AI21 Labs releases Teel Python runtime library

AI21 Labs has released Teel, an open-source Python runtime library designed to overlap independent IO-bound calls in sequential code using a shadow interpreter that reads ahead through bytecode. Operating via decorators like @cacheable and @jit, Teel dispatches known-argument calls on background threads without requiring manual async programming. In benchmarks, the tool achieved significant runtime reductions on Princeton's Tree of Thoughts and outperformed async JavaScript implementations within LangChain's Deep Agents. Open article →