@@ -26,6 +26,7 @@ members = [
     "crates/buzz-pair-relay",
     "crates/buzz-relay-mesh",
     "crates/buzz-dev-mcp",
+    "crates/buzz-voice",
     "examples/countdown-bot",
 ]
 exclude = ["desktop/src-tauri"]
 
@@ -276,6 +276,7 @@ test-unit:
     #!/usr/bin/env bash
     if command -v cargo-nextest &>/dev/null; then
         cargo nextest run -p buzz-core -p buzz-auth --lib
+        cargo nextest run -p buzz-voice --lib
         cargo nextest run -p buzz-cli
         # buzz-db migrator/lint tests: pure SQL-parsing unit tests (no infra).
         # They guard the embedded-migrator invariant (exactly the consolidated
 
@@ -0,0 +1,18 @@
+[package]
+name = "buzz-voice"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+description = "Reusable local voice primitives for Buzz"
+
+[dependencies]
+ort = { version = "=2.0.0-rc.12", default-features = false, features = ["api-24", "ndarray", "std"] }
+ort-sys = { version = "=2.0.0-rc.12", features = ["disable-linking"] }
+rand = "0.10"
+sentencepiece-model = "0.1"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+sherpa-onnx = "1.12"
+tokenizers = { version = "0.22", default-features = false, features = ["fancy-regex"] }
@@ -0,0 +1,22 @@
+//! Reusable local voice primitives for Buzz.
+
+pub mod pocket;
+
+pub use pocket::{
+    april_model_info, load_text_to_speech, load_voice_style, PocketModelInfo, PocketTts,
+    VoiceStyle, DEFAULT_VOICE, SAMPLE_RATE, VOICE_FILE_EXT,
+};
+
+/// One immutable artifact required by the April Pocket bundle.
+///
+/// `filename` is the bundle-relative file name, `sha256` pins its contents,
+/// `size_bytes` supports download progress and validation, and `quantized`
+/// identifies the INT8 components.
+pub type PocketModelArtifact = pocket::PocketModelArtifact;
+
+/// Language bundle selected from the pinned export.
+pub const APRIL_BUNDLE_ID: &str = pocket::APRIL_BUNDLE_ID;
+/// Pinned upstream export repository.
+pub const APRIL_MODEL_ID: &str = pocket::APRIL_MODEL_ID;
+/// Pinned revision containing the April bundle.
+pub const APRIL_MODEL_REVISION: &str = pocket::APRIL_MODEL_REVISION;
@@ -0,0 +1,167 @@
+//! April 2026 Pocket TTS engine for Buzz Desktop.
+//!
+//! The `english_2026-04` bundle uses SentencePiece tokenization, a learned
+//! voice BOS embedding, recurrent FlowLM state, and stateful Mimi decoding.
+//! Buzz selects the upstream three-graph INT8 variant while retaining the
+//! full-precision Mimi encoder and text conditioner specified by that variant.
+//!
+//! ## Attribution
+//!
+//! - Pocket TTS and Mimi: Kyutai, CC-BY-4.0.
+//! - ONNX export: KevinAHM/pocket-tts-onnx, CC-BY-4.0.
+//! - Reference voice: Kyutai's Mary preset (VCTK p333), CC-BY-4.0.
+//!
+//! `huddle::models` writes the complete attribution beside the cached bytes.
+
+use std::path::{Path, PathBuf};
+use std::sync::Mutex;
+
+use sherpa_onnx::Wave;
+
+#[path = "pocket_april.rs"]
+mod pocket_april;
+#[path = "pocket_models.rs"]
+mod pocket_models;
+
+use pocket_april::{prepare_april_prompt, AprilPocketTts};
+pub use pocket_models::{
+    april_model_info, PocketModelArtifact, PocketModelInfo, APRIL_BUNDLE_ID, APRIL_MODEL_ID,
+    APRIL_MODEL_REVISION,
+};
+
+/// Pocket TTS emits 24 kHz mono PCM.
+pub const SAMPLE_RATE: u32 = 24_000;
+
+/// Bundled reference voice name without its extension.
+pub const DEFAULT_VOICE: &str = "reference_sample";
+
+/// Pocket voice files are reference WAVs.
+pub const VOICE_FILE_EXT: &str = "wav";
+
+const TTS_NUM_THREADS: usize = 1;
+
+/// Loaded reference voice samples and their original sample rate.
+#[derive(Debug, Clone)]
+pub struct VoiceStyle {
+    samples: Vec<f32>,
+    sample_rate: i32,
+}
+
+/// Load a Pocket reference voice WAV from disk.
+pub fn load_voice_style(path: &Path) -> Result<VoiceStyle, String> {
+    let path_str = path
+        .to_str()
+        .ok_or_else(|| format!("voice path is not valid UTF-8: {}", path.display()))?;
+    let wave = Wave::read(path_str)
+        .ok_or_else(|| format!("could not read voice WAV at {}", path.display()))?;
+    let samples = wave.samples().to_vec();
+    if samples.is_empty() {
+        return Err(format!("voice WAV is empty: {}", path.display()));
+    }
+    Ok(VoiceStyle {
+        samples,
+        sample_rate: wave.sample_rate(),
+    })
+}
+
+/// Resident April INT8 Pocket TTS engine.
+pub struct PocketTts {
+    inner: Mutex<AprilPocketTts>,
+}
+
+/// Load Buzz Desktop's pinned April INT8 model.
+pub fn load_text_to_speech(model_dir: &str) -> Result<PocketTts, String> {
+    let dir = PathBuf::from(model_dir);
+    for artifact in april_model_info().artifacts {
+        let path = dir.join(artifact.filename);
+        if !path.is_file() {
