Developer releases 'latch', a Python library to prevent LLM agents from duplicate charges

A developer has released an open-source Python library called 'latch' to address a recurring problem where LLM agents retry tool calls unnecessarily, leading to duplicate charges, emails, or orders. The issue arises because agent client-side timeouts can abandon a call that is still running in the background, causing both the original and the retry to execute. The fix applies the long-established concept of idempotency keys — standard practice in backend systems like Stripe — to the specific context of agent tool-calling. The library is pip-installable, requires no additional dependencies, and offers a simple decorator that ensures a function executes only once per unique idempotency key. Beyond idempotency, 'latch' also includes decorators for circuit breaking, timeouts, and budget guardrails to make agent tool calls more resilient.