (八字排盘)

Calculate a complete Four Pillars of Destiny chart from birth datetime.

Input:

{
  "solarDatetime": "2000-01-15T12:00:00+08:00",
  "gender": 1
}

Returns: Complete BaZi chart including:

• Four Pillars (年柱/月柱/日柱/时柱) with Heavenly Stems & Earthly Branches
• Five Elements (五行) for each position
• Ten Gods (十神) relationships
• Hidden Stems (藏干) — main, middle, and residual qi
• Nayin (纳音), Void (空亡), Terrain (星运)
• Decade Fortune (大运) — 10 periods with start ages
• Gods & Spirits (神煞) for all four pillars
• Branch Relations (刑冲合会) — clashes, combinations, penalties

2. findBirthDates — Reverse BaZi Lookup (八字反查)

Find all possible birth dates (from 1700 to present) that match a given BaZi string.

Input:

{
  "bazi": "戊寅 己未 己卯 辛未"
}

Returns: Array of matching solar datetimes.

3. getAlmanac — Chinese Almanac (黄历)

Get Chinese almanac information for any date.

Input:

{
  "solarDatetime": "2026-04-06T00:00:00+08:00"
}

Returns: Lunar date, zodiac, Nayin, solar terms, 28 mansions, Peng Zu taboos, directional gods (Joy/Yang Noble/Yin Noble/Mascot/Wealth), auspicious & inauspicious activities, clash info.

4. calculateBoneWeight — Bone Weight Fortune (秤骨算命) ⭐

Calculate bone weight fortune using Yuan Tiangang's ancient Tang Dynasty method (c. 600 CE).

Input:

{
  "solarDatetime": "1990-06-15T14:00:00+08:00"
}

Returns:

{
  "totalWeight": 4.8,
  "unit": "两 (liǎng)",
  "percentile": 54,
  "breakdown": {
    "year": { "ganzhi": "庚午", "weight": 0.9 },
    "month": { "lunarMonth": 5, "weight": 0.5 },
    "day": { "lunarDay": 23, "weight": 0.8 },
    "hour": { "earthBranch": "未", "weight": 0.8 }
  },
  "poem": "初年运道未曾亨...",
  "interpretation": "Late success through independence..."
}

Weight ranges from 2.1 to 7.2 liǎng across 52 destiny types. Learn more about bone weight fortune →

Use Cases

Shortened. The full README is on GitHub.