Module brain 

Brain (oxibrain) memory backend.

BrainMemoryBackend is the only durable-memory authority under the Oxi Foundation v1 host. The legacy local memory backends (memory_sqlite, memory_summary, memory_mnemopi, memory_workers, mnemopi) stay compilable during the migration window but are no longer durable: they are read-only mirrors, never write targets.

Wire protocol

oxibrain exposes its memory.* tool surface over a Unix-domain socket via the JSON-RPC client in oxibrain-client. The backend translates every MemoryBackend method into one oxibrain tool call:

MemoryBackend method	oxibrain tool	args shape
put	memory.put	{"content": ..., "kind": ..., "subject": ...}
search	memory.search	{"query": ..., "k": N}
list	memory.list	{"subject": ...}
delete	memory.delete	{"id": ...}

Degraded mode

When the daemon is unreachable, every mutation returns ToolError(String) carrying "backend unavailable: oxibrain daemon unreachable". The local file store is never consulted as a fallback, because doing so would silently duplicate memory across two authorities and break the Foundation contract. Tools surface degraded to the user instead of pretending the store succeeded.

Unix-only

oxibrain-client uses Unix-domain sockets. On non-Unix targets this module compiles to a stub that returns BackendUnavailable for every call. The same memory_info constant is used in both targets so the TUI’s health banner reads “degraded” identically.

Structs

BrainMemoryBackend

Brain memory backend. The Arc<Mutex<Option<…>>> wrapper yields interior mutability on the optional client while keeping the MemoryBackend trait object signature (Arc<…>, no &mut).

Enums

BrainHealth

Health of the Brain connection. Surfaced via memory_info so the TUI health banner reports the state without leaking the underlying transport.

MigrationError

Migration-specific error type. Distinguishes the cases the migration core cares about: backend offline, write failure, runtime failure.

Constants

DEFAULT_BRAIN_SCOPE

Default scope identifier passed to oxibrain when one is not provided. oxicode uses the project working directory when known; the fallback is the literal "default" so the daemon can route to a project bucket.

Functions

default_socket_path

Resolves the default socket path for the oxibrain daemon. Honors OXIBRAIN_SOCKET if set; otherwise $XDG_RUNTIME_DIR/oxibrain.sock (Linux) or ~/.oxi/run/oxibrain.sock (macOS).