Notion MCP Server

Implementation Reference

• src/index.ts:325-417 (registration)

  Registration of the 'query-database' tool using server.tool(), including inline schema and handler function.

  server.tool(
    "query-database",
    { 
      databaseId: z.string(),
      filter: z.any().optional(),
      sort: z.any().optional()
    },
    async ({ databaseId, filter, sort }) => {
      try {
        // Prepare query parameters
        const queryParams: any = {
          database_id: databaseId
        };
        
        // Add filter if provided
        if (filter) {
          queryParams.filter = filter;
        }
        
        // Add sort if provided
        if (sort) {
          queryParams.sorts = sort;
        }
        
        // Query the database
        const response = await notion.databases.query(queryParams);
        
        // Format the results
        const formattedResults = response.results.map((page: any) => {
          // Extract properties in a more readable format
          const formattedProperties: any = {};
          
          Object.entries(page.properties).forEach(([key, value]: [string, any]) => {
            // Handle different property types
            switch (value.type) {
              case 'title':
                formattedProperties[key] = value.title.map((t: any) => t.plain_text).join('');
                break;
              case 'rich_text':
                formattedProperties[key] = value.rich_text.map((t: any) => t.plain_text).join('');
                break;
              case 'number':
                formattedProperties[key] = value.number;
                break;
              case 'select':
                formattedProperties[key] = value.select?.name || null;
                break;
              case 'multi_select':
                formattedProperties[key] = value.multi_select.map((s: any) => s.name);
                break;
              case 'date':
                formattedProperties[key] = value.date?.start || null;
                break;
              case 'checkbox':
                formattedProperties[key] = value.checkbox;
                break;
              case 'url':
                formattedProperties[key] = value.url;
                break;
              case 'email':
                formattedProperties[key] = value.email;
                break;
              case 'phone_number':
                formattedProperties[key] = value.phone_number;
                break;
              default:
                formattedProperties[key] = 'Unsupported property type: ' + value.type;
            }
          });
          
          return {
            id: page.id,
            properties: formattedProperties
          };
        });
        
        return {
          content: [{
            type: "text",
            text: JSON.stringify(formattedResults, null, 2)
          }]
        };
      } catch (error: any) {
        return {
          content: [{
            type: "text",
            text: `Error querying database: ${error.message}`
          }],
          isError: true
        };
      }
    }
  );

• src/index.ts:327-331 (schema)

  Input schema using Zod: databaseId (string, required), filter (any, optional), sort (any, optional).

  { 
    databaseId: z.string(),
    filter: z.any().optional(),
    sort: z.any().optional()
  },

• src/index.ts:332-416 (handler)

  Handler function that queries the Notion database with the given databaseId, applies optional filter and sort parameters, processes and formats the results by converting various Notion property types to simple JSON values, and returns the formatted results as a text content block or an error message.

  async ({ databaseId, filter, sort }) => {
    try {
      // Prepare query parameters
      const queryParams: any = {
        database_id: databaseId
      };
      
      // Add filter if provided
      if (filter) {
        queryParams.filter = filter;
      }
      
      // Add sort if provided
      if (sort) {
        queryParams.sorts = sort;
      }
      
      // Query the database
      const response = await notion.databases.query(queryParams);
      
      // Format the results
      const formattedResults = response.results.map((page: any) => {
        // Extract properties in a more readable format
        const formattedProperties: any = {};
        
        Object.entries(page.properties).forEach(([key, value]: [string, any]) => {
          // Handle different property types
          switch (value.type) {
            case 'title':
              formattedProperties[key] = value.title.map((t: any) => t.plain_text).join('');
              break;
            case 'rich_text':
              formattedProperties[key] = value.rich_text.map((t: any) => t.plain_text).join('');
              break;
            case 'number':
              formattedProperties[key] = value.number;
              break;
            case 'select':
              formattedProperties[key] = value.select?.name || null;
              break;
            case 'multi_select':
              formattedProperties[key] = value.multi_select.map((s: any) => s.name);
              break;
            case 'date':
              formattedProperties[key] = value.date?.start || null;
              break;
            case 'checkbox':
              formattedProperties[key] = value.checkbox;
              break;
            case 'url':
              formattedProperties[key] = value.url;
              break;
            case 'email':
              formattedProperties[key] = value.email;
              break;
            case 'phone_number':
              formattedProperties[key] = value.phone_number;
              break;
            default:
              formattedProperties[key] = 'Unsupported property type: ' + value.type;
          }
        });
        
        return {
          id: page.id,
          properties: formattedProperties
        };
      });
      
      return {
        content: [{
          type: "text",
          text: JSON.stringify(formattedResults, null, 2)
        }]
      };
    } catch (error: any) {
      return {
        content: [{
          type: "text",
          text: `Error querying database: ${error.message}`
        }],
        isError: true
      };
    }
  }