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Filesystem Settings

Configure the sandbox filesystem: working directory, copy-on-write isolation, file size limits, and exclusion patterns.

Configuration

[workspace.filesystem]
workdir = "/workspace"
cow_isolation = false
persist_changes = true
max_file_size_bytes = 10485760
readonly_paths = ["/etc", "/usr"]
writable_paths = ["/workspace", "/tmp"]
exclude_patterns = ["**/node_modules/**", "**/target/**", "**/.git/**"]

Fields

Field Type Default Description
workdir string "/workspace" Agent working directory
cow_isolation boolean false Enable copy-on-write isolation
persist_changes boolean false Persist filesystem changes across restarts
max_file_size_bytes integer Maximum file size the agent can create
tmp_size_mb integer Temp directory size limit
readonly_paths string[] [] Paths mounted read-only
writable_paths string[] [] Explicitly writable paths (with CoW)
exclude_patterns string[] [] Glob patterns to exclude from agent access

Copy-on-Write Isolation

When cow_isolation = true, the sandbox filesystem operates with copy-on-write semantics (inspired by AgentFS). The agent can modify files freely, but changes are isolated from the source. This is useful for:

  • Safe experimentation — Changes don't affect the original codebase
  • Reproducible runs — Each launch starts from a clean state
  • Audit trail — All file operations are tracked