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llm-echo 0.5

Simon Willison · Oct 18, 2026 · Engineering Insights

llm-echo debug plugin updated to simulate tool calls and reasoning token counts

Simon Willison released llm-echo 0.5, a debug plugin for his LLM CLI tool that simulates model responses without calling a real LLM. The update adds simulated token counting for tool calls, system prompts, and reasoning tokens. Minor tooling update with limited broader industry signal.

llm developer-tools debugging token-usage

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