perplexity-reference-architecture

# Perplexity Reference Architecture ## Overview Production architecture for AI-powered search with Perplexity Sonar API. Three tiers: search service (model routing + caching), citation pipeline (extract, validate, store), and research orchestrator (multi-query synthesis). ## Architecture ``` ┌─────────────────────────────────────────────┐ │ Application Layer │ │ (Search Widget, Research Agent, Fact Check) │ └──────────────────────┬──────────────────────┘ │ ┌──────────────────────▼──────────────────────┐ │ Search Service Layer │ │ ┌──────────┐ ┌──────────┐ ┌─────────────┐ │ │ │ Model │ │ Query │ │ Response │ │ │ │ Router │ │ Cache │ │ Parser │ │ │ └──────────┘ └──────────┘ └─────────────┘ │ └──────────────────────┬──────────────────────┘ │ ┌──────────────────────▼──────────────────────┐ │ api.perplexity.ai/chat/completions │ │ sonar | sonar-pro | sonar-reasoning-pro │ └─────────────────────────────────────────────┘ ``` ## Prerequisites - Perplexity API key with Sonar access - OpenAI-compatible client library (`openai` package) - Redis for production caching (LRU for development) ## Instructions ### Step 1: Search Service with Model Routing ```typescript // src/perplexity/search-service.ts import OpenAI from "openai"; import { createHash } from "crypto"; type SearchDepth = "quick" | "standard" | "deep" | "reasoning"; const MODEL_MAP: Reco...