# Hidden Mode Switching

> Silently routing users to a cheaper model without telling them — eroding trust and making debugging impossible.

- **Category**: Agentic AI
- **Subcategory**: Anti-Patterns
- **Canonical URL**: https://designpattern.fyi/patterns/hidden_mode_switching/

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## Description
**Intent**: Routing some traffic to a smaller/cheaper model to manage cost — without disclosing which model produced any given response.

**Context**: Cost and capacity pressure push teams to mix flagship and smaller models in the backend. Nothing in the response, UI, or trace reveals the actual model used. Users discover the swap from degraded quality, not from you.

**Solution**: Disclose model identity per response. Make routing decisions inspectable in traces and operator dashboards. Use multi-model-routing transparently.



## Use Cases
- Never use this; silent routing of model changes undermines reproducibility and trust.
- Use multi-model-routing transparently, with the resolved model identity disclosed per response.
- Make routing decisions inspectable in traces and operator dashboards.






## Trade-offs




### Considerations & Drawbacks

- Trust erodes when users notice quality shifts and you have no explanation to give

- Reproducibility breaks — identical requests return different quality across calls

- Eval results become misleading because you can''t tell which model you''re measuring







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**Reference**: [Original Source](https://www.agentpatternscatalog.org/patterns/hidden-mode-switching/)