Infisical

Editorial note

Infisical is a secrets manager first: a central place for API keys, database credentials and config, with versioning, rotation, dynamic short-lived credentials, a Kubernetes operator and syncs to platforms like GitHub, Vercel and AWS. It is genuinely open-source and self-hostable, which is the reason to choose it over a managed-only competitor when you have air-gap or data-residency constraints. The feature that earns it a place in this category is Agent Proxy: instead of putting a live API key into an agent's environment or context window — where a successful prompt injection can read it — the agent calls through a proxy that injects the secret just before the request leaves. The agent only ever sees a placeholder, so a compromised agent leaks nothing useful. (The Gemini research that surfaced this tool called the feature "Agent Vault"; the actual name is Agent Proxy.) The cost is operational: self-hosting is another stateful service to run and patch, and the deeper privileged-access features sit on paid tiers.