Silmaril
Security for agents that self-improves
Silmaril is an AI firewall that wraps inference calls to block harmful outcomes before they occur. It evaluates the agent's complete trajectory against the user's task, covering indirect prompt injection, unauthorized tool use, toxic MCP and tool sequences, memory poisoning, cross-agent propagation, data exfiltration, supply-chain compromise, malware execution, and destructive actions.
The firewall uses a low-latency classifier that reads intent, application context, and execution state as a single signal, blocking risky user intent, tool calls, context, and accumulated state in real time. Autonomous agents probe the product through the UI to find vulnerabilities, and each discovered attack becomes synthetic training data that updates defenses. Integration is via a small SDK wrapper across major agent stacks, with language SDKs, agent plugins, frameworks, and AI gateways, plus managed or self-hosted controls and node-level blocking. It works with tools including Codex, Claude Code, GitHub Copilot, Cursor, Gemini CLI, Windsurf, Cline, OpenCode, OpenClaw, and Hermes.
Silmaril is aimed at teams running AI agents in production. The pages describe a briefing and a call booking as the way to get started, without stating a free plan, trial, or pricing structure.
12 alternatives to Silmaril
Ranked by how well each tool replaces Silmaril: shared features, audience, price and popularity.
Agentic AI security platform covering API discovery, posture management, and runtime threa
Covers 6 of 10 key features.
63 out of 100 match—AI-powered next-gen SIEM for cloud-first environments
Covers 5 of 10 key features.
63 out of 100 matchContact sales- 62 out of 100 matchContact sales
- 62 out of 100 matchContact sales
The leading security platform to secure your AI future
Covers 5 of 10 key features and has a free plan.
Free plan62 out of 100 matchContact salesA SUID program that restricts the running environment of untrusted applications using the
Covers 6 of 10 key features, has a free plan and is open source.
Free planOpen source61 out of 100 matchContact sales- 61 out of 100 matchContact sales
AI-native cybersecurity platform protecting endpoints, cloud, identity and AI tools
Covers 4 of 10 key features.
61 out of 100 matchContact salesThe AI operating system for end-to-end third-party cyber risk management
Covers 4 of 10 key features and has a free plan.
Free plan61 out of 100 matchContact salesAI-Reinforced SIEM Solutions Platform for Advanced Cybersecurity Operations
Covers 6 of 10 key features.
60 out of 100 match—Secure AI. Fearless Innovation.
Covers 2 of 10 key features and has a free plan.
Free plan60 out of 100 matchFree
