list_realtime_publications

Instructions

Implementation Reference

• src/tools/list_realtime_publications.ts:42-78 (handler)

  The execute handler function that performs the tool logic: checks for direct PG connection, executes SQL query on pg_catalog.pg_publication, processes and validates the response using handleSqlResponse and Zod schema.

  execute: async (
      input: ListRealtimePublicationsInput,
      context: ToolContext
  ): Promise<ListRealtimePublicationsOutput> => {
      const client = context.selfhostedClient;
      console.error('Listing Realtime publications...');
  
      // Direct DB connection likely needed for pg_catalog access
      if (!client.isPgAvailable()) {
          context.log('Direct database connection (DATABASE_URL) is required to list publications.', 'error');
          throw new Error('Direct database connection (DATABASE_URL) is required to list publications.');
      }
  
      const sql = `
          SELECT
              oid,
              pubname,
              pubowner,
              puballtables,
              pubinsert,
              pubupdate,
              pubdelete,
              pubtruncate,
              pubviaroot
          FROM pg_catalog.pg_publication;
      `;
  
      console.error('Attempting to list publications using direct DB connection...');
      // Use executeSqlWithPg as it's a simple read query without parameters
      const result = await client.executeSqlWithPg(sql);
  
      const validatedPublications = handleSqlResponse(result, ListRealtimePublicationsOutputSchema);
  
      console.error(`Found ${validatedPublications.length} publications.`);
      context.log(`Found ${validatedPublications.length} publications.`);
      return validatedPublications;
  },

• src/tools/list_realtime_publications.ts:7-25 (schema)

  Zod schemas defining the input (empty object), output Publication model based on pg_publication columns, and output as array of Publications.

  // Input schema (no parameters needed)
  const ListRealtimePublicationsInputSchema = z.object({});
  type ListRealtimePublicationsInput = z.infer<typeof ListRealtimePublicationsInputSchema>;
  
  // Output schema based on pg_publication columns
  const PublicationSchema = z.object({
      oid: z.number().int(),
      pubname: z.string(),
      pubowner: z.number().int(), // Owner OID
      puballtables: z.boolean(),
      pubinsert: z.boolean(),
      pubupdate: z.boolean(),
      pubdelete: z.boolean(),
      pubtruncate: z.boolean(),
      pubviaroot: z.boolean(),
      // Potentially add pubownername if needed via join
  });
  const ListRealtimePublicationsOutputSchema = z.array(PublicationSchema);
  type ListRealtimePublicationsOutput = z.infer<typeof ListRealtimePublicationsOutputSchema>;

• src/tools/list_realtime_publications.ts:27-32 (schema)

  Static JSON schema for MCP tool input, as required by the protocol (empty object).

  // Static JSON schema for MCP (no parameters)
  export const mcpInputSchema = {
      type: 'object',
      properties: {},
      required: [],
  };

• src/index.ts:120-120 (registration)

  Registration of the list_realtime_publications tool in the availableTools object, which is used to populate the MCP server's tool capabilities.

  [listRealtimePublicationsTool.name]: listRealtimePublicationsTool as AppTool,

• src/index.ts:34-34 (registration)

  Import of the list_realtime_publications tool module.

  import listRealtimePublicationsTool from './tools/list_realtime_publications.js';