kokoro-speakd

Persistent Kokoro TTS daemon for Claude Code and other clients. Loads the model once and serves synthesis requests over a Unix domain socket, so a machine running 10+ concurrent Claude Code sessions doesn't pay the cold-start cost on every response.

• Single process, single model in RAM, regardless of how many clients.
• Preemption over queueing — new speech always cancels older in-flight playback, which is what you actually want when juggling many sessions.
• Lazy per-language pipelines — default English loads at startup, other languages spin up on first use.
• Nix-first packaging — flake.nix exports both the daemon and a stdlib-only client, with dlinfo/en_core_web_sm workarounds baked in so python3Packages.kokoro builds cleanly on darwin.
• Line-delimited JSON protocol over Unix sockets, trivial to drive from any shell or language.

Capability

Pattern. Persistent Kokoro TTS daemon over a Unix socket — one kokoro-speakd process holds the Kokoro-82M weights and en_core_web_sm phonemizer in RAM; a stdlib-only kokoro-speak client speaks line-delimited JSON to it.

Trade-off. A 5–8 s cold model load on first boot, in exchange for sub-500 ms warm-call latency on every subsequent kokoro-speak invocation. Per-call model reload is avoided entirely, regardless of how many concurrent clients are talking to the daemon.

Use when. A Claude Code hook, shell pipeline, or agent loop needs synchronous TTS without paying PyTorch warm-up cost per response — markdown stripping is built in, preemption replaces queueing so the latest thought always wins, and the socket path is stable enough to drop into Stop / SessionEnd / UserPromptSubmit hooks.

pip install kokoro-speakd                # PyPI (when first release cut)
kokoro-speakd &                          # daemon, single instance per user
echo "hello world" | kokoro-speak        # stdin → speech, ~412 ms warm-call
kokoro-speak < release-notes.md          # markdown → strip → speech
kokoro-speak interrupt                   # cancel in-flight playback

Demo

A non-interactive 18-second asciinema cast covering kokoro-speakd --help, daemon start with warm-load timing, kokoro-speak ping, an inline echo … | kokoro-speak, a markdown-stripping kokoro-speak < file.md, and kokoro-speak interrupt is checked into the repo at docs/assets/kokoro-demo.cast. Replay locally:

asciinema play docs/assets/kokoro-demo.cast

A hosted player embed will land in a follow-up PR after the cast is uploaded to asciinema.org.

How kokoro-speakd compares

Closest peers in the open-source TTS-client ecosystem:

For multi-tenant TTS gateways and self-hosted REST services see coqui-ai/TTS or openedai-speech — different shape of problem, listed in What this is NOT.

What this is NOT

• Not a multi-tenant TTS SaaS. Each kokoro-speakd install is scoped to one user, one model in RAM, one socket.
• Not a REST gateway. Use coqui-ai/TTS or openedai-speech if that's what you want.
• Not a real-time streaming TTS. Synthesis runs per-request; preemption swaps the playback target, it does not splice mid-utterance.
• Not a voice-cloning tool. Voices are picked from the 54 ONNX models Kokoro ships; bring-your-own-voice is upstream's problem.

Quick start (with Nix)

# Start the daemon in the foreground:
nix run github:yolo-labz/kokoro-speakd

# From another terminal:
echo "hello from kokoro" | nix run github:yolo-labz/kokoro-speakd#kokoro-speak
nix run github:yolo-labz/kokoro-speakd#kokoro-speak -- ping
nix run github:yolo-labz/kokoro-speakd#kokoro-speak -- interrupt

The first request after a cold daemon start takes ~5–8 seconds while the PyTorch weights warm up. Every request after that is <500 ms regardless of how many clients are talking to the daemon.

Claude Code hook integration (nix-darwin / home-manager)

1. Add the flake as an input:

   kokoro-speakd = {
     url = "github:yolo-labz/kokoro-speakd";
     inputs.nixpkgs.follows = "nixpkgs";
   };
   

2. Install the daemon and client on your user, and register a launchd agent so the daemon auto-starts at login:

   { inputs, pkgs, system, ... }: let
     kokoro = inputs.kokoro-speakd.packages.${system};
   in {
     home.packages = [ kokoro.kokoro-speak kokoro.kokoro-speakd ];
   
     launchd.agents.kokoro-speakd = {
       enable = true;
       config = {
         ProgramArguments = [ "${kokoro.kokoro-speakd}/bin/kokoro-speakd" ];
         KeepAlive = true;
         RunAtLoad = true;
         StandardOutPath = "${config.home.homeDirectory}/.cache/claude-code-tts/launchd.out.log";
         StandardErrorPath = "${config.home.homeDirectory}/.cache/claude-code-tts/launchd.err.log";
       };
     };
   }
   

3. Point Claude Code's Stop, UserPromptSubmit, and SessionEnd hooks at kokoro-speak — the daemon handles the rest. See phsb5321/NixOS for a full reference integration, including the transcript walk that pulls Claude's final narrative text out of the JSONL log.

Protocol

One JSON request per connection, newline-terminated. Response is a single newline-terminated JSON object.

// speak (replaces any in-flight speech)
{"action": "speak", "text": "hello there", "voice": "af_sky", "lang": "a"}
// -> {"status": "queued", "id": 42}
// -> {"status": "loading"}   // model still warming up
// -> {"status": "empty"}     // text was whitespace after stripping

// cancel current playback
{"action": "interrupt"}
// -> {"status": "ok"}

// health check
{"action": "ping"}
// -> {"status": "pong", "ready": true}

Defaults: voice="af_sky", lang="a" (American English). Override per request or globally via KOKORO_DEFAULT_VOICE / KOKORO_DEFAULT_LANG.

Environment

Daemon:

• KOKORO_SPEAKD_SOCKET — socket path (default ~/.cache/claude-code-tts/kokoro-speakd.sock)
• KOKORO_SPEAKD_LOG — log file path
• KOKORO_DEFAULT_VOICE, KOKORO_DEFAULT_LANG — fallback values

Client (kokoro-speak):

• KOKORO_VOICE, KOKORO_LANG — per-request overrides
• KOKORO_MAX — hard char cap on the text sent (default 5000)
• KOKORO_SPEAKD_SOCKET — matching override to reach a non-default daemon

Voices

Kokoro ships 54 voices. American English defaults to af_sky; see hexgrad's VOICES.md for the full list including British English, Japanese, Mandarin, French, Italian, and more. Set KOKORO_VOICE=af_bella (etc.) and reload the daemon.

License

MIT. See LICENSE.

Services

Compliance-grade AI architecture for regulated workloads — async-first, USD-denominated, LATAM-based / EN-fluent. See blog.home301server.com.br/services.