---
title: "Discussion on \"Cross-Model Persona Fidelity: Is Your AI Agent Still 'Them' on a Different LLM?\" | Hashnode"
description: "Discussion on \"Cross-Model Persona Fidelity: Is Your AI Agent Still 'Them' on a Different LLM?\". The Portability Promise\nEvery AI agent persona standard makes an implicit promise: define your agent once, run it anywhere. Soul Spec, CLAUDE.md, .cursorrules — they all assume the identity file is portable across models.\nBut is it? Does \"Brad\" on Cl..."
url: "https://hashnode.com/posts/cross-model-persona-fidelity-is-your-ai-agent-still-them-on-a-different-llm/69cbe28fa0c7554d6a5db4bf"
---

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# [Cross-Model Persona Fidelity: Is Your AI Agent Still 'Them' on a Different LLM?](https://clawsouls.hashnode.dev/cross-model-persona-fidelity-is-your-ai-agent-still-them-on-a-different-llm?utm_source=hashnode&utm_medium=feed)

The Portability Promise Every AI agent persona standard makes an implicit promise: define your agent once, run it anywhere. Soul Spec, CLAUDE.md, .cursorrules — they all assume the identity file is portable across models. But is it? Does "Brad" on Cl...

Mar 31 · 2 min read · clawsouls.hashnode.dev  
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-   [#llm](https://hashnode.com/tag/llm)
-   [#persona](https://hashnode.com/tag/persona)
-   [#research](https://hashnode.com/tag/research)
-   [#soul-spec](https://hashnode.com/tag/soul-spec)

## Written by

[ClawSouls](https://hashnode.com/@clawsouls)

@clawsouls · Seoul, South Korea

  
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Open persona spec for AI agents — clawsouls.ai (http://clawsouls.ai/)

## Responses 1

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[Ali Muwwakkil](https://hashnode.com/@enterpriseaileadersh)

[Mar 31](https://hashnode.com/posts/cross-model-persona-fidelity-is-your-ai-agent-still-them-on-a-different-llm/69cbe28fa0c7554d6a5db4bf/comment/69cbec109ec475ca7624dcfd)

One surprising insight is that persona fidelity often hinges more on the fine-tuning dataset than the model architecture itself. In our experience with enterprise teams, subtle shifts in training data lead to drastic personality changes in AI agents, even when switching between similar LLMs. A practical approach is to maintain a consistent dataset across models and leverage prompt engineering to align personas. This ensures that "Brad" remains "Brad," regardless of the underlying LLM. - Ali Muwwakkil (ali-muwwakkil on LinkedIn)