Agent Evals, Guardrails & Spend Caps in Production

Defense-in-Depth for Public AI Endpoints

Every public AI route needs three guardrails before going live: per-IP/session rate limiting, strict max_tokens bounds, and provider-level hard spend caps.

export function enforcePromptBudget(prompt: string, maxChars = 4000) {
  if (prompt.length > maxChars) {
    throw new Error(`Prompt exceeds maximum allowed length of ${maxChars} characters.`);
  }
  return prompt.trim();
}

Production Architecture Takeaway

Validate input length and token budgets at the Cloudflare Worker edge before forwarding any request to an upstream LLM or GPU provider.