Unable to run PydanticAI

Hi, I have been trying for days to deploy the python code with pydanticai. Locally, everything works well, but on vercel, I am constantly getting FUNCTION_INVOCATION_FAILED error. when I check the log, I see the following:

1Traceback (most recent call last):2File "/var/task/vc__handler__python.py", line 14, in <module>3__vc_spec.loader.exec_module(__vc_module)4File "<frozen importlib._bootstrap_external>", line 995, in exec_module5File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed6File "/var/task/src/main_vercel.py", line 1, in <module>7from fastapi import FastAPI, Request, WebSocket8File "/var/task/fastapi/__init__.py", line 7, in <module>9from .applications import FastAPI as FastAPI10File "/var/task/fastapi/applications.py", line 16, in <module>11from fastapi import routing12File "/var/task/fastapi/routing.py", line 24, in <module>13from fastapi import params14File "/var/task/fastapi/params.py", line 5, in <module>15from fastapi.openapi.models import Example16File "/var/task/fastapi/openapi/models.py", line 4, in <module>17from fastapi._compat import (18File "/var/task/fastapi/_compat.py", line 21, in <module>19from fastapi.exceptions import RequestErrorModel20File "/var/task/fastapi/exceptions.py", line 3, in <module>21from pydantic import BaseModel, create_model22File "<frozen importlib._bootstrap>", line 1412, in _handle_fromlist23File "/var/task/pydantic/__init__.py", line 421, in __getattr__24module = import_module(module_name, package=package)25^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^26File "/var/lang/lib/python3.12/importlib/__init__.py", line 90, in import_module27return _bootstrap._gcd_import(name[level:], package, level)28^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^29File "/var/task/pydantic/main.py", line 34, in <module>30from ._internal import (31File "/var/task/pydantic/_internal/_model_construction.py", line 25, in <module>32from ._generate_schema import GenerateSchema33File "/var/task/pydantic/_internal/_generate_schema.py", line 42, in <module>34from uuid import UUID35File "/var/task/uuid.py", line 13836if not 0 <= time_low < 1<<32L:37^38SyntaxError: invalid decimal literal39Python process exited with exit status: 1. The logs above can help with debugging the issue.

the main_vercel.py script is the following:

1from fastapi import FastAPI, Request, WebSocket2from fastapi.middleware.cors import CORSMiddleware3from dotenv import load_dotenv4import os5from src.routers import (6    image_router, 7    auth_router, 8    financial_stats_router, 9    receipt, 10    financial_analytics_router, 11    store, 12    tags,13    spending_sheet,14    categories,15    user_settings_router16)17from src.websockets.websocket_manager import manager18from src.database.db_utils import init_db19from src.type_defs.dynamic_types import initialize_types20from contextlib import asynccontextmanager2122# Load environment variables23load_dotenv()2425# Define lifespan first26@asynccontextmanager27async def lifespan(app: FastAPI):28    """Lifespan context manager for FastAPI app"""29    # Startup30    await init_db()31    await initialize_types()32    yield33    # Shutdown34    # Add any cleanup code here3536# Create FastAPI app instance ONCE with lifespan37app = FastAPI(38    title="Expenzor API",39    description="Backend API for Expenzor expense tracking application",40    version="1.0.0",41    lifespan=lifespan42)4344# Configure CORS45origins = os.getenv("ALLOWED_ORIGINS", https://expenzor.com,https://www.expenzor.com").split(",")4647app.add_middleware(48    CORSMiddleware,49    allow_origins=origins,50    allow_credentials=True,51    allow_methods=["*"],  # Allows all methods52    allow_headers=["*"],  # Allows all headers53    expose_headers=["*"]  # Exposes all headers54)5556# Add request logging middleware for production57@app.middleware("http")58async def log_requests(request: Request, call_next):59    # Log basic request info60    print(f"61--- Request ---")62    print(f"Method: {request.method}")63    print(f"URL: {request.url}")64    65    # Skip body logging for multipart/form-data (file uploads)66    if not request.headers.get("content-type", "").startswith("multipart/form-data"):67        body = await request.body()68        try:69            print(f"Body: {body.decode()}")70        except UnicodeDecodeError:71            print("Body: <binary data>")72    else:73        print("Body: <file upload>")74    75    response = await call_next(request)76    print(f"Response status code: {response.status_code}")77    return response7879# WebSocket endpoint80@app.websocket("/ws/{client_id}")81async def websocket_endpoint(websocket: WebSocket, client_id: str):82    print(f"WebSocket connection attempt from client: {client_id}")83    await manager.connect(websocket, client_id)84    try:85        while True:86            data = await websocket.receive_text()87            print(f"Received message from client {client_id}: {data}")88    except Exception as e:89        print(f"WebSocket error for client {client_id}: {e}")90    finally:91        print(f"WebSocket connection closed for client {client_id}")92        await manager.disconnect(websocket, client_id)9394# Include routers95app.include_router(image_router)96app.include_router(auth_router)97app.include_router(financial_stats_router)98app.include_router(receipt.router)99app.include_router(financial_analytics_router)100app.include_router(store.router)101app.include_router(tags.router)102app.include_router(spending_sheet.router)103app.include_router(categories.router)104app.include_router(user_settings_router)105106# Root endpoint107@app.get("/")108async def root():109    return {"message": "Welcome to Expenzor API"}110111# Health check endpoint112@app.get("/health")113async def health_check():114    return {"status": "ok"}115116if __name__ == "__main__":117    import uvicorn118    import sys119    120    # Determine environment121    env = os.getenv("ENV", "development")122    123    # Configure server settings based on environment124    host = "0.0.0.0"125    port = int(os.getenv("PORT", "8000"))126    reload_enabled = env == "development"127    128    # Check if running in debug mode129    is_debug = sys.gettrace() is not None130    131    if is_debug:132        print("Debug mode detected. Use the 'FastAPI' launch configuration to debug with the server running.")133    else:134        print(f"Starting server in {env} mode")135        print(f"Host: {host}")136        print(f"Port: {port}")137        print(f"Auto-reload: {'enabled' if reload_enabled else 'disabled'}")138        139        if reload_enabled:140            # When reload is enabled, we need to use the import string141            uvicorn.run(142                "src.main:app",143                host=host,144                port=port,145                reload=True,146                log_level="info"147            )148        else:149            # When reload is disabled, we can use the app instance directly150            uvicorn.run(151                app,152                host=host,153                port=port,154                reload=False,155                log_level="info"156            )

