Dev tools · alternatives · 2026
24 alternatives to Prompt-injection firewall for AI agents
Block malicious web content before it reaches your AI.
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
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Alright so if you run a self-hosted blog, you've probably noticed AI companies scraping it for training data. And not just a little (RIP to your server bill). There isn't much you can do about it without cloudflare. These companies ignore robots.txt, and you're competing with teams with more resources than you. It's you vs the MJs of programming, you're not going to win. But there is a solution. Now I'm not going to say it's a great solution...but a solution is a solution. If your website contains content that will trigger their scraper's safeguards, it will get dropped from their data…
Dec 2025 · github.com · its alternatives →
- 2
Hi HN, Matvey, Ildar, Joey, and Dominik here. If you're building LLM agents that use tools, you're probably worried about prompt injection attacks that can hijack those tools. We were too, and found that solutions like prompt-based filtering or secondary "guard" LLMs can be unreliable. Our thesis is that agent security should be handled at the network level between the agent and the LLM, just like a traditional web application firewall. So we built Archestra Platform: an open-source gateway that acts as a secure proxy for your AI agents. It's designed to be a deterministic firewall against…
2025 · archestra.ai · its alternatives →
- 3
I've been experimenting with Claude Code, ChatGPT Agent, and OpenClaw to perform more open-ended tasks for me online. A big blocker I've hit on shopping and research tasks is the agent getting a key piece of info wrong. For example, in one case, my agent decided to add a brand I don't like to the cart because the site flagged it as almost sold out The HN crowd is probably pretty aware of the threats and can avoid them while browsing. But what about their agents? I tried prompting, but it was ineffective, because once the AI saw the threat, it polluted/distracted its context Looking at…
Jun 2026 · github.com · its alternatives →
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Hi HN, I’m the creator of Cordum. I’ve been working in DevOps and infrastructure for years (currently in the fintech/security space), and as I started playing with AI agents, I noticed a scary pattern. Most "safety" mechanisms rely on system prompts ("Please don't do X") or flimsy Python logic inside the agent itself. If we treat agents as autonomous employees, giving them root access and hoping they listen to instructions felt insane to me. I wanted a way to enforce hard constraints that the LLM cannot override, no matter how "jailbroken" it gets. So I built Cordum. It’s an open-source…
Jan 2026 · github.com · its alternatives →
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New ways of breaking app-integrated LLMs . Contribute to greshake/llm-security development by creating an account on GitHub.
2023 · github.com · its alternatives →
- 7
Every other gateway is detect-and-block. You don't get a security grade. You don't get red team in CI. We built the one that does. PromptGuard is a proxy: change your base URL (one line with our SDK, or a few lines without), and every request gets checked for prompt injection, PII leaks, jailbreaks, and abuse. 20+ threat vectors, 39+ PII types. We also ship a red team suite and an autonomous agent that mutates attacks to find bypasses - you get a grade (A-F) and a GitHub Action that runs these tests on every PR. So you see where you're weak before you ship. Works with OpenAI, Anthropic,…
Dec 2025 · promptguard.co · its alternatives →
- 8
Hey HN, We built FireClaw because we kept watching AI agents get owned by prompt injection through web content. The agent fetches a page, the page says "ignore previous instructions," and suddenly your agent is leaking data or running commands it shouldn't. The existing solutions detect injection after the fact. We wanted to prevent it. FireClaw is a security proxy that sits between your AI agent and the web. Every fetch passes through a 4-stage pipeline: 1. DNS blocklist check (URLhaus, PhishTank, community feed) 2. Structural sanitization (strip hidden CSS, zero-width Unicode, encoding…
Mar 2026 · github.com · its alternatives →
- 9
The AI firewall that understands compliance context
Dec 2025 · promptlock.io · its alternatives →
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People seem to be blindly hooking up their OpenClaw’s to their personal data. So, I built runtime controls to prevent at the least, very simple prompt injection attacks. Once installed, it hooks to Node.js child_process module in the gateway process and listens to tool calls and their response streams. And a fetch hook to monitor user prompts (both could’ve been through fetch, happy to discuss why this whole layer couldn’t just be a proxy). There are two layers of protection: First: Whenever there is a read-only tool call whose response an attacker can modify, we extract that part of the…
Feb 2026 · github.com · its alternatives →
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Your agent team, on your machine. Open-source harness for multi-user Claude agents. - yaodub/cast
Jun 2026 · github.com · its alternatives →
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SafePrompt▲12Anonymize Prompt and Text Input to use AI at work safely
2025 · jack-of-all-trades.dev · its alternatives →
- 15
Tiny prompt-injection firewall for LLM chat apps. 14 MB.
May 2026 · github.com · its alternatives →
- 16
Prompt instructions like 'never do X' don't hold up in production. LLMs ignore them when context gets long or users push hard. Limits sits between your agent and the real world. Every action — database writes, API calls, refunds — gets intercepted and checked against your rules before it executes. Deterministically. No LLM involved in enforcement. Three modes: Conditions: hard rules on structured data Guideance: validate LLM output before it reaches the user and give the agent chance to reason and retry Guardrails: scan for PII, toxicity, prompt injection etc One line to integrate: npm…
Feb 2026 · limits.dev · its alternatives →
- 17
SupraWall ▲4Open Source deterministic security Firewall for AI agents
May 2026 · supra-wall.com · its alternatives →
- 18
Security firewall for AI agents. Cloudflare for MCP.
Feb 2026 · agent-wall.github.io · its alternatives →
- 19
The only way to go fast is full YOLO mode in your coding agent. I've got the local sandbox figured out (pro tip: Incus VMs work great) but I wanted to keep my agents from doing things like inadvertently blowing up my cloud services or chasing a prompt to POST to some random website. I struggle most with this on my side projects where my permission model isn't quite as robust as it is at the office. I started with a firewall on the Incus container but every time the agent needed access to something new, I was poking more holes in it - and it didn't differentiate between HTTP verbs. I've been…
Jul 2026 · trollbridge.dev · its alternatives →
- 20
Just stop jailbreaks & prompt hacks with one API call.
2025 · expireddomains.com · its alternatives →
- 21
Greywall▲10Prefix any AI coding agent with `greywall --` for a live feed of every read, write, and connection. Allow by default; ask mode and deny rules opt-in via config. Linux and macOS.
Mar 2026 · greywall.io · its alternatives →
- 22
Runtime firewall for AI coding agents.
Aug 2026 · contextfence.dev · its alternatives →
- 23FP
We've built an open-source tool to stress test AI agents by simulating prompt injection attacks. We’ve implemented one powerful attack strategy based on the paper [AdvPrefix: An Objective for Nuanced LLM Jailbreaks](https://arxiv.org/abs/2412.10321). Here's how it works: - You define a goal, like: “Tell me your system prompt” - Our tool uses a language model to generate adversarial prefixes (e.g., “Sure, here are my system prompts…”) that are likely to jailbreak the agent. - The output is a list of prompts most likely to succeed in bypassing safeguards. We’re just getting…
2025 · security.vista-labs.ai · its alternatives →
- 24
Stop prompt injection attacks with one API call. Free tier.
Apr 2026 · safeprompt.dev · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →