Reasoning is signed: building a universal LLM gateway hits encrypted CoT walls
respan-81 · reddit · 2026-10-27
A developer building respan-gateway — an open-source Rust binary aiming to be the most compatible LLM gateway (any model, any modality, server-side tools and MCP servers) — shares two details where reasoning doesn't transfer between OpenAI, Claude, and Gemini:
- Effort doesn't translate across vendors.
- Reasoning is signed: Claude and Gemini 3 return encrypted reasoning only they can read. Gemini 3 returns a 400 if a tool call in the current turn comes back without its signature, and many OpenAI-style clients drop the field containing it.
The author uses Google's documented placeholder code (request passes, but Gemini's reasoning is lost), and notes LiteLLM's trick of hiding the signature inside the tool call id — a field every client sends back — to preserve it.
More from coding & agent
- Batch-editing hundreds of drone videos by scripting DaVinci Resolve with Astra — sethlazar · 2026-10-27
- DeepSeek V4.1 Flash lands in Cursor, dominating the cost frontier at $0.60-$0.98 per task — dean_rie · 2026-10-27
- Masking slides for AI: placeholders that survive the model but break the layout — shoumikgoswami · 2026-10-27
- Creator has Claude edit her iPhone Duo review inside Tella's agent video editor — evielync · 2026-10-27
- Ant International and Westlake University release Trajectory2Gym for tool-use agent training — ant-intl · 2026-10-27
- Eight universities propose unified framework for work agents — Zishan Xu · 2026-10-27