+            return Err(format!(
+                "incomplete Pocket TTS {} INT8 bundle: missing {}",
+                APRIL_BUNDLE_ID,
+                path.display()
+            ));
+        }
+    }
+    Ok(PocketTts {
+        inner: Mutex::new(AprilPocketTts::load(&dir, TTS_NUM_THREADS)?),
+    })
+}
+
+impl PocketTts {
+    /// Split text into synthesis units that satisfy the bundle's exact
+    /// 50-token input limit.
+    pub fn split_text_into_chunks(&self, text: &str) -> Result<Vec<String>, String> {
+        let Some(prepared) = prepare_april_prompt(text) else {
+            return Ok(Vec::new());
+        };
+        self.inner
+            .lock()
+            .map_err(|_| "Pocket TTS engine lock poisoned".to_string())?
+            .split_prompt(&prepared)
+    }
+
+    /// Synthesize text with the supplied reference voice.
+    ///
+    /// Pocket detects language from text and this model uses one synthesis
+    /// step, so `_lang` and `_steps` intentionally do not affect output.
+    pub fn synth_chunk(
+        &self,
+        text: &str,
+        _lang: &str,
+        style: &VoiceStyle,
+        _steps: usize,
+    ) -> Result<Vec<f32>, String> {
+        let Some(prepared) = prepare_april_prompt(text) else {
+            return Ok(Vec::new());
+        };
+        let mut engine = self
+            .inner
+            .lock()
+            .map_err(|_| "Pocket TTS engine lock poisoned".to_string())?;
+        let chunks = engine.split_prompt(&prepared)?;
+        let mut samples = Vec::new();
+        for chunk in chunks {
+            let prepared = prepare_april_prompt(&chunk)
+                .ok_or_else(|| "Pocket TTS prompt chunk became empty".to_string())?;
+            samples.extend(engine.synth_chunk(&prepared, style)?);
+        }
+        Ok(samples)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn desktop_model_is_april_int8_only() {
+        let info = april_model_info();
+        assert_eq!(info.max_token_per_chunk, 50);
+        assert_eq!(info.sample_rate, SAMPLE_RATE);
+        assert!(info
+            .artifacts
+            .iter()
+            .any(|artifact| artifact.filename == "flow_lm_main_int8.onnx"));
+        assert!(!info
+            .artifacts
+            .iter()
+            .any(|artifact| artifact.filename == "flow_lm_main.onnx"));
+    }
+
+    #[test]
+    #[ignore = "requires BUZZ_POCKET_TEST_MODEL_DIR"]
+    fn production_api_emits_non_silent_april_int8_pcm() {
+        let dir = std::env::var("BUZZ_POCKET_TEST_MODEL_DIR")
+            .expect("set BUZZ_POCKET_TEST_MODEL_DIR to an April INT8 model directory");
+        let engine = load_text_to_speech(&dir).expect("load April INT8 engine");
+        let style = load_voice_style(&Path::new(&dir).join("reference_sample.wav"))
+            .expect("load reference voice");
+        let samples = engine
+            .synth_chunk("Bright birds begin beside the bay.", "en", &style, 1)
+            .expect("synthesize through the production API");
+
+        assert!(!samples.is_empty());
+        assert!(samples.iter().all(|sample| sample.is_finite()));
+        assert!(samples.iter().any(|sample| sample.abs() > 1.0e-6));
+    }
+}
@@ -24,12 +24,19 @@ pub struct PocketModelArtifact {
 /// Capabilities of Buzz Desktop's sole Pocket model.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct PocketModelInfo {
+    /// Language bundle selected from the pinned export.
     pub bundle_id: &'static str,
+    /// Upstream model repository.
     pub source_model_id: &'static str,
+    /// Pinned upstream model revision.
     pub revision: &'static str,
+    /// PCM output sample rate.
     pub sample_rate: u32,
+    /// Maximum input size declared by the bundle.
     pub max_token_per_chunk: usize,
+    /// Immutable files required by the runtime.
     pub artifacts: &'static [PocketModelArtifact],
+    /// Components quantized in the selected bundle.
     pub quantized_components: &'static [&'static str],
 }
 
 
@@ -49,6 +49,7 @@ export default defineConfig({
         "**/activity-scope-label-screenshots.spec.ts",
         "**/welcome-agent-modal-screenshots.spec.ts",
         "**/local-archive-screenshots.spec.ts",
+        "**/voice-settings.spec.ts",
         "**/agent-readiness-screenshots.spec.ts",
         "**/agent-error-state-screenshots.spec.ts",
         "**/edit-agent.spec.ts",
Original file line number	Diff line number	Diff line change
`@@ -26,6 +26,7 @@ members = [`
`26`	`26`	`"crates/buzz-pair-relay",`
`27`	`27`	`"crates/buzz-relay-mesh",`
`28`	`28`	`"crates/buzz-dev-mcp",`
	`29`	`+ "crates/buzz-voice",`
`29`	`30`	`"examples/countdown-bot",`
`30`	`31`	`]`
`31`	`32`	`exclude = ["desktop/src-tauri"]`