OpenRouter launched the Armor beta, intercepting agent rule-violating tool calls before execution

OpenRouter launched the Armor beta, inserting a classifier between the model and the user's application that judges each model tool call before deciding whether to allow or block it. Rules are written in natural language in plain English, divided into hard_deny, soft_deny, and allow categories; calls hitting hard_deny are always blocked and cannot be allowed, while soft_deny can be lifted by allow rules or explicit user requests in the conversation. Armor implements a Claude Code-compatible API, and when reasoning through OpenRouter's Ori metaharness, enabling Claude Code auto mode requires no additional configuration; blocked calls are returned to the model with the triggering rule, and the model rewrites the call or explains to the user.