interface FilesystemMiddlewareOptionsBackend instance or factory (default: StateBackend)
Optional custom tool descriptions override
Optional token limit before evicting a HumanMessage to the filesystem (default: 50000 tokens, ~200KB)
Filesystem permission rules enforced on every tool call.
Rules are evaluated in declaration order; first match wins; permissive
default. Applies to ls, read_file, write_file, edit_file,
glob, and grep.
Note on execute: permissions are not enforced on execute because
shell commands can access any path regardless of path-based rules. Using
permissions with an execution-capable backend (one where isSandboxBackend
returns true) throws a ConfigurationError unless the backend is a
CompositeBackend and every permission path is scoped to a route prefix.
When omitted or empty, all filesystem operations are permitted.
System prompt override. Set to null to disable. Defaults to ASYNC_TASK_SYSTEM_PROMPT.
Optional token limit before evicting a tool result to the filesystem (default: 20000 tokens, ~80KB)
Options for creating filesystem middleware.