Koskamo

Yarrow MCP

A public MCP server for the I-Ching oracle that allows LLM agents to cast hexagrams, look up classical bilingual commentaries, and receive reflections grounded in traditional sources. It supports deterministic casting and provides three tools for divination and interpretation.

Endpoint and access

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Yarrow MCP logo, by shaozhengkun123Community listingStreamable HTTPNo sign-inEndpoint checked 2026-11-06Published by shaozhengkun123
MCP endpoint (Streamable HTTP)
https://yarrow-oracle.shaozhengkun.workers.dev/mcp
Vendor documentation

What its tools do

7 tools, grouped by the hints the server advertises. Hints are self-declared, not verified behavior.

Not annotated (7)

7 of 7 have a description · 0 of 7 declare behavior hints · 3 of 7 with parameters document them all

Checks and signals

Each line is separate evidence, not a trust score.

  • Passed Endpoint answered the live check ·
  • Availability 1 of 1 checks passed in 30 days

What you can do with it

  • Casting a hexagram using coins or yarrow stalks
  • Looking up classical text and commentaries for a hexagram
  • Generating a one-shot reflection based on a user's question

Source and maintenance

Community listingRegistry 0.1.0
mcp-registry: io.github.shaozhengkun123/yarrow@0.1.0Source repository
Maintenance checked

Protocol and capabilities

Server
yarrow 0.1.0
MCP protocol negotiated in check
2025-03-26
Tools
7 advertised
Resources
Not advertised
Resource templates
Not advertised
Prompts
Not advertised
Server-advertised capabilities
{
  "tools": {}
}

Tools

7 advertised

cast_hexagram
Advertised by the server during the last successful anonymous check.

Cast a hexagram for an I-Ching consultation. Returns the primary hexagram, the six lines (6=old yin, 7=young yang, 8=young yin, 9=old yang from bottom to top), any moving lines, and the changing hexagram if there are moving lines. Pass `seed` to make the cast deterministic (useful for testing or for reproducing a reading).

cast_hexagram input schema
{
  "type": "object",
  "required": [],
  "properties": {
    "seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Optional seed for deterministic casting."
    },
    "method": {
      "enum": [
        "coins",
        "yarrow",
        "random"
      ],
      "type": "string",
      "default": "coins",
      "description": "coins = three-coin toss (most common); yarrow = traditional 50-stalk probabilities; random = uniformly pick one of the 64 hexagrams with no moving lines."
    },
    "question": {
      "type": "string",
      "description": "The question being asked (not used for casting, returned in result for context)."
    }
  }
}
lookup_hexagram
Advertised by the server during the last successful anonymous check.

Return the full classical sources for a hexagram by its number (1–64): judgment (卦辞), image (大象), Tuan commentary, Zhu Xi 周易本义, Yang Tian Cai modern explanation, Yarrow's separately labelled Chinese reading aid, and historical anecdote — with available Chinese and English source material.

lookup_hexagram input schema
{
  "type": "object",
  "required": [
    "number"
  ],
  "properties": {
    "locale": {
      "enum": [
        "en",
        "zh",
        "both"
      ],
      "type": "string",
      "default": "both"
    },
    "number": {
      "type": "integer",
      "maximum": 64,
      "minimum": 1,
      "description": "Hexagram number 1-64 in King Wen sequence."
    },
    "compact": {
      "type": "boolean",
      "default": false,
      "description": "If true, omit authorities (long classical commentary). Returns only structural fields."
    }
  }
}
lookup_yilin
Advertised by the server during the last successful anonymous check.

Look up the 焦氏易林 verse for a primary hexagram changing into another hexagram. This is a local classical-source lookup, not an AI reading.

lookup_yilin input schema
{
  "type": "object",
  "required": [
    "primary_number",
    "changing_number"
  ],
  "properties": {
    "primary_number": {
      "type": "integer",
      "maximum": 64,
      "minimum": 1,
      "description": "Primary hexagram number 1-64."
    },
    "changing_number": {
      "type": "integer",
      "maximum": 64,
      "minimum": 1,
      "description": "Changing hexagram number 1-64."
    }
  }
}
cast_tarot
Advertised by the server during the last successful anonymous check.

Draw one upright Major Arcana card for reflection. Uses a deterministic one-card Waite-Smith Major Arcana method and returns a selected source excerpt from Arthur Edward Waite's public-domain 1910/1922 text. Pass `seed` to reproduce the same draw.

cast_tarot input schema
{
  "type": "object",
  "required": [],
  "properties": {
    "seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Optional deterministic draw seed."
    },
    "question": {
      "type": "string",
      "description": "The question being reflected on (not used to influence the draw)."
    }
  }
}
divine
Advertised by the server during the last successful anonymous check.

