
yarrow
I-Ching (周易) oracle: cast a hexagram, read classical commentary, get a reflection.
What it can do
What data it sees
Do you need an account
No: the server works without sign-in
I-Ching (周易) oracle: cast a hexagram, read classical commentary, get a reflection. Bilingual.
How to connect
How to connect yarrow to Claude
The server address to paste into Claude settings:
https://yarrow-oracle.shaozhengkun.workers.dev/mcp
- Open Claude (claude.ai or the desktop app).
- Go to Settings → Connectors.
- Click Add custom connector.
- Paste the server address copied below into Remote MCP server URL and click Add.
- In a chat, click + → Connectors and switch the new connector on.
Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.
Authorization
After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.
How to connect yarrow to ChatGPT
The server address to paste into ChatGPT settings:
https://yarrow-oracle.shaozhengkun.workers.dev/mcp
- Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
- Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
- Open Settings → Connectors and click Create.
- Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
- Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
- In a new chat open + → Apps/Connectors and enable the connector.
OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.
Authorization
On first use ChatGPT opens the service's sign-in window. Sign in and approve access.
How to connect yarrow to Cursor
The server address to paste into Cursor settings:
https://yarrow-oracle.shaozhengkun.workers.dev/mcp
Fastest: click Open in Cursor below and confirm the prompt.
Manually:
- In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
- Paste the JSON copied below into
~/.cursor/mcp.json(per project:.cursor/mcp.jsonin the repo root). - Save the file. The server appears in the MCP list; authorize it there if asked.
Authorization
If the service needs sign-in, an authorize button appears next to the server in the MCP list.
Server tool list (7)
Raw names from tools/list. Only developers need these.
| cast_hexagram | 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). |
| lookup_hexagram | 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_yilin | 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. |
| cast_tarot | 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. |
| divine | 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. |
| tarot_reading | 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. |
| two_lenses | 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. |