notion_retrieve_block_children
Retrieve and manage child blocks of a Notion block in JSON or Markdown format, enabling content access, pagination, and structured data handling for integrations.
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/server/index.ts:76-87 (handler)MCP tool handler switch case that validates input arguments and delegates to the NotionClientWrapper.retrieveBlockChildren method.case "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/client/index.ts:60-78 (helper)Core helper function in NotionClientWrapper that performs the Notion API GET request to retrieve the children of a block, handling pagination parameters.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/types/schemas.ts:59-81 (schema)JSON schema definition for the notion_retrieve_block_children tool, including input parameters and descriptions.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/server/index.ts:303-325 (registration)Tool registration by including retrieveBlockChildrenTool in the allTools array returned in ListToolsRequest handler.const allTools = [ schemas.appendBlockChildrenTool, schemas.retrieveBlockTool, schemas.retrieveBlockChildrenTool, schemas.deleteBlockTool, schemas.updateBlockTool, schemas.retrievePageTool, schemas.updatePagePropertiesTool, schemas.listAllUsersTool, schemas.retrieveUserTool, schemas.retrieveBotUserTool, schemas.createDatabaseTool, schemas.queryDatabaseTool, schemas.retrieveDatabaseTool, schemas.updateDatabaseTool, schemas.createDatabaseItemTool, schemas.createCommentTool, schemas.retrieveCommentsTool, schemas.searchTool, ]; return { tools: filterTools(allTools, enabledToolsSet), };
- src/types/args.ts:20-25 (schema)TypeScript type definition for the tool arguments used in the handler.export interface RetrieveBlockChildrenArgs { block_id: string; start_cursor?: string; page_size?: number; format?: "json" | "markdown"; }