Your AI agent crashed at step 7. Now what? Meet pylinxi
Production AI agents fail in boring ways, and pylinxi is a small open-source Python library built to make those failures recoverable. Picture a support agent handling a refund. It classifies the ticket with an LLM, looks up the charges, drafts a reply, waits for a manager to approve, then issues the refund. Somewhere around step 4 the container is recycled. Now what? Do you start again from step…
When AI agents crash during production, they often fail in mundane ways. The pylinxi library aims to make those failures recoverable. Imagine a support agent dealing with a refund. It classifies the ticket, looks up the charges, drafts a reply, waits for manager approval, and finally issues the refund. Somewhere around step 4, the container is recycled.
The question arises: should you restart from step 1, incurring double charges for LLM calls, or will the refund API have already run? Will a retry lead to double charges for the customer? The manager clicked "approve" an hour ago, but where is that approval now? Real-world production hits these questions daily: rate limits, malformed JSON from a model, a deploy interrupting a run, or a human replying at a later time.
An agent that can't handle these issues isn't ready for real users, regardless of how well-crafted its prompts are.
This post examines why this matters and how pylinxi addresses it using plain Python instead of a graph framework. While graph frameworks like LangGraph handle durability well, they introduce wiring overhead and state plumbing, which can become cumbersome as workflows grow. Healing in these frameworks typically relies on retries, leaving repairing complex issues to the developer.
In contrast, pylinxi treats the agent as a simple Python function. Each call to a @step is saved to a journal, enabling replay of the function from the last finished step in case of failure. Branching is achieved with if statements, loops with for, and parallelism with asyncio.gather. There's no need to wire a graph, and the durability is retained without the overhead.
To implement self-healing, pylinxi uses policies for each step. The healing process follows these steps: retry, validate, repair, fallback, and circuit breaker. The repair hook allows rewriting the step's inputs before the next attempt. For instance, in the case of LLMs, the actual error can be fed back into the prompt to improve future responses.
Dependencies that go down can be handled by adding fallback mechanisms. By sharing a circuit breaker, you can manage multiple dependencies effectively. This approach ensures that the agent can handle failures gracefully, resuming from the point of failure and avoiding unnecessary rework of successful steps.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
