Perplexity MCP Server

Instructions

Implementation Reference

• src/handlers/RecencyFilterHandler.ts:11-33 (handler)

  RecencyFilterHandler class that implements the core logic for the recency_filter tool: validates input arguments and delegates to FilterState to set the filter.

  export class RecencyFilterHandler {
  	constructor(private filterState: FilterState) {}
  
  	async handle(request: McpRequest) {
  		if (!isValidRecencyArgs(request.params.arguments)) {
  			throw ErrorHandler.createMcpError(
  				ErrorCode.InvalidParams,
  				"Invalid recency filter argument. Filter must be one of: hour, day, week, month, none."
  			);
  		}
  
  		const { filter } = request.params.arguments as RecencyArgs;
  		const resultMessage = this.filterState.setRecencyFilter(filter);
  
  		return {
  			content: [
  				{
  					type: "text",
  					text: resultMessage,
  				},
  			],
  		};
  	}

• src/schemas/toolSchemas.ts:46-58 (schema)

  JSON schema definition for the recency_filter tool, including name, description, and input schema with enum validation.

  name: "recency_filter",
  description: "Control the time window for search results. Essential for time-sensitive queries like news, updates, or recent developments. Filter persists until changed.",
  inputSchema: {
  	type: "object",
  	properties: {
  		filter: {
  			type: "string",
  			enum: ["hour", "day", "week", "month", "none"],
  			description: "Time window: 'hour' for breaking news, 'day' for daily updates, 'week' for recent developments, 'month' for broader recent context, 'none' to include all time periods",
  		},
  	},
  	required: ["filter"],
  },

• src/server/PerplexityMcpServer.ts:116-135 (registration)

  Registration of tool handlers in the MCP server's CallToolRequest handler, dispatching recency_filter to RecencyFilterHandler.handle()

  	switch (request.params.name) {
  		case "search":
  			return this.searchHandler.handle(request);
  		case "domain_filter":
  			return this.domainFilterHandler.handle(request);
  		case "recency_filter":
  			return this.recencyFilterHandler.handle(request);
  		case "clear_filters":
  			return this.filterManagementHandler.handleClearFilters();
  		case "list_filters":
  			return this.filterManagementHandler.handleListFilters();
  		case "model_info":
  			return this.modelInfoHandler.handle(request);
  		default:
  			throw new McpError(
  				ErrorCode.MethodNotFound,
  				`Unknown tool: ${request.params.name}`
  			);
  	}
  });

• src/server/PerplexityMcpServer.ts:83-83 (registration)

  Instantiation of RecencyFilterHandler instance in PerplexityMcpServer constructor.

  this.recencyFilterHandler = new RecencyFilterHandler(this.filterState);

• src/models/FilterState.ts:55-70 (helper)

  FilterState.setRecencyFilter method, which stores the recency filter value and generates the response message used by the handler.

  setRecencyFilter(filter: string): string {
  	if (filter === "none") {
  		this.recencyFilter = null;
  		return "Recency filter has been disabled. Searches will include results from any time period.";
  	}
  
  	this.recencyFilter = filter;
  	const timeDescription = {
  		hour: "hour",
  		day: "24 hours", 
  		week: "7 days",
  		month: "30 days"
  	}[filter] || filter;
  
  	return `Recency filter set to "${filter}". Searches will be limited to content from the last ${timeDescription}.`;
  }