siyuan – Coding skill for AI agents

SiYuan Note API

Use the [SiYuan](https://github.com/siyuan-note/siyuan) kernel API via curl to search, read, create, update, and delete blocks and documents in a self-hosted knowledge base. No extra tools needed -- just curl and an API token.

Prerequisites

1. Install and run SiYuan (desktop or Docker)

2. Get your API token: Settings > About > API token

3. Store it in ${HERMES_HOME:-~/.hermes}/.env:

   SIYUAN_TOKEN=your_token_here
   SIYUAN_URL=http://127.0.0.1:6806
   

SIYUAN_URL defaults to http://127.0.0.1:6806 if not set.

API Basics

All SiYuan API calls are POST with JSON body. Every request follows this pattern:

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/..." \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"param": "value"}'

Responses are JSON with this structure:

{"code": 0, "msg": "", "data": { ... }}

code: 0 means success. Any other value is an error -- check msg for details.

ID format: SiYuan IDs look like 20210808180117-6v0mkxr (14-digit timestamp + 7 alphanumeric chars).

Quick Reference

| Operation | Endpoint |

|-----------|----------|

| Full-text search | /api/search/fullTextSearchBlock |

| SQL query | /api/query/sql |

| Read block | /api/block/getBlockKramdown |

| Read children | /api/block/getChildBlocks |

| Get path | /api/filetree/getHPathByID |

| Get attributes | /api/attr/getBlockAttrs |

| List notebooks | /api/notebook/lsNotebooks |

| List documents | /api/filetree/listDocsByPath |

| Create notebook | /api/notebook/createNotebook |

| Create document | /api/filetree/createDocWithMd |

| Append block | /api/block/appendBlock |

| Update block | /api/block/updateBlock |

| Rename document | /api/filetree/renameDocByID |

| Set attributes | /api/attr/setBlockAttrs |

| Delete block | /api/block/deleteBlock |

| Delete document | /api/filetree/removeDocByID |

| Export as Markdown | /api/export/exportMdContent |

Common Operations

Search (Full-Text)

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/search/fullTextSearchBlock" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"query": "meeting notes", "page": 0}' | jq '.data.blocks[:5]'

Search (SQL)

Query the blocks database directly. Only SELECT statements are safe.

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/query/sql" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"stmt": "SELECT id, content, type, box FROM blocks WHERE content LIKE '\''%keyword%'\'' AND type='\''p'\'' LIMIT 20"}' | jq '.data'

Useful columns: id, parent_id, root_id, box (notebook ID), path, content, type, subtype, created, updated.

Read Block Content

Returns block content in Kramdown (Markdown-like) format.

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/block/getBlockKramdown" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "20210808180117-6v0mkxr"}' | jq '.data.kramdown'

Read Child Blocks

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/block/getChildBlocks" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "20210808180117-6v0mkxr"}' | jq '.data'

Get Human-Readable Path

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/filetree/getHPathByID" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "20210808180117-6v0mkxr"}' | jq '.data'

Get Block Attributes

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/attr/getBlockAttrs" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "20210808180117-6v0mkxr"}' | jq '.data'

List Notebooks

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/notebook/lsNotebooks" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{}' | jq '.data.notebooks[] | {id, name, closed}'

List Documents in a Notebook

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/filetree/listDocsByPath" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"notebook": "NOTEBOOK_ID", "path": "/"}' | jq '.data.files[] | {id, name}'

Create a Document

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/filetree/createDocWithMd" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "notebook": "NOTEBOOK_ID",
    "path": "/Meeting Notes/2026-03-22",
    "markdown": "# Meeting Notes\n\n- Discussed project timeline\n- Assigned tasks"
  }' | jq '.data'

Create a Notebook

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/notebook/createNotebook" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "My New Notebook"}' | jq '.data.notebook.id'

Append Block to Document

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/block/appendBlock" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "parentID": "DOCUMENT_OR_BLOCK_ID",
    "data": "New paragraph added at the end.",
    "dataType": "markdown"
  }' | jq '.data'

Also available: /api/block/prependBlock (same params, inserts at the beginning) and /api/block/insertBlock (uses previousID instead of parentID to insert after a specific block).

Update Block Content

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/block/updateBlock" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "id": "BLOCK_ID",
    "data": "Updated content here.",
    "dataType": "markdown"
  }' | jq '.data'

Rename a Document

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/filetree/renameDocByID" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "DOCUMENT_ID", "title": "New Title"}'

Set Block Attributes

Custom attributes must be prefixed with custom-:

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/attr/setBlockAttrs" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "id": "BLOCK_ID",
    "attrs": {
      "custom-status": "reviewed",
      "custom-priority": "high"
    }
  }'

Delete a Block

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/block/deleteBlock" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "BLOCK_ID"}'

To delete a whole document: use /api/filetree/removeDocByID with {"id": "DOC_ID"}.

To delete a notebook: use /api/notebook/removeNotebook with {"notebook": "NOTEBOOK_ID"}.

Export Document as Markdown

curl -s -X POST "${SIYUAN_URL:-http://127.0.0.1:6806}/api/export/exportMdContent" \
  -H "Authorization: Token $SIYUAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"id": "DOCUMENT_ID"}' | jq -r '.data.content'

Block Types

Common type values in SQL queries:

| Type | Description |

|------|-------------|

| d | Document (root block) |

| p | Paragraph |

| h | Heading |

| l | List |

| i | List item |

| c | Code block |

| m | Math block |

| t | Table |

| b | Blockquote |

| s | Super block |

| html | HTML block |

Pitfalls

• All endpoints are POST -- even read-only operations. Do not use GET.
• SQL safety: only use SELECT queries. INSERT/UPDATE/DELETE/DROP are dangerous and should never be sent.
• ID validation: IDs match the pattern YYYYMMDDHHmmss-xxxxxxx. Reject anything else.
• Error responses: always check code != 0 in responses before processing data.
• Large documents: block content and export results can be very large. Use LIMIT in SQL and pipe through jq to extract only what you need.
• Notebook IDs: when working with a specific notebook, get its ID first via lsNotebooks.

Alternative: MCP Server

If you prefer a native integration instead of curl, install the SiYuan MCP server:

# In ~/.hermes/config.yaml under mcp_servers:
mcp_servers:
  siyuan:
    command: npx
    args: ["-y", "@porkll/siyuan-mcp"]
    env:
      SIYUAN_TOKEN: "your_token"
      SIYUAN_URL: "http://127.0.0.1:6806"