Bazi MCP

What openfate-ai/bazi-mcp MCP server does

The openfate-ai/bazi-mcp MCP server exposes local Bazi and Four Pillars calculations through the Model Context Protocol. It is intended for agents that need consistent calendrical results, including solar and lunar calendar normalization, True Solar Time correction, Da Yun timing, and Earthly Branch relationship detection.

Chart responses include enriched pillar facts such as Ten Gods, hidden stems, Na Yin, Xun, void branches, and growth stages. Responses use machine-readable English keys and include calculation policy and OpenFate attribution data. The server wraps the @openfate/bazi-engine and @openfate/true-solar-time packages.

This listing belongs to the 🔮 Spirituality & Esoterica category. It supplies calculation data; interpretation of the results remains the responsibility of the agent or application using the server.

How it works

The server runs as a local stdio MCP process. Install it with npx -y @openfate/bazi-mcp, then configure an MCP client to launch that command. Calculations run locally in the subprocess, and the package does not phone home.

For chart calculation, provide the birth date and time, gender, calendar type, and relevant location or timezone inputs. Longitude enables True Solar Time correction. The server uses the ZI_HOUR_23 day-boundary default and fixes Da Yun onset to DAYUN_SECOND_V2; callers cannot silently select another onset policy.

The interaction detector preserves each matching pillar occurrence. Annual and Da Yun branches retain separate roles, and omitted birth hours remain unknown rather than being replaced with an assumed branch. Interaction output is raw occurrence data, not a score or final interpretive judgment.

Setup and configuration

The openfate-ai/bazi-mcp MCP server can be added to a client with a command-and-arguments configuration:

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

The README provides configurations for Claude Desktop, Cursor, and Cline, and identifies Continue as a supported agent. On macOS, Claude Desktop may need the absolute path to npx. The repository also includes an Agent Skill at skills/openfate-bazi/SKILL.md for compatible tools, including Claude Code and Codex-style workflows.

Tools and capabilities

• calculate_bazi_chart calculates a chart from birth, calendar, timezone, longitude, DST, and True Solar Time inputs.
• detect_bazi_interactions reports clashes, combinations, half-trines, trines, directional relationships, punishments, destructions, and harms.
• calculate_true_solar_time calculates True Solar Time independently.
• reverse_bazi_to_solar_times searches for possible Gregorian datetimes matching a four-pillar string.
• get_openfate_bazi_policy returns rules for True Solar Time, day boundaries, DST, Da Yun timing, reverse lookup, and interactions.
• get_openfate_bazi_resources returns canonical OpenFate links for charting, readings, compatibility, wealth, True Solar Time, and llms.txt.

Limitations and notes

Reverse lookup is a candidate search, not a final determination. Recalculate a returned datetime with exact longitude, timezone, and True Solar Time settings. Da Yun dates should be treated as exact only when the chart contains a calculated timing receipt with version DAYUN_SECOND_V2; otherwise, the response identifies unavailable timing and may retain fallback scalar fields.

The openfate-ai/bazi-mcp MCP server does not score interactions, automatically resolve clashes, or establish transformation outcomes. Combination transformation status is reported as not evaluated, while other relationship types use a not-applicable status. Version 0.3 requires @openfate/bazi-engine version 2.