Best AI Security Software for OpenCode

HOL Guard is a security layer designed for AI agents that operates on a local-first basis, monitoring the actions of an AI assistant and preemptively preventing potentially harmful activities. It functions as an intermediary between the agent and the computer, assessing tool calls and local resources for various threats, including the risk of secret and credential leaks, harmful commands, actions driven by prompt injection, and the use of compromised or altered packages, as well as risky configurations and unsafe plugins, skills, hooks, and settings. Threats that are identified can be automatically blocked, while uncertain actions are temporarily halted to seek user consent, ensuring that individuals maintain oversight. Operating entirely on the developer’s local machine, Guard does not require an internet connection and refrains from uploading any files, prompts, or sensitive information. Local evaluations are typically completed in less than 50 milliseconds, and the implementation of Guard does not necessitate modifications to current code or workflows. It is compatible with various coding agents including Claude Code, Cursor, Codex, Gemini CLI, OpenCode, Hermes, and OpenClaw, providing custom integrations that analyze actions prior to their execution. Additionally, this enhances the overall safety and reliability of AI interactions, fostering greater trust in automated processes.

nono is a novel open-source sandbox that utilizes kernel enforcement to create a secure environment for AI coding agents and LLM tasks. In contrast to traditional policy-based guardrails that merely monitor and filter operations, nono leverages operating system security features—specifically Landlock on Linux and Seatbelt on macOS—to render unauthorized operations impossible at the syscall level. With just a single command, you can encapsulate any AI agent, including Claude Code, OpenCode, OpenClaw, or any command-line interface process. The system automatically enforces a default-deny policy for filesystem access, restricts harmful commands (such as rm, dd, chmod, and sudo), isolates sensitive credentials and API keys, and extends all imposed restrictions to any child processes, ensuring there's no avenue for escape once limitations are set. Built-in profiles allow for rapid deployment, and secrets can be injected from the system keystore in a secure manner, with automatic zeroization upon exit. Additionally, future enhancements such as audit logging, atomic rollbacks, and Sigstore-attested policy signing are planned, offering robust tracking and security features. It operates under the Apache 2.0 license and is developed by the same creator behind Sigstore, further emphasizing its credibility and reliability in securing AI workloads.

Constellation Gate AI serves as an auxiliary defense mechanism for AI agents, positioned strategically between the agent and the model to filter all requests for potential threats and data leaks. This solution functions as an inline gateway for coding agents and model APIs, ensuring protection of workflows while eliminating the need for significant code modifications. Users can direct existing tools such as Claude Code, Cursor, OpenClaw, Codex, or OpenCode to utilize Gate, thereby gaining access to defenses against prompt injection, secret detection, PII redaction, token optimization, and a reliable audit trail. The platform specifically addresses three critical vulnerabilities: prompt injection attacks, leakage of credentials and PII, and unauthorized tool calls. Rather than depending on the model's self-defense mechanisms, Gate preemptively intercepts attacks before they penetrate the model, removes sensitive information prior to the return of responses, and prevents outputs from compromised tools before an agent can act on them. Gate is compatible with the existing calls made by agents, relaying them to the model while meticulously scanning each request and response in both directions, ensuring comprehensive protection against emerging threats. This proactive approach not only enhances security but also instills confidence in users about the integrity and safety of their AI workflows.