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write.file.host
Change any file the account can reach. Verb write, object file, reach host, family filesystem. Its effect is with-effort: undone at a cost.
In 6 of 9 published shapes
| Deployment shape | Barrier there | Known by | Note | |
|---|---|---|---|---|
| ● | Claude Code on the web (a remote session container) | none (not a control) | observed | a zero-byte file was created and removed in /etc: system configuration of the container is writable |
| ● | Claude Code (the CLI, on your own machine) | none (not a control) | derived | |
| ● | Claude Code (the CLI, on your own machine) | none (not a control) | derived | |
| ◐ | Claude Desktop (a desktop app with local tools) | setting (not a control) | derived | |
| ● | A scheduled job running as a service account | none (not a control) | derived | |
| ● | Actions runner (a hosted CI job) | none (not a control) | observed | the runner's user with passwordless escalation: every file on the ephemeral machine |
| Barrier | What stands in the way | Is it a control | |
|---|---|---|---|
| ● | none | nothing in the way | no |
| ◉ | expectation | a rule in prose, enforced by nobody | no |
| ◐ | setting | a switch the agent's own account can flip | no |
| ○ | boundary | enforced above the grant, out of the agent's reach | yes |
What the starting mandates say about it
| The mandate says | Which mandates |
|---|---|
| authorised | none |
| refused | A coding assistant on my machine, The desktop app, with local tools switched on, Chat in the browser, nothing connected |
| unstated | A coding assistant in a container on the web, Chat, with connectors switched on, A CI job on a hosted runner, A browser extension I installed, A scheduled job under a service account |
Unstated is not authorised. A mandate that never mentioned a capability did not authorise it, and the delta on every example page counts it as excess and says which kind it was.
What would move it to the fourth barrier
| What | What it costs | The barrier afterwards |
|---|---|---|
| the same container or account; the tool's own directory restriction is a setting anything running as you can step around | as above | boundary |
This is a published reduction, not a recommendation. Whether it is worth doing depends on the assets and the consequences, which are not in this document and are not this site's to guess.