Modern infrastructure depends on externally maintained artifacts such as package-registry dependencies, CI/CD actions, container images, Terraform providers and modules, developer extensions, model artifacts, and AI tool servers. These artifacts are easy to fetch but difficult for institutions to admit, govern, and revoke. This paper proposes the Custody Envelope Threshold, an authority-scaled model of artifact admission. It argues that direct institutional admission is defensible only when object identity, ingress path, and revocation capacity are sufficiently closed relative to the execution authority delegated to the artifact. When this threshold is not met, institutions tend to proxy, policy-mediate, vendor-mediate, internalize, quarantine, or reject the artifact. The framework is operationalized as a four-condition ordinal instrument and connected to reference-monitor reasoning, least privilege, and transaction cost economics. It is applied to package dependencies, GitHub Actions, container images, Terraform providers and modules, developer extensions, and open model artifacts, with Model Context Protocol (MCP) servers treated as held-out evidence. The paper also specifies a validation design, deterministic prediction function, and OSF replication package for testing whether high-scrutiny institutions converge toward stronger custody closure for high-authority artifacts.

翻译：现代基础设施依赖外部维护的构件，如包注册中心依赖项、CI/CD操作、容器镜像、Terraform提供程序与模块、开发者扩展、模型构件以及AI工具服务器。这些构件易于获取，但机构在准入、治理与撤销方面面临困难。本文提出保管包围阈值，一种权限弹性构件准入模型。论证表明，只有当对象标识、入口路径与撤销能力相对于委托给构件的执行权限充分闭合时，直接机构准入才具有可辩护性。若未达到该阈值，机构倾向于对构件进行代理、策略中介、供应商中介、内部化、隔离或拒绝。该框架被操作化为四条件序数量具，并与引用监控推理、最小权限原则及交易成本经济学相关联。它被应用于包依赖项、GitHub Actions、容器镜像、Terraform提供程序与模块、开发者扩展及开放模型构件，其中模型上下文协议（MCP）服务器作为保留验证集。本文还设计了验证方案、确定性预测函数及OSF复现包，用于检验高审查机构是否倾向于对高权限构件实现更强的保管闭合。