Ask the I Ching. See your next step. Cast a hexagram, show the classical sources first, then offer a thoughtful reflection grounded in those sources. Sources first. Reflection, not prediction. The divine name remains stable for oracle/divination client compatibility. Supports English, Chinese, Japanese, Korean, Spanish, French, German, Portuguese, Italian, Russian, Arabic, Hindi, Indonesian, and English+Chinese bilingual output. Daily quota: 30 completed readings per device_id (or per anonymous IP if no device_id is supplied); timeout, provider failure, incomplete response, and cancellation do not consume it.

divine input schema
{
  "type": "object",
  "required": [
    "question"
  ],
  "properties": {
    "seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Deterministic cast seed."
    },
    "locale": {
      "enum": [
        "en",
        "zh",
        "zh-Hant",
        "ja",
        "ko",
        "es",
        "fr",
        "de",
        "pt",
        "it",
        "ru",
        "ar",
        "hi",
        "id",
        "bilingual"
      ],
      "type": "string",
      "default": "en"
    },
    "method": {
      "enum": [
        "coins",
        "yarrow",
        "random"
      ],
      "type": "string",
      "default": "coins"
    },
    "question": {
      "type": "string",
      "description": "The question to consult on."
    },
    "device_id": {
      "type": "string",
      "description": "Optional opaque identifier for quota tracking. If omitted, IP-derived."
    }
  }
}
tarot_reading
Advertised by the server during the last successful anonymous check.

Ask one real question through a single upright Waite-Smith Major Arcana card. Returns a direct calibrated answer first, the named card and bound Arthur Edward Waite 1910 source excerpt, a practical reality check, and one observable next step. No reversals, astrology, redraw loop, or guaranteed prediction. Daily quota is shared with completed divine and Two Lenses readings.

tarot_reading input schema
{
  "type": "object",
  "required": [
    "question"
  ],
  "properties": {
    "seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Deterministic Tarot draw seed."
    },
    "locale": {
      "enum": [
        "en",
        "zh",
        "zh-Hant",
        "ja",
        "ko",
        "es",
        "fr",
        "de",
        "pt",
        "it",
        "ru",
        "ar",
        "hi",
        "id",
        "bilingual"
      ],
      "type": "string",
      "default": "en"
    },
    "question": {
      "type": "string",
      "description": "The real question to reflect on."
    },
    "device_id": {
      "type": "string",
      "description": "Optional opaque identifier for quota tracking. If omitted, IP-derived."
    }
  }
}
two_lenses
Advertised by the server during the last successful anonymous check.

Bring one real question to two independent symbolic traditions: a source-first I-Ching cast and one upright Waite-Smith Major Arcana card. Returns a clear calibrated answer first, then five grounded sections covering the I Ching lens, Tarot lens, shared themes, different emphasis, and next step. Direction without guaranteed prediction or mutual-confirmation claims. Daily quota is shared with completed divine readings.

two_lenses input schema
{
  "type": "object",
  "required": [
    "question"
  ],
  "properties": {
    "locale": {
      "enum": [
        "en",
        "zh",
        "zh-Hant",
        "ja",
        "ko",
        "es",
        "fr",
        "de",
        "pt",
        "it",
        "ru",
        "ar",
        "hi",
        "id",
        "bilingual"
      ],
      "type": "string",
      "default": "en"
    },
    "method": {
      "enum": [
        "coins",
        "yarrow",
        "random"
      ],
      "type": "string",
      "default": "coins"
    },
    "question": {
      "type": "string",
      "description": "The same real question for both lenses."
    },
    "device_id": {
      "type": "string",
      "description": "Optional opaque identifier for quota tracking. If omitted, IP-derived."
    },
    "tarot_seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Deterministic Tarot draw seed."
    },
    "iching_seed": {
      "type": [
        "string",
        "number"
      ],
      "description": "Deterministic I-Ching cast seed."
    }
  }
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks
1 of 1 (100%)
Average latency
257 ms
95th percentile latency
257 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

  • · probe · passed · 257 ms · metadata changed · 7 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.
Claude Code configuration
claude mcp add --transport http yarrow-mcp-workers https://yarrow-oracle.shaozhengkun.workers.dev/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).
Codex configuration
codex mcp add yarrow-mcp-workers --url https://yarrow-oracle.shaozhengkun.workers.dev/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable yarrow-mcp-workers in your MCP settings.
Cursor configuration
{
  "mcpServers": {
    "yarrow-mcp-workers": {
      "url": "https://yarrow-oracle.shaozhengkun.workers.dev/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).
Cline configuration
{
  "mcpServers": {
    "yarrow-mcp-workers": {
      "type": "streamableHttp",
      "url": "https://yarrow-oracle.shaozhengkun.workers.dev/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start yarrow-mcp-workers and inspect its tools.
VS Code configuration
{
  "servers": {
    "yarrow-mcp-workers": {
      "type": "http",
      "url": "https://yarrow-oracle.shaozhengkun.workers.dev/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.
Gemini CLI configuration
gemini mcp add --transport http yarrow-mcp-workers https://yarrow-oracle.shaozhengkun.workers.dev/mcp

Claude Desktop

Open Claude Settings > Connectors > Add custom connector, enter this server URL and enable it for the conversation. This is a manual remote-connector handoff, not a desktop JSON configuration.
Claude Desktop configuration
https://yarrow-oracle.shaozhengkun.workers.dev/mcp

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.
Windsurf configuration
{
  "mcpServers": {
    "yarrow-mcp-workers": {
      "serverUrl": "https://yarrow-oracle.shaozhengkun.workers.dev/mcp"
    }
  }
}

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