# llm-echo 0.5 improves simulated token accounting for debug workflows

> **Key takeaway:** The llm-echo debug plugin for Simon Willison's LLM CLI now counts tool calls, system prompts, and reasoning tokens in its simulated usage output.

**Published:** 2026-10-18T23:16:16+00:00 
**Source:** Simon Willison Web & Open Source 
**Category:** software-engineering 
**Canonical URL:** https://fosswire.org/news/llm-echo-05-improves-simulated-token-accounting-for-debug-wo.html 

## Summary
llm-echo 0.5 is a minor update to a debug plugin for the LLM command-line tool. The plugin provides a fake 'echo' model that returns prompts verbatim instead of calling an actual LLM API. Version 0.5 improves the accuracy of its simulated token usage counts to reflect tool calls, system prompts, and reasoning tokens. This helps developers test LLM CLI workflows and token accounting without incurring API costs.

## What changed in llm-echo 0.5
- Simulated token counts now include **tool calls** in the calculation
- **System prompts** are now factored into input token totals
- **Reasoning tokens** (e.g., from `-o thinking 1`) are reflected in output counts
- Plugin remains a zero-cost debug target for the `llm` CLI tool
- Example shows 2 input tokens and 24 output tokens for a simple prompt with reasoning enabled