Retained PTC processes follow file policy
保留状态的 PTC 进程遵循文件策略
Retaining JavaScript variables does not require broader file access. A process that outlives one execution can also outlive a one-time approval or a Session policy change. File-policy changes must invalidate retained environments and begin stopping their file handles and background work.
English
Problem
Retaining JavaScript variables does not require broader file access. A process that outlives one execution can also outlive a one-time approval or a Session policy change. File-policy changes must invalidate retained environments and begin stopping their file handles and background work.
Decision
persistent-in-memory starts its Node process through the same sandbox provider as per-call. A retained owner uses one resolved mode, workspace root and Session identity until release. The memory decision owns retained values, failure recovery and package composition; this note owns file authority.
The PTC-owned cleanup decision supersedes this note’s permission-setter completion and cleanup-ownership decision. Permission changes commit synchronously; PTC owns immediate cancellation and waits internally before subsequent execution. The tools package keeps Agent ownership and omits the owner for temporary escalations.
An approved one-time escalation omits the state owner and receives a fresh temporary environment. Its process is released before the call returns. It cannot access standing variables, and its declarations do not survive. The standing environment keeps its original policy and variables. Nested tools continue to apply their own permissions and approvals.
Alternatives considered
Unconfined retained execution. Omitting confinement simplifies a temporary prototype but couples variable retention to full host file access. The existing process sandbox supports long-lived processes, so this grant is unnecessary.
Changing the running process policy. Existing backends apply restrictions at launch. Arbitrary retained objects, open handles and background work cannot be transferred into another policy with the existing interface. Releasing the environment prevents later evaluations from reusing those resources.
Coordinating through permission presets. File-policy changes also have direct callers. PTC observes committed Session mode events from both paths, independently of user-facing preset selection.
Keeping an elevated environment. A one-time approval cannot authorize future programs or idle background work. Omitting the state owner makes the approval lifetime explicit while preserving the standing environment.
Consequences
Normal calls retain variables without changing file permissions. Changing sandbox mode discards variables. Escalated programs must be self-contained. Runtime consumers must release a retained owner before supplying a different policy without a Session mode change; the provider rejects inconsistent reuse. The sandbox inherits the existing backends’ file-effect coverage and platform limitations.
中文
问题
保留 JavaScript 变量不需要更大的文件访问权限。跨调用存活的进程也可能在单次审批结束或 Session 策略变化后继续运行。文件策略变化必须使保留环境失效，并开始停止其文件句柄和后台工作。
决策
persistent-in-memory 与 per-call 通过同一个沙箱提供方启动 Node 进程。保留状态的所有者在释放前使用固定的已解析权限模式、工作区根目录和 Session 身份。内存决策负责保留值、失败恢复和包组成；本文负责文件权限。
PTC 自行等待清理的决策替代本文关于权限设置完成时点和清理归属的决策。权限变化同步提交；PTC 负责立即取消，并在后续执行前内部等待清理。工具包保留 Agent 所有权，在临时提权时省略所有者。
单次获准的提权省略状态所有者，使用全新的临时环境。该次调用返回前释放进程，无法访问原环境的变量，也不会保留新声明。原环境保持原权限和变量。嵌套工具继续应用各自的权限和审批规则。
考虑过的替代方案
不限制保留状态的执行环境。 省略沙箱能简化临时原型，却把变量保留与完整宿主文件访问权限绑定。现有进程沙箱支持长期运行的进程，因此这项授权没有必要。
修改运行中进程的策略。 现有后端在启动时应用限制。现有接口无法把任意保留对象、打开的句柄和后台工作转移到另一策略。释放环境可以防止后续执行复用这些资源。
通过权限预设协调清理。 文件策略也有直接调用方。PTC 观察两类调用方提交的 Session 模式事件，无需依赖面向用户的预设选择。
保留提权环境。 单次审批不能授权未来程序或空闲期间的后台工作。省略状态所有者明确了审批生效的范围，同时保留原环境。
影响
普通调用保留变量，同时维持原文件权限。切换沙箱模式会丢弃变量。提权程序必须包含执行所需的完整代码。未发生 Session 模式变化时，运行时消费者在传入不同策略前必须释放保留状态的所有者；提供方拒绝策略不一致的复用。沙箱继承现有后端的文件约束范围与平台限制。