Dev Builds Local AI Agent Firewall Using Mistral's Shieldstral
max_paperclips · x · 2026-08-06
A developer built a local Agent firewall experiment using Mistral's newly released 3B open-weights safety model, Shieldstral.
The firewall aims to mitigate security threats in the AI agent loop by inspecting three key stages:
- User input
- Tool outputs (files, terminal, PDFs, images, web content, and AGENTS.md)
- Final response
The author tested the setup against prompt injections, jailbreaks, and hidden instructions in PDFs and images using prompts from the L1B3RT4S repository. They argue that agent firewalls could become just as crucial as agent sandboxes.
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