Lite-Harness SDK

AI harnesses are the new vendor lock-in. To swap across harnesses easily without rewriting your app, LiteLLM launched the Lite-Harness SDK . Run your prompt across different harnesses: from lite_harness import query , AgentOptions prompt = " Fix the failing test " # Claude Code harness async for message in query ( prompt = prompt , options = AgentOptions ( harness = " claude-code " , model = " claude-opus-4-8 " ), ): print ( message ) # Codex harness async for message in query ( prompt = prompt , options = AgentOptions ( harness = " codex " , model = " gpt-5.5 " ), ): print ( message ) To enable cost controls, fallbacks, and logging, point it to your LiteLLM AI Gateway: export LITELLM_API_BASE = https://litellm.your-company.com/v1 export LITELLM_API_KEY = sk-litellm-... Engineer's Takeaway: This SDK unifies how you invoke the agents, not how they run internally. Each harness keeps its native loop and tool-calling semantics. It is perfect for A/B testing agent performance and centralizing costs, but remember it is in public beta, so custom tool injection might require extra work! The Problem I Had My team was building an internal bot to fix failing CI/CD tests. We had three engineers advocating for three different harnesses: one wanted Claude Code, another Codex, and another Pi AI. Without an abstraction layer, we would have had to maintain three forks of the same bot , with three different SDKs, three logging systems, and three ways to track costs. It would have been an impossible maintenance burden. How Lite-Harness Helped The SDK solved that exact pain point in three concrete dimensions : 1. Unified Invocation (Time Savings) Instead of maintaining three separate implementations, I had a single query() that routed to whichever harness I wanted. Switching from Claude Code to Codex was literally just changing a string in the options. This allowed us to do real A/B testing in production for two weeks without rewriting any core logic. 2. Cost Observability (The Killer