Simon Willison · · 1 min read

llm-echo 0.5a0

Mirrored from Simon Willison for archival readability. Support the source by reading on the original site.

5th May 2026

Release llm-echo 0.5a0 — Debug plugin for LLM providing an echo model
  • New -o thinking 1 option to help test against LLM 0.32a0 and higher.

This plugin provides a fake model called "echo" for LLM which doesn't run an LLM at all - it's useful for writing automated tests. You can now do this:

uvx --with llm==0.32a1 --with llm-echo==0.5a0 llm -m echo hi -o thinking 1

This will fake a reasoning block to standard error before returning JSON echoing the prompt.

Posted 5th May 2026 at 1:31 am

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