Best alternatives to Custodian Labs in 2026

Building an AI agent that handles real customer data creates an uncomfortable question most teams solve poorly: what stops a customer's email address or ID number from ending up verbatim in a prompt sent to an external LLM provider? Custodian Labs bakes an answer directly into its SDK — a "Guardian Layer" that automatically detects personal data in text and either masks it, transforms it, or just flags it, depending on how you configure it, before the agent's logic ever touches it. Beyond privacy, it's designed to get a working AI agent running in about five lines of code, with built-in retrieval-augmented generation that doesn't require separately standing up and configuring a vector database, multi-agent routing for handing off tasks between specialized agents, and support for OpenAI, Anthropic, Mistral, or local models interchangeably.