fix(assemblyai): stop forcing continuous_partials=true for U3-Pro models

livekit-plugins/livekit-plugins-assemblyai/livekit/plugins/assemblyai/stt.py

@@ -148,14 +148,13 @@ def __init__(
             min_turn_silence: Minimum silence in ms before a confident end-of-turn is finalized.
             min_end_of_turn_silence_when_confident: Deprecated. Use min_turn_silence instead.
             continuous_partials: Whether to emit additional partial transcripts during long
-                turns at a steady ~3 second cadence. By default, partials are emitted at
-                two points: one at 750 ms after turn start (configurable via
-                `interruption_delay`), and one each time silence exceeds
-                `min_turn_silence` without ending the turn. When enabled (default in
-                LiveKit; AssemblyAI server defaults to False), additional partials covering
-                the full turn transcript are emitted approximately every 3 seconds while
-                speech continues, on top of those baseline partials. Only supported with
-                the Universal-3 Pro family models.
+                turns at a steady ~3 second cadence, on top of the baseline partials
+                (one at 750 ms after turn start, configurable via `interruption_delay`,
+                and one each time silence exceeds `min_turn_silence` without ending the
+                turn). Leave unset to use AssemblyAI's server defaults: enabled, except
+                when `speaker_labels` is on, where the server disables it so turns break
+                cleanly at speaker changes. Only supported with the Universal-3 Pro
+                family models.
             interruption_delay: How soon the first early partial is emitted, in ms.
                 Range 0–1000, default 500. Lower values produce faster time-to-first-token
                 for barge-in; higher values produce more confident first partials. Only
@@ -239,12 +238,6 @@ def __init__(
                         f"{', '.join(_U3_PRO_MODELS)} models."
                     )
 
-        # LiveKit defaults continuous_partials to True (vs. AssemblyAI's server default of
-        # False) for steady-cadence partials. This parameter is only supported for
-        # the Universal-3 Pro family, enforced by the validation above.
-        if not is_given(continuous_partials) and model in _U3_PRO_MODELS:
-            continuous_partials = True
-
         self._base_url = base_url
         assemblyai_api_key = api_key if is_given(api_key) else os.environ.get("ASSEMBLYAI_API_KEY")
         if not assemblyai_api_key:

tests/test_plugin_assemblyai_stt.py

@@ -192,12 +192,8 @@ async def test_start_time_has_default_before_plugin_override():
 
 
 async def test_continuous_partials_default():
-    """Test continuous_partials is not set by default for a non-u3-rt-pro-family model.
-
-    (The plugin default model is universal-3-5-pro, a u3-rt-pro-family model that
-    defaults continuous_partials to True — covered by
-    test_universal_3_5_pro_defaults_continuous_partials_true.)
-    """
+    """Test continuous_partials is not set by default so AssemblyAI's server defaults
+    apply (enabled, except when speaker_labels is on)."""
     from livekit.plugins.assemblyai import STT
 
     stt = STT(api_key="test-key", model="universal-streaming-english")
@@ -252,30 +248,29 @@ async def test_continuous_partials_update():
     assert stt._opts.continuous_partials is True
 
 
-async def test_continuous_partials_defaults_to_true_for_u3_rt_pro():
-    """Test continuous_partials defaults to True when model is u3-rt-pro (LiveKit-only
-    default; AssemblyAI server defaults to False)."""
+async def test_continuous_partials_unset_by_default_for_u3_rt_pro():
+    """continuous_partials is left unset for u3-rt-pro so AssemblyAI's server defaults
+    apply (enabled, but disabled by the server when speaker_labels is on)."""
     from livekit.plugins.assemblyai import STT
 
     stt = STT(api_key="test-key", model="u3-rt-pro")
-    assert stt._opts.continuous_partials is True
+    assert stt._opts.continuous_partials is NOT_GIVEN
 
 
-async def test_continuous_partials_explicit_false_overrides_livekit_default():
-    """Test explicit continuous_partials=False overrides the LiveKit-only True default."""
+async def test_continuous_partials_explicit_false():
+    """Test explicit continuous_partials=False is preserved."""
     from livekit.plugins.assemblyai import STT
 
     stt = STT(api_key="test-key", model="u3-rt-pro", continuous_partials=False)
     assert stt._opts.continuous_partials is False
 
 
 async def test_continuous_partials_update_from_default():
-    """Test continuous_partials can be updated via update_options away from LiveKit default."""
+    """Test continuous_partials can be set via update_options when unset at construction."""
     from livekit.plugins.assemblyai import STT
 
-    # LiveKit defaults this to True for u3-rt-pro
     stt = STT(api_key="test-key", model="u3-rt-pro")
-    assert stt._opts.continuous_partials is True
+    assert stt._opts.continuous_partials is NOT_GIVEN
 
     stt.update_options(continuous_partials=False)
     assert stt._opts.continuous_partials is False
@@ -412,7 +407,7 @@ def _fake_create_task(coro, *args, **kwargs):
 #
 # u3-rt-pro-beta-1 shares all u3-rt-pro behavior, so the u3-pro-gated params
 # (prompt, agent_context, previous_context_n_turns, continuous_partials,
-# interruption_delay) are accepted with it, and continuous_partials defaults to True.
+# interruption_delay) are accepted with it.
 # ---------------------------------------------------------------------------
 
 
@@ -422,8 +417,8 @@ async def test_u3_rt_pro_beta_1_accepted():
 
     stt = STT(api_key="test-key", model="u3-rt-pro-beta-1")
     assert stt._opts.speech_model == "u3-rt-pro-beta-1"
-    # continuous_partials defaults to True for the u3-rt-pro family
-    assert stt._opts.continuous_partials is True
+    # continuous_partials is left unset so AssemblyAI's server defaults apply
+    assert stt._opts.continuous_partials is NOT_GIVEN
 
 
 async def test_u3_rt_pro_beta_1_accepts_u3_pro_params():
@@ -557,12 +552,13 @@ async def test_universal_3_5_pro_accepts_u3_pro_params():
     assert stt._opts.interruption_delay == 300
 
 
-async def test_universal_3_5_pro_defaults_continuous_partials_true():
-    """continuous_partials defaults to True for universal-3-5-pro (u3-rt-pro family)."""
+async def test_universal_3_5_pro_leaves_continuous_partials_unset():
+    """continuous_partials is left unset for universal-3-5-pro so AssemblyAI's server
+    defaults apply (enabled, but disabled by the server when speaker_labels is on)."""
     from livekit.plugins.assemblyai import STT
 
     stt = STT(api_key="test-key", model="universal-3-5-pro")
-    assert stt._opts.continuous_partials is True
+    assert stt._opts.continuous_partials is NOT_GIVEN
 
 
 # ---------------------------------------------------------------------------
@@ -717,13 +713,14 @@ async def test_voice_focus_allowed_for_all_u3_pro_family_models():
         assert stt._opts.voice_focus == "far-field"
 
 
-async def test_default_model_defaults_continuous_partials_true():
-    """A bare STT() (relying on the default model) defaults continuous_partials to True,
-    tying the default-model choice to its u3-rt-pro-family behavior."""
+async def test_default_model_leaves_continuous_partials_unset():
+    """A bare STT() (relying on the default model) leaves continuous_partials unset so
+    AssemblyAI's server defaults apply (enabled, but disabled by the server when
+    speaker_labels is on)."""
     from livekit.plugins.assemblyai import STT
 
     stt = STT(api_key="test-key")
-    assert stt._opts.continuous_partials is True
+    assert stt._opts.continuous_partials is NOT_GIVEN
 
 
 # ---------------------------------------------------------------------------