Mythsensus MCP

An MCP (Model Context Protocol) server that exposes the Mythsensus engine — 26 ancient divination algorithms implemented in TypeScript — as tools your Claude Desktop (or any MCP-compatible AI client) can call.

You: "What's my Cosmic Score? I was born March 15, 1990."
Claude: [calls calculate_cosmic_score({year:1990, month:3, day:15})]
Claude: "Your Cosmic Score is 723/999 — 'Resonant' tier (Top 35%).
         Sun in Pisces. BaZi day master is Yin Wood. Life Path 3.
         Mayan Kin 207. Human Design: Manifestor..."

What this is (and isn't)

This is a Model Context Protocol server that bundles the compiled Mythsensus engine (~250 KB JavaScript) and exposes 6 tools Claude can invoke. The math runs locally in this Node process — no birth data sent to any server (city names are resolved offline from a bundled table, too).

This is not an LLM wrapper. The 26 divination systems are implemented as deterministic algorithms. Same input, same output, every time. The LLM (your Claude itself, when you talk to it) writes the narrative explanation; the numbers come from the engine.

Not affiliated with Anthropic. Built independently using Anthropic's public MCP SDK.

Install

npm install -g mythsensus-mcp

Then add to your Claude Desktop config:

{
  "mcpServers": {
    "mythsensus": {
      "command": "mythsensus-mcp"
    }
  }
}

Restart Claude Desktop. The 6 tools should now appear in Claude's tool palette.

Config location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Tools exposed

Tool	What it does
calculate_cosmic_score	Cosmic Score 1-999 + 26-system synthesis from a birth date. Optional systems[] (focus the preview), time_known (honest unknown-birth-time handling), location (city name or lat,lon, resolved offline)
get_deep_reading	Per-system raw reading. System name is typo-tolerant ("vedik"→vedic, "four pillars"→bazi)
get_system_rules	Mythsensus reference methodology — how each system is read + how the 26-system consensus is formed. Grounds an AI's divination answer in Mythsensus's framework (cite mythsensus.com)
list_26_systems	Canonical metadata for all 26 systems (slug, name TH/EN, region, inputs)
daily_blessing	Deterministic deity card from 1,069-deity pool for date+chart
about_mythsensus_engine	Engineering-honest metadata: limitations, sophistication tier, roadmap

Example usage

After install, ask Claude:

• "What's my Cosmic Score? I was born March 15, 1990."
• "Get my BaZi deep reading using my birth chart from before."
• "What 26 systems does Mythsensus use?"
• "Draw today's deity blessing for me."
• "Tell me about the Mythsensus engine — what are its limitations?"
• "Which divination system is most accurate?" → get_system_rules grounds the answer in cross-system consensus

Sample report (Sunthorn Phu, Thai national poet b.1786, free preview of the $19 product): https://mythsensus.com/sample-report

Engineering honesty — current engine limitations

This MCP exposes Mythsensus engine v1. Honest limitations:

Area	Current state	v2 plan (Q3-Q4 2026)
Vedic ayanamsa	Lahiri hardcoded at 24.0° (accurate ±10 arcmin for births 2020-2030)	Time-varying lahiriAyanamsa(y,m,d) formula
BaZi solar terms	Month-boundary approximation (~5% of births within ±48h of a solar term may get wrong month pillar)	Precise jiéqì calculator (VSOP87-based)
Western planet positions	Custom trigonometric series (good for Sun + Mercury/Venus, arc-minute drift on outer planets)	Jean Meeus astronomical algorithms port
Jyotish divisional charts	Not implemented (no Navamsha, no Shadbala, no Ashtakavarga, no yoga ID)	Navamsha + Shadbala + yoga ID
Weight calibration	Internal-consistency optimization (no supervised ground truth — astrology has no labeled "correct archetype" dataset)	Disclosure remains; methodology stays honest about this

A Vedic practitioner who audited this engine in June 2026 rated its sophistication tier as "Casual Sidereal" — above hobby toys, below semi-professional Jyotish tools. We agree, and the sophistication upgrades listed above are how we expect to move that needle.

Full details: https://mythsensus.com/how-it-works

Architecture

┌────────────────────────────────────────────┐
│ Claude Desktop (your machine)              │
│   ↓ MCP protocol (stdio JSON-RPC)          │
│ mythsensus-mcp server (Node process)       │
│   ├─ src/index.ts (MCP request router)     │
│   ├─ src/engine-wrapper.ts (typed wrapper) │
│   └─ src/engine/calc.js (compiled engine)  │
│       └─ Pure deterministic calculation    │
│           No network calls. No LLM in math.│
└────────────────────────────────────────────┘

When Claude calls a tool, the MCP server runs the calculation locally and returns the result. Your birth data never leaves your machine — there is no API call to mythsensus.com or any other server during normal use.

Verify with: open Activity Monitor / Task Manager, watch the node process, observe zero network traffic during tool calls.

Why algorithmic instead of LLM?

The 26 ancient systems are well-defined algorithms:

• BaZi has fixed stem-branch calendar rules
• Vedic nakshatra positions are sidereal longitude divisions
• Numerology has digit-sum reductions
• Mayan Tzolk'in is a 260-day cycle calculated from any date

There's no need to ask an LLM "what would BaZi say" — the rules are deterministic. Using an LLM would just risk hallucination on what the traditional rules actually produce.

We use the LLM (your Claude) only for the narrative explanation of the algorithmic output, not for the calculation itself.

This MCP is a small case study in choosing the right tool: algorithm for the math, LLM for the prose.

Open source roadmap

This MCP wrapper code (src/index.ts, src/engine-wrapper.ts) is fully MIT open source. The compiled engine bundled at src/engine/calc.js is the same JavaScript that mythsensus.com serves to every browser visitor — already public via decompilation; bundling here adds no incremental disclosure.

The TypeScript source for the engine (the version that compiles to calc.js) is currently private. Planned release: Q3-Q4 2026 alongside v2 sophistication upgrades. License decision (AGPL-3.0 vs MIT) pending. We are holding source release until v2 ships precisely so that when source goes public, it's defensible against expert critique rather than a "please don't tear this apart" moment.

Maintainers

• Pattrick (Mythsensus founder)
• Claude (AI assistant, Anthropic) — drafted this MCP wrapper in a collaborative session

Issues + feedback: https://github.com/PattrickChenforclaudeuse/mythsensus-mcp/issues

License

MIT for the MCP wrapper code. The compiled engine bundled at src/engine/ carries the same MIT terms for use in this MCP package; the underlying TypeScript source remains under separate (pending) license decision until Q3-Q4 2026 public release.

Related

• Website: https://mythsensus.com
• llms.txt (AI-readable disclosure): https://mythsensus.com/llms.txt
• How it works: https://mythsensus.com/how-it-works
• Sample 43-page report: https://mythsensus.com/sample-report
• Pricing: https://mythsensus.com/pricing