feat: Add support for private endpoint in Azure STT

changelog/3764.added.md

@@ -0,0 +1 @@
+- Added support for specifying private endpoints for Azure Speech-to-Text, enabling use in private networks behind firewalls.

src/pipecat/services/azure/stt.py

@@ -63,6 +63,7 @@ class AzureSTTService(STTService):
         region: str,
         language: Language = Language.EN_US,
         sample_rate: Optional[int] = None,
+        private_endpoint: Optional[str] = None,
         endpoint_id: Optional[str] = None,
         ttfs_p99_latency: Optional[float] = AZURE_TTFS_P99,
         **kwargs,
@@ -74,6 +75,8 @@ class AzureSTTService(STTService):
             region: Azure region for the Speech service (e.g., 'eastus').
             language: Language for speech recognition. Defaults to English (US).
             sample_rate: Audio sample rate in Hz. If None, uses service default.
+            private_endpoint: Private endpoint for STT behind firewall.
+                See https://docs.azure.cn/en-us/ai-services/speech-service/speech-services-private-link?tabs=portal
             endpoint_id: Custom model endpoint id.
             ttfs_p99_latency: P99 latency from speech end to final transcript in seconds.
                 Override for your deployment. See https://github.com/pipecat-ai/stt-benchmark
@@ -85,6 +88,7 @@ class AzureSTTService(STTService):
             subscription=api_key,
             region=region,
             speech_recognition_language=language_to_azure_language(language),
+            endpoint=private_endpoint,
         )
 
         if endpoint_id: