OnceOnly
Control layer for AI agents.
OnceOnly is a control layer that sits between AI agents and the tools they call. It evaluates each request before execution, allowing, deduplicating, or blocking calls based on policy rules, idempotency keys, and spend limits. This addresses duplicate side effects from retries, runaway loops that accumulate tool costs, and unsafe tool usage such as unapproved data exports.
Core capabilities include atomic idempotency keys, policy checks for allowed and blocked tools, daily spend caps, action and per-tool call limits, execution leases for coordinating long-running jobs, and signed tool dispatch. OnceOnly provides Python and TypeScript SDKs, works with LangChain and CrewAI, and records decision trails with logs, metrics, and audit history. It supports email notifications, policy templates, tool pricing rules, and a kill switch for disabling agents.
OnceOnly is aimed at teams running agents that interact with payment systems, customer data, or paid research tools. It is available in a free plan, a Starter plan, and Pro and Agency editions, with monthly billing. Plans differ in AI request volume, governed tool limits, policy depth, observability, and retention periods.
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