DynamoDB MCP Server

Instructions

Implementation Reference

• src/index.ts:439-462 (handler)

  The main handler function for the 'update_capacity' tool. It uses UpdateTableCommand to update the provisioned throughput (read/write capacity) of a DynamoDB table.

  async function updateCapacity(params: any) {
    try {
      const command = new UpdateTableCommand({
        TableName: params.tableName,
        ProvisionedThroughput: {
          ReadCapacityUnits: params.readCapacity,
          WriteCapacityUnits: params.writeCapacity,
        },
      });
      
      const response = await dynamoClient.send(command);
      return {
        success: true,
        message: `Capacity updated successfully for table ${params.tableName}`,
        details: response.TableDescription,
      };
    } catch (error) {
      console.error("Error updating capacity:", error);
      return {
        success: false,
        message: `Failed to update capacity: ${error}`,
      };
    }
  }

• src/index.ts:148-160 (schema)

  The Tool object definition for 'update_capacity', including name, description, and inputSchema for validation.

  const UPDATE_CAPACITY_TOOL: Tool = {
    name: "update_capacity",
    description: "Updates the provisioned capacity of a table",
    inputSchema: {
      type: "object",
      properties: {
        tableName: { type: "string", description: "Name of the table" },
        readCapacity: { type: "number", description: "New read capacity units" },
        writeCapacity: { type: "number", description: "New write capacity units" },
      },
      required: ["tableName", "readCapacity", "writeCapacity"],
    },
  };

• src/index.ts:598-600 (registration)

  Registers the UPDATE_CAPACITY_TOOL in the list returned by ListToolsRequestHandler.

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools: [CREATE_TABLE_TOOL, UPDATE_CAPACITY_TOOL, PUT_ITEM_TOOL, GET_ITEM_TOOL, QUERY_TABLE_TOOL, SCAN_TABLE_TOOL, DESCRIBE_TABLE_TOOL, LIST_TABLES_TOOL, CREATE_GSI_TOOL, UPDATE_GSI_TOOL, CREATE_LSI_TOOL, UPDATE_ITEM_TOOL],
  }));

• src/index.ts:626-628 (registration)

  Dispatches tool calls to the updateCapacity handler in the CallToolRequestHandler switch statement.

  case "update_capacity":
    result = await updateCapacity(args);
    break;