diff --git a/src-tauri/src/transcription/crispasr.rs b/src-tauri/src/transcription/crispasr.rs
index 01068ad..3ddb46d 100644
--- a/src-tauri/src/transcription/crispasr.rs
+++ b/src-tauri/src/transcription/crispasr.rs
@@ -1,4 +1,5 @@
 use std::path::PathBuf;
+use std::process::Command;
 
 use serde::{Deserialize, Serialize};
 
@@ -34,16 +35,46 @@ impl Transcriber for CrispAsrTranscriber {
             return Err(AppError::ModelNotInstalled(input.options.model_id));
         };
 
-        if self.config.sidecar_name.is_none() {
+        if !model_path.exists() {
+            return Err(AppError::InvalidModel(format!(
+                "modelo não encontrado em {}",
+                model_path.display()
+            )));
+        }
+
+        let Some(sidecar_name) = &self.config.sidecar_name else {
             return Err(AppError::SidecarNotConfigured);
+        };
+
+        let threads = default_thread_count().to_string();
+        let output = Command::new(sidecar_name)
+            .arg("-m")
+            .arg(model_path)
+            .arg("-f")
+            .arg(&input.audio_path)
+            .arg("-t")
+            .arg(&threads)
+            .output()
+            .map_err(|error| AppError::Transcription(error.to_string()))?;
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr).trim().to_string();
+            return Err(AppError::Transcription(if stderr.is_empty() {
+                format!("sidecar encerrou com status {}", output.status)
+            } else {
+                stderr
+            }));
+        }
+
+        let text = String::from_utf8_lossy(&output.stdout).trim().to_string();
+        if text.is_empty() {
+            return Err(AppError::Transcription(
+                "sidecar não retornou texto transcrito".to_string(),
+            ));
         }
 
         Ok(TranscriptionResult {
-            text: format!(
-                "Transcrição local pendente via CrispASR para {} usando {}.",
-                input.audio_path.display(),
-                model_path.display()
-            ),
+            text,
             backend: "crispasr".to_string(),
             model_id: input.options.model_id,
             detected_language: input.options.language,
@@ -51,6 +82,13 @@ impl Transcriber for CrispAsrTranscriber {
     }
 }
 
+fn default_thread_count() -> usize {
+    std::thread::available_parallelism()
+        .map(|count| count.get())
+        .unwrap_or(2)
+        .clamp(1, 4)
+}
+
 #[cfg(test)]
 mod tests {
     use std::path::PathBuf;
@@ -75,6 +113,9 @@ mod tests {
             })
             .expect_err("modelo ausente deve falhar");
 
-        assert_eq!(err, AppError::ModelNotInstalled(DEFAULT_MODEL_ID.to_string()));
+        assert_eq!(
+            err,
+            AppError::ModelNotInstalled(DEFAULT_MODEL_ID.to_string())
+        );
     }
 }
diff --git a/src-tauri/src/ui_commands.rs b/src-tauri/src/ui_commands.rs
index 54aa8cf..7b08e87 100644
--- a/src-tauri/src/ui_commands.rs
+++ b/src-tauri/src/ui_commands.rs
@@ -46,7 +46,7 @@ pub(crate) fn stop_recording_and_transcribe(
         .clone();
 
     let transcriber = CrispAsrTranscriber::new(CrispAsrConfig {
-        sidecar_name: None,
+        sidecar_name: Some("parakeet-main".to_string()),
         model_path: Some(default_model_path(&state.model_dir)),
     });