API-patch-block-children
Append child content to a Notion block or page using the Notion MCP Server. Specify block ID and array of child blocks to add content after an existing block, enhancing workspace organization.
Instructions
Notion | Append block children
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| after | No | The ID of the existing block that the new block should be appended after. | |
| block_id | Yes | Identifier for a [block](ref:block). Also accepts a [page](ref:page) ID. | |
| children | Yes | Child content to append to a container block as an array of [block objects](ref:block) |
Implementation Reference
- Generic MCP tool execution handler for all tools derived from OpenAPI spec, including "API-patch-block-children". It resolves the tool name to the corresponding OpenAPI operation (PATCH /v1/blocks/{block_id}/children), executes the HTTP request via HttpClient, and formats the response as MCP content.this.server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: params } = request.params // Find the operation in OpenAPI spec const operation = this.findOperation(name) if (!operation) { throw new Error(`Method ${name} not found`) } try { // Execute the operation const response = await this.httpClient.executeOperation(operation, params) // Convert response to MCP format return { content: [ { type: 'text', // currently this is the only type that seems to be used by mcp server text: JSON.stringify(response.data), // TODO: pass through the http status code text? }, ], } } catch (error) { console.error('Error in tool call', error) if (error instanceof HttpClientError) { console.error('HttpClientError encountered, returning structured error', error) const data = error.data?.response?.data ?? error.data ?? {} return { content: [ { type: 'text', text: JSON.stringify({ status: 'error', // TODO: get this from http status code? ...(typeof data === 'object' ? data : { data: data }), }), }, ], } } throw error } })
- src/openapi-mcp-server/mcp/proxy.ts:58-75 (registration)MCP tool listing handler that registers all OpenAPI-derived tools, constructing names like "API-patch-block-children" from 'API' + operationId 'patch-block-children', including description and inputSchema.this.server.setRequestHandler(ListToolsRequestSchema, async () => { const tools: Tool[] = [] // Add methods as separate tools to match the MCP format Object.entries(this.tools).forEach(([toolName, def]) => { def.methods.forEach(method => { const toolNameWithMethod = `${toolName}-${method.name}`; const truncatedToolName = this.truncateToolName(toolNameWithMethod); tools.push({ name: truncatedToolName, description: method.description, inputSchema: method.inputSchema as Tool['inputSchema'], }) }) }) return { tools } })
- Generates MCP tool definitions (name, description, inputSchema) from OpenAPI operations, creating the "API-patch-block-children" tool from Notion's patchBlockChildren operation including schema for path param block_id and body.convertToMCPTools(): { tools: Record<string, { methods: NewToolMethod[] }> openApiLookup: Record<string, OpenAPIV3.OperationObject & { method: string; path: string }> zip: Record<string, { openApi: OpenAPIV3.OperationObject & { method: string; path: string }; mcp: NewToolMethod }> } { const apiName = 'API' const openApiLookup: Record<string, OpenAPIV3.OperationObject & { method: string; path: string }> = {} const tools: Record<string, { methods: NewToolMethod[] }> = { [apiName]: { methods: [] }, } const zip: Record<string, { openApi: OpenAPIV3.OperationObject & { method: string; path: string }; mcp: NewToolMethod }> = {} for (const [path, pathItem] of Object.entries(this.openApiSpec.paths || {})) { if (!pathItem) continue for (const [method, operation] of Object.entries(pathItem)) { if (!this.isOperation(method, operation)) continue const mcpMethod = this.convertOperationToMCPMethod(operation, method, path) if (mcpMethod) { const uniqueName = this.ensureUniqueName(mcpMethod.name) mcpMethod.name = uniqueName mcpMethod.description = this.getDescription(operation.summary || operation.description || '') tools[apiName]!.methods.push(mcpMethod) openApiLookup[apiName + '-' + uniqueName] = { ...operation, method, path } zip[apiName + '-' + uniqueName] = { openApi: { ...operation, method, path }, mcp: mcpMethod } } } } return { tools, openApiLookup, zip } }
- src/openapi-mcp-server/mcp/proxy.ts:48-54 (registration)Initializes the MCPProxy by converting Notion OpenAPI spec to internal tools map and openApiLookup (used for dispatching), including the entry for "API-patch-block-children".const converter = new OpenAPIToMCPConverter(openApiSpec) const { tools, openApiLookup } = converter.convertToMCPTools() this.tools = tools this.openApiLookup = openApiLookup this.setupHandlers() }
- Dispatches to HttpClient.executeOperation which performs the actual HTTP PATCH request for the tool.const response = await this.httpClient.executeOperation(operation, params)