notion_retrieve_block_children
Retrieve child blocks from a Notion page or block to access nested content and structure within your workspace.
Instructions
Retrieve the children of a block
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| block_id | Yes | The ID of the block.It should be a 32-character string (excluding hyphens) formatted as 8-4-4-4-12 with hyphens (-). | |
| format | No | Specify the response format. 'json' returns the original data structure, 'markdown' returns a more readable format. Use 'markdown' when the user only needs to read the page and isn't planning to write or modify it. Use 'json' when the user needs to read the page with the intention of writing to or modifying it. | markdown |
| page_size | No | Number of results per page (max 100) | |
| start_cursor | No | Pagination cursor for next page of results |
Implementation Reference
- src/client/index.ts:60-78 (handler)Core implementation of retrieveBlockChildren in NotionClientWrapper: constructs API URL with optional pagination params and fetches from Notion API /blocks/{block_id}/children endpoint.async retrieveBlockChildren( block_id: string, start_cursor?: string, page_size?: number ): Promise<ListResponse> { const params = new URLSearchParams(); if (start_cursor) params.append("start_cursor", start_cursor); if (page_size) params.append("page_size", page_size.toString()); const response = await fetch( `${this.baseUrl}/blocks/${block_id}/children?${params}`, { method: "GET", headers: this.headers, } ); return response.json(); }
- src/server/index.ts:76-87 (registration)MCP tool handler registration: switch case that validates args and delegates to notionClient.retrieveBlockChildrencase "notion_retrieve_block_children": { const args = request.params .arguments as unknown as args.RetrieveBlockChildrenArgs; if (!args.block_id) { throw new Error("Missing required argument: block_id"); } response = await notionClient.retrieveBlockChildren( args.block_id, args.start_cursor, args.page_size ); break;
- src/types/schemas.ts:59-81 (schema)Tool schema definition: specifies name, description, input schema with properties for block_id (required), optional pagination, and format.export const retrieveBlockChildrenTool: Tool = { name: "notion_retrieve_block_children", description: "Retrieve the children of a block", inputSchema: { type: "object", properties: { block_id: { type: "string", description: "The ID of the block." + commonIdDescription, }, start_cursor: { type: "string", description: "Pagination cursor for next page of results", }, page_size: { type: "number", description: "Number of results per page (max 100)", }, format: formatParameter, }, required: ["block_id"], }, };
- src/types/args.ts:20-25 (schema)TypeScript interface defining the arguments for the retrieveBlockChildren tool, used for type safety in the handler.export interface RetrieveBlockChildrenArgs { block_id: string; start_cursor?: string; page_size?: number; format?: "json" | "markdown"; }
- src/server/index.ts:306-307 (registration)Tool inclusion in the allTools array for ListTools MCP request, enabling discovery of the tool.schemas.retrieveBlockChildrenTool, schemas.deleteBlockTool,