{"error": {"message": "Invalid API key", "type": "authentication_error", "code": 401}}

set -euo pipefail
# Verify key is set and has correct prefix
echo "${PERPLEXITY_API_KEY:0:5}"  # Should print "pplx-"

# Test key directly
curl -s -o /dev/null -w "%{http_code}" \
  -H "Authorization: Bearer $PERPLEXITY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"sonar","messages":[{"role":"user","content":"test"}],"max_tokens":5}' \
  https://api.perplexity.ai/chat/completions
# 200 = valid, 401 = invalid key

{"error": {"message": "Rate limit exceeded", "type": "rate_limit_error", "code": 429}}

async function withBackoff<T>(fn: () => Promise<T>, maxRetries = 5): Promise<T> {
  for (let i = 0; i <= maxRetries; i++) {
    try {
      return await fn();
    } catch (err: any) {
      if (err.status !== 429 || i === maxRetries) throw err;
      const delay = Math.pow(2, i) * 1000 + Math.random() * 500;
      console.log(`Rate limited. Retrying in ${delay.toFixed(0)}ms...`);
      await new Promise(r => setTimeout(r, delay));
    }
  }
  throw new Error("Unreachable");
}

{"error": {"message": "Invalid model: gpt-4", "type": "invalid_request_error"}}

{"error": {"message": "search_domain_filter must contain at most 20 domains"}}

// Allowlist: only these domains
search_domain_filter: ["python.org", "docs.python.org"]

// Denylist: exclude these domains
search_domain_filter: ["-reddit.com", "-quora.com"]

// BAD: abstract query yields no citations
"Tell me about technology"

// GOOD: specific factual query
"What are the key features of TypeScript 5.5 released in 2025?"

const controller = new AbortController();
const timeout = setTimeout(() => controller.abort(), 15000);

try {
  const response = await perplexity.chat.completions.create(
    { model: "sonar", messages: [{ role: "user", content: query }] },
    { signal: controller.signal }
  );
  return response;
} finally {
  clearTimeout(timeout);
}

{"error": {"message": "Insufficient credits", "type": "billing_error"}}

set -euo pipefail
# Quick API health check
curl -s -w "\nHTTP %{http_code} in %{time_total}s\n" \
  -H "Authorization: Bearer $PERPLEXITY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"sonar","messages":[{"role":"user","content":"ping"}],"max_tokens":5}' \
  https://api.perplexity.ai/chat/completions

# Check if key env var is set
env | grep PERPLEXITY

# Test DNS resolution
dig api.perplexity.ai +short