Module resident 

Resident engine: a per-user background process that keeps the loaded model in memory so consecutive ftts say invocations skip the multi-second model load.

Shape: ftts say connects to a loopback TCP daemon (spawned on demand from the same binary) and sends one synthesis request; the daemon holds the hydrated LoadedModel and TtsEngine between requests and exits by itself after a configurable idle period (default ten minutes). Everything else — argument handling, voice resolution, robot events, output writing — stays in the client process, so the observable contract of ftts say is unchanged.

Loopback TCP is the one transport that behaves identically on Linux, macOS, and Windows with only the standard library. Access control is the state file, not the port: the daemon binds an ephemeral 127.0.0.1 port and writes {port, token, …} to a file only the invoking user can read (0600 on Unix; the per-user profile directory’s ACL on Windows), and every request must present that token. Texts are sensitive, so the daemon holds no history: requests are served from memory and dropped.

Failure philosophy: the resident path may only ever make say faster, never break it. Every transport-level problem (no daemon, stale state file, version or artifact mismatch, malformed reply) falls back to the classic in-process load. Only a genuine synthesis error crosses the wire as an error, carrying its exit-code class.

Structs

WireRequest

One synthesis request as it crosses the wire. Everything the daemon needs to rebuild the exact SynthesisRequest the client would have run inline.

Functions

enabled

Whether the resident path is enabled at all: on by default, disabled by the say flag or by FTTS_NO_RESIDENT=1 for scripts that cannot pass flags.

run_daemon

Run the resident daemon until the idle period passes without a request.

try_synthesize

Try to synthesize through a resident daemon, spawning one if none is listening.