Perplexity MCP Server. ref: https://github.com/jsonallen/perplexity-mcp/blob/bf2bbf866d1c73f4d635c42246da0fe2e57be1af/src/perplexity_mcp/server.py

perplexity-mcp.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

require "mcp"
require "json"
require "net/http"

name "perplexity-mcp"
version "0.1.0"

# Check for API key
api_key = ENV["PERPLEXITY_API_KEY"]
unless api_key
  warn "Error: PERPLEXITY_API_KEY environment variable is required"
  exit 1
end

# Get the model from environment variable or use "sonar" as default
model = ENV["PERPLEXITY_MODEL"] || "sonar"

# Log which model is being used (helpful for debug)
warn "Using Perplexity AI model: #{model}"

# List available models
available_models = {
  "sonar-deep-research" => "128k context - Enhanced research capabilities",
  "sonar-reasoning-pro" => "128k context - Advanced reasoning with professional focus",
  "sonar-reasoning" => "128k context - Enhanced reasoning capabilities",
  "sonar-pro" => "200k context - Professional grade model",
  "sonar" => "128k context - Default model",
  "r1-1776" => "128k context - Alternative architecture"
}

warn "Available Perplexity models (set with PERPLEXITY_MODEL environment variable):"
available_models.each do |model_name, description|
  marker = model_name == model ? "→" : " "
  warn " #{marker} #{model_name}: #{description}"
end

# Define a resource template for prompts
resource_template "prompt://perplexity_search_web/{query}/{recency}" do
  name "perplexity_search_web"
  description "Search the web using Perplexity AI and filter results by recency"
  mime_type "text/plain"
  call do |args|
    query = args[:query]
    recency = args[:recency] || "month"
    
    <<~TEXT
      Find recent information about: #{query}
      Only include results from the last #{recency}
    TEXT
  end
end

# Define a search tool
tool "perplexity_search_web" do
  description "Search the web using Perplexity AI with recency filtering"
  argument :query, String, required: true, description: "The search query to find information about"
  argument :recency, String, required: false, description: "Filter results by how recent they are. Options: 'day' (last 24h), 'week' (last 7 days), 'month' (last 30 days), 'year' (last 365 days). Defaults to 'month'."
  
  call do |args|
    query = args[:query]
    recency = args[:recency] || "month"
    
    # Call Perplexity API
    uri = URI("https://api.perplexity.ai/chat/completions")
    http = Net::HTTP.new(uri.host, uri.port)
    http.use_ssl = true
    
    payload = {
      model: model,
      messages: [
        { role: "system", content: "Be precise and concise." },
        { role: "user", content: query }
      ],
      max_tokens: "512",
      temperature: 0.2,
      top_p: 0.9,
      return_images: false,
      return_related_questions: false,
      search_recency_filter: recency,
      top_k: 0,
      stream: false,
      presence_penalty: 0,
      frequency_penalty: 1
    }
    
    request = Net::HTTP::Post.new(uri)
    request["Authorization"] = "Bearer #{api_key}"
    request["Content-Type"] = "application/json"
    request.body = payload.to_json
    
    response = http.request(request)
    
    if response.is_a?(Net::HTTPSuccess)
      data = JSON.parse(response.body)
      data["choices"][0]["message"]["content"]
    else
      "Error: Failed to get response from Perplexity API (#{response.code})"
    end
  end
end