# How AI firewalls protect production applications from prompt injection, data leakage, and excessive usage

DevFeed: [How AI firewalls protect production applications from prompt injection, data leakage, and excessive usage](<https://devfeed.tech/articles/ai-firewall-29071.md>)

Original publisher: [Read original article](<https://blog.alexewerlof.com/p/ai-firewall>)

Author: Alex Ewerlöf

Published: 2026-03-15T23:51:29Z

Content type: tutorial

Language: en

Sources: [Alex Ewerlof Notes](<https://devfeed.tech/sources/alex-ewerlof-notes.md>)

Topics: [Firewall](<https://devfeed.tech/topics/firewall.md>), [Security](<https://devfeed.tech/topics/security.md>), [prompt injection](<https://devfeed.tech/topics/prompt-injection.md>), [LLMs](<https://devfeed.tech/topics/llms.md>), [rate-limiting](<https://devfeed.tech/topics/rate-limiting.md>), [pii](<https://devfeed.tech/topics/pii.md>)

Tags: [architecture](<https://devfeed.tech/tags/architecture.md>), [firewall](<https://devfeed.tech/tags/firewall.md>), [llms](<https://devfeed.tech/tags/llms.md>), [pii](<https://devfeed.tech/tags/pii.md>), [prompt-injection](<https://devfeed.tech/tags/prompt-injection.md>), [rate-limiting](<https://devfeed.tech/tags/rate-limiting.md>), [security](<https://devfeed.tech/tags/security.md>)

## AI overview

This tutorial explains AI firewalls, or AI gateways, as reverse proxies with AI-focused inspection between an application backend and an inference provider. It covers ingress attacks such as prompt injection, egress risks including PII and secrets, rate limiting to control costs, latency considerations, implementation trade-offs, and layered defenses.

## Source excerpt

How to protect your AI application in production against new classes of attacks