AI · alternatives · 2026
24 alternatives to Defend
Open-source guardrails for LLM apps
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
- 1
Hi HN, I'm Antoine Zambelli, AI Director at Texas Instruments. I built Forge, an open-source reliability layer for self-hosted LLM tool-calling. What it does: - Adds domain-and-tool-agnostic guardrails (retry nudges, step enforcement, error recovery, VRAM-aware context management) to local models running on consumer hardware - Takes an 8B model from ~53% to ~99% on multi-step agentic workflows without changing the model - just the system around it - Ships with an eval harness and interactive dashboard so you can reproduce every number I wanted to run a handful of always-on agentic systems…
May 2026 · github.com · its alternatives →
- 2
Lakera Guard▲131Protect your LLM applications with a few lines of code.
2023 · lakera.ai · its alternatives →
- 3
- 4
Open sourced application to detect security vulnerabilities.
2020 · github.com · its alternatives →
- 5
Shieldstral▲104Define safety at runtime for text and images
Aug 2026 · mistral.ai · its alternatives →
- 6
GuardRails▲66Continuous security feedback for your repositories.
2020 · guardrails.io · its alternatives →
- 7
Open safety reasoning models with custom safety policies
Oct 2025 · openai.com · its alternatives →
- 8
Fast and adaptive security guardrail for AI agents
2025 · guardion.ai · its alternatives →
- 9
Configurable safety control for enterprise agent deployment.
Apr 2026 · elevenlabs.io · its alternatives →
- 10
Breadcrumb▲163Open-source LLM tracing for agent visibility
Mar 2026 · breadcrumb.sh · its alternatives →
- 11
An information-flow policy engine for LLM agents.
24d ago · openappa.com · its alternatives →
- 12
Prompt-injection firewall for prod LLM apps
Jul 2026 · insightits.com · its alternatives →
- 13
- 14
MCP Defender▲152Hi HN, MCP Defender is an open source desktop app that automatically proxies your MCP traffic in AI apps like Cursor, Claude, Windsurf and VSCode. It then scans all requests and responses between the apps and the MCP tools they call. If it detects anything malicious, it alerts you and lets you allow or block the tool call. While the threat landscape of MCP is still being actively researched, there are dangerous things that MCP Defender can block today. For example, a developer asks Cursor to fix a Github issue with an attached crash log. However, the Github issue was created by an attacker…
2025 · mcpdefender.com · its alternatives →
- 15
Defend your organization's security, by attacking it
2021 · originhq.com · its alternatives →
- 16OS
2024 · defguard.net · its alternatives →
- 17
An open source Next app template to monitor your AI apps
2025 · github.com · its alternatives →
- 18FL
Hi HN! We just launched Codacy Guardrails, an IDE extension with a CLI for code analysis and MCP server that enforces security & quality rules on AI-generated code in real-time. It hooks into AI coding assistants (like VS Code Agent Mode, Cursor, Windsurf), silently scanning and fixing AI-suggested code that has vulnerabilities or violates your coding standards, while the code it’s being generated. We built this because coding agents can be a double-edged sword. They do boost productivity, but can easily introduce insecure or non-compliant code. One recent research team at NYU found that 40%…
2025 · its alternatives →
- 19
New ways of breaking app-integrated LLMs . Contribute to greshake/llm-security development by creating an account on GitHub.
2023 · github.com · its alternatives →
- 20
Guardrails and Provenance for enterprise AI control
Mar 2026 · console.agumbe.ai · its alternatives →
- 21
Current AI-assisted CLI tools are often part of larger systems and work better on Linux. I built llm-term to address these. It's a Rust-based tool that compiles into a single binary file. You only need to download the binary, add it to your PATH, and configure your OpenAI key to get started. While llm-term offers an option for gpt-4o, it works great with gpt-4o-mini. So it's not costly. I appreciate any feedback or suggestions.
2024 · github.com · its alternatives →
- 22
TL;DR: we built a framework-agnostic agent runtime that uses gVisor for isolation and runs on k8s. It’s open-source under AGPLv3 Recently we’ve been working on a customer support “AI assistant” - essentially an interactive knowledge base/L1 support but with an option to touch resources that belong to a customer it’s talking to. We found existing tools to be lacking in these aspects: 1. Fully intercepted i/o. We wanted to trace out LLM calls as well as any other networking calls attempted by the harness so that guardrails and audit trails apply to all current and future systems…
Jul 2026 · github.com · its alternatives →
- 23
We build runtime security for AI agents. The playground started as an internal tool that we used to test our own guardrails. But we kept finding the same types of vulnerabilities because we think about attacks a certain way. At some point you need people who don't think like you. So we open-sourced it. Each challenge is a live agent with real tools and a published system prompt. Whenever a challenge is over, the full winning conversation transcript and guardrail logs get documented publicly. Building the general-purpose agent itself was probably the most fun part. Getting it to reliably use…
Mar 2026 · github.com · its alternatives →
- 24
AEGIS▲2Open-source LLM defense that publishes its real bypass rate
Aug 2026 · defenseaegis.org · 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 →