Files
VoiceAgent/apple_llm.py
T

237 lines
8.5 KiB
Python

"""A Pipecat processor that puts the native macOS / Apple Silicon LLM model in the LLM slot.
Supports:
1. Apple Intelligence / FoundationModels (via swift/llm-helper)
2. MLX local on-device LLM on Apple Silicon (via mlx-lm)
Streams response text frames (LLMFullResponseStartFrame, LLMTextFrame,
LLMFullResponseEndFrame) so text-to-speech downstream responds with low latency.
"""
import asyncio
import json
import os
import shutil
import subprocess
from pathlib import Path
from loguru import logger
from pipecat.frames.frames import (
CancelFrame,
EndFrame,
Frame,
InterruptionFrame,
LLMContextFrame,
LLMFullResponseEndFrame,
LLMFullResponseStartFrame,
LLMTextFrame,
StartFrame,
)
from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
_NOISE_TRANSCRIPTS = {
"",
".",
"thank you.",
"thanks for watching!",
"you",
"bye.",
"okay.",
"[blank_audio]",
"[silence]",
}
HERE = Path(__file__).parent
LLM_HELPER_PATH = HERE / "swift" / "llm-helper"
def probe_apple_llm() -> tuple[bool, str]:
"""Check if native macOS / Apple Silicon LLM options are available."""
if LLM_HELPER_PATH.exists() and os.access(LLM_HELPER_PATH, os.X_OK):
try:
res = subprocess.run(
[str(LLM_HELPER_PATH), "--check"],
capture_output=True,
text=True,
timeout=5.0,
)
if res.returncode == 0:
try:
payload = json.loads(res.stdout.strip())
if payload.get("available"):
return True, payload.get("reason", "macOS FoundationModels available")
except json.JSONDecodeError:
pass
except Exception:
pass
try:
import mlx_lm
return True, "Apple Silicon MLX local LLM engine available"
except ImportError:
return False, "Neither swift/llm-helper nor mlx-lm is available"
def _latest_user_text(context) -> str:
if not context or not hasattr(context, "messages"):
return ""
for msg in reversed(context.messages):
if isinstance(msg, dict) and msg.get("role") == "user":
content = msg.get("content", "")
if isinstance(content, str):
return content
elif isinstance(content, list):
text_parts = [c.get("text", "") for c in content if isinstance(c, dict)]
return " ".join(text_parts)
return ""
class MacOSLLM(FrameProcessor):
"""Runs user turns through macOS native LLM (Apple Intelligence or MLX)."""
def __init__(
self,
*,
model: str = "mlx-community/gemma-2-2b-it-4bit",
system_prompt: str | None = None,
observer=None,
**kwargs,
):
super().__init__(**kwargs)
self._model_name = model
self._system_prompt = system_prompt or "You are a helpful voice assistant. Keep answers brief and spoken naturally."
self._on_reply = observer
self._turn_task: asyncio.Task | None = None
self._history: list[dict[str, str]] = []
self._mlx_model = None
self._mlx_tokenizer = None
self._use_swift = False
async def process_frame(self, frame: Frame, direction: FrameDirection):
await super().process_frame(frame, direction)
if isinstance(frame, StartFrame):
await self.push_frame(frame, direction)
await self._connect()
elif isinstance(frame, (EndFrame, CancelFrame)):
await self._cancel_turn()
await self.push_frame(frame, direction)
elif isinstance(frame, InterruptionFrame):
await self._cancel_turn()
await self.push_frame(frame, direction)
elif isinstance(frame, LLMContextFrame):
text = _latest_user_text(frame.context)
await self._maybe_start_turn(text)
else:
await self.push_frame(frame, direction)
async def _connect(self):
available, reason = probe_apple_llm()
logger.info(f"macOS LLM engine: {reason}")
if LLM_HELPER_PATH.exists() and "FoundationModels available" in reason:
self._use_swift = True
logger.info("Using Swift FoundationModels engine.")
else:
self._use_swift = False
logger.info(f"Loading MLX model {self._model_name} on Apple Silicon...")
loop = asyncio.get_running_loop()
def _load():
from mlx_lm import load
return load(self._model_name)
self._mlx_model, self._mlx_tokenizer = await loop.run_in_executor(None, _load)
logger.info("MLX model loaded.")
async def _maybe_start_turn(self, text: str):
utterance = text.strip()
if utterance.lower() in _NOISE_TRANSCRIPTS or len(utterance) < 2:
logger.debug(f"Ignoring noise transcript: {utterance!r}")
return
await self._cancel_turn()
logger.info(f"You: {utterance}")
self._turn_task = self.create_task(self._run_turn(utterance))
async def _cancel_turn(self):
if not self._turn_task:
return
task, self._turn_task = self._turn_task, None
await self.cancel_task(task)
async def _run_turn(self, utterance: str):
self._history.append({"role": "user", "content": utterance})
await self.push_frame(LLMFullResponseStartFrame())
chunks: list[str] = []
try:
if self._use_swift:
proc = await asyncio.create_subprocess_exec(
str(LLM_HELPER_PATH),
"--prompt", utterance,
"--system", self._system_prompt,
"--stream",
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
)
while True:
line = await proc.stdout.readline()
if not line:
break
try:
data = json.loads(line.decode().strip())
if "delta" in data:
chunk = data["delta"]
chunks.append(chunk)
await self.push_frame(LLMTextFrame(chunk))
elif "text" in data and not chunks:
chunk = data["text"]
chunks.append(chunk)
await self.push_frame(LLMTextFrame(chunk))
except json.JSONDecodeError:
pass
await proc.wait()
else:
loop = asyncio.get_running_loop()
def _gen():
from mlx_lm import generate
from mlx_lm.sample_utils import make_sampler
# Keep history concise to avoid context drift and repetition
recent_history = self._history[-8:]
messages = [{"role": "system", "content": self._system_prompt}] + recent_history
prompt = self._mlx_tokenizer.apply_chat_template(
messages, add_generation_prompt=True, tokenize=False
)
sampler = make_sampler(temp=0.7)
return generate(
self._mlx_model,
self._mlx_tokenizer,
prompt=prompt,
max_tokens=150,
sampler=sampler,
verbose=False,
)
response_text = await loop.run_in_executor(None, _gen)
# Clean up any potential repetitive sentence tails
cleaned_text = response_text.strip()
chunks.append(cleaned_text)
await self.push_frame(LLMTextFrame(cleaned_text))
except asyncio.CancelledError:
logger.info("Turn cancelled mid-response.")
raise
except Exception as e:
logger.error(f"macOS LLM error: {e}")
err_msg = "Sorry, I ran into an error generating a response."
chunks.append(err_msg)
await self.push_frame(LLMTextFrame(err_msg))
finally:
await self.push_frame(LLMFullResponseEndFrame())
full_reply = "".join(chunks).strip()
if full_reply:
self._history.append({"role": "assistant", "content": full_reply})
logger.info(f"macOS LLM: {full_reply}")
if self._on_reply:
self._on_reply(full_reply)