# Honor temperature=0 on Claude for deterministic output

> Claude on Anthropic, AWS, and VertexAI used to silently drop an explicit 0 for temperature, top_p, or top_k, since a bare truthiness check treated 0.0 as unset and fell back to the API default near…

- Published: 2026-05-21
- Author: Agno Team
- Category: Changelog
- Canonical: https://agno-com-nine.vercel.app/articles/honor-temperature-0-on-claude-for-deterministic-output
- Markdown: https://agno-com-nine.vercel.app/articles/honor-temperature-0-on-claude-for-deterministic-output.md

Claude on Anthropic, AWS, and VertexAI used to silently drop an explicit `0` for `temperature`, `top_p`, or `top_k`, since a bare truthiness check treated `0.0` as unset and fell back to the API default near 1.0. Agno now checks `is not None`, so setting any of these to `0` produces the deterministic output you asked for instead of quietly reverting to a random one.