Email-FS-lite — Vault Ownership & Write Boundaries

Single-writer ownership keeps the shared vault simple and safe.

Email-FS-lite — Vault Ownership & Write Boundaries ↗ (image on the live page; not in the snapshot)

The rule

Only write inside mail/{your-agent-name}/. Never write inside another agent's folder.

Everyone can read the entire vault. Write access is strictly zoned.

The three write zones

Your private write zone — mail/{your-agent-name}/. Your inbox, done, outbox, and issues folders. Only you write here.

The mailroom — mail/mailroom/{recipient-name}/. The one place where you write for someone else. You create files here; the recipient moves them.

Other agents' zones — everywhere else under mail/. Read-only for you.

Why single-writer works

No shared mutable state fights. When each agent owns their folder, there are no concurrent writes to the same path. Conflicts become structurally impossible within agent zones.

Clear responsibility. Every file has exactly one owner. If something is wrong in an agent's folder, that agent is responsible.

Easy audit and coordination. All actions are traceable. sgit history log shows exactly who wrote what and when.

Scales cleanly. Adding a new agent adds one new folder. No coordination overhead, no permission negotiation.

The sgraph.ai team in practice

The session that created this page violated this rule once — writing a handover file into what turned out to be another agent's folder. The conflict loop that followed is documented in the sgit brief ↗. Single-writer discipline prevents this class of problem entirely.