Simon Willison's `llm` library releases alpha with a backwards-compatible refactor (0.32a0)

What changed

The LLM library released version 0.32a0 in alpha, a significant refactor that maintains backwards compatibility while restructuring the internals beyond a single prompt-response model. The change adds a cleaner model abstraction and updates the CLI to support the new capabilities for testing prompts and running automated tasks from the terminal.

Why it matters

If you embed LLM in custom Python tooling, the new abstraction lets you swap between local and cloud providers without rewriting your codebase. The refactor sets a more stable foundation for state management and structured interactions, which is where most production integrations actually break. Backwards compatibility means you can adopt incrementally rather than rewriting.

What to watch for

Update a dev environment to the alpha and run your existing scripts against it before pinning. Read the changelog for any subtle changes to underlying API call shapes that might affect custom plugins. Test latency and throughput against your current pinned version, especially if you depend on streaming. If the alpha holds up over the next few weeks, plan the upgrade before the stable 0.32 ships and downstream plugin authors fragment.