these are essential imports in some other script:

1from dataclasses import dataclass2import asyncio3from pydantic import BaseModel, Field4from pydantic_ai import Agent, RunContext5from uuid import UUID, uuid4

this is the requirements.txt file:

1aiohappyeyeballs==2.4.42aiohttp==3.11.113aiosignal==1.3.24annotated-types==0.7.05anyio==4.8.06asyncpg==0.29.07attrs==25.1.08bcrypt==4.2.19boto3==1.29.010botocore==1.32.711cachetools==5.5.112certifi==2025.1.3113cffi==1.17.114charset-normalizer==3.4.115click==8.1.816colorama==0.4.617cryptography==44.0.018deprecation==2.1.019distro==1.9.020dnspython==2.7.021ecdsa==0.19.022email_validator==2.2.023eval_type_backport==0.2.224fastapi==0.115.025fastavro==1.10.026filelock==3.17.027frozenlist==1.5.028fsspec==2025.2.029google-auth==2.38.030greenlet==3.1.131griffe==1.5.632h11==0.14.033h2==4.2.034hpack==4.1.035httpcore==1.0.736httptools==0.6.437httpx==0.28.138httpx-sse==0.4.039huggingface-hub==0.28.140hyperframe==6.1.041idna==3.1042jiter==0.8.243jmespath==1.0.144jsonpath-python==1.0.645logfire-api==3.5.046multidict==6.1.047mypy-extensions==1.0.048ollama==0.4.749openai==1.61.050packaging==24.251passlib==1.7.452Pillow==10.1.053postgrest==0.19.354propcache==0.2.155pyasn1==0.6.156pyasn1_modules==0.4.157pycparser==2.2258pydantic-ai==0.0.2159pydantic_core==2.27.260python-dateutil==2.9.0.post061python-dotenv==1.0.062python-jose==3.3.063python-magic==0.4.2764python-multipart==0.0.665PyYAML==6.0.266realtime==2.3.067requests==2.32.368rsa==4.969s3transfer==0.7.070six==1.17.071sniffio==1.3.172SQLAlchemy==2.0.2373storage3==0.11.374StrEnum==0.4.1575supabase==2.12.076supafunc==0.9.377tokenizers==0.21.078tqdm==4.67.179types-requests==2.32.0.2024101680typing-inspect==0.9.081typing_extensions==4.12.282urllib3==2.0.783uvicorn==0.30.684uvloop==0.21.085watchfiles==1.0.486websockets==12.087yarl==1.18.3

I would be thankful if anyone helped me with solving the issue. I suspect there might be an issue with pydantic v2.x but I can't use older version due to other dependencies.

1"""2Patched UUID module for Python 3.12 compatibility.3This module provides a drop-in replacement for the standard uuid module.4"""5import os6import random7from typing import Optional, Union, Tuple89# Constants from the original UUID module10NAMESPACE_DNS = '6ba7b810-9dad-11d1-80b4-00c04fd430c8'11NAMESPACE_URL = '6ba7b811-9dad-11d1-80b4-00c04fd430c8'12NAMESPACE_OID = '6ba7b812-9dad-11d1-80b4-00c04fd430c8'13NAMESPACE_X500 = '6ba7b814-9dad-11d1-80b4-00c04fd430c8'1415class UUID:16 def __init__(self, hex: Optional[str] = None, bytes_: Optional[bytes] = None, 17 int_: Optional[int] = None, version: Optional[int] = None):18 if [hex, bytes_, int_].count(None) != 2:19 raise TypeError('Need exactly one of hex, bytes_, or int_')20 21 if hex is not None:22 hex = hex.replace('urn:', '').replace('uuid:', '')23 hex = hex.strip('{}').replace('-', '')24 if len(hex) != 32:25 raise ValueError('Invalid UUID string')26 self._int = int(hex, 16)27 elif bytes_ is not None:28 if len(bytes_) != 16:29 raise ValueError('Invalid UUID bytes')30 self._int = int.from_bytes(bytes_, byteorder='big')31 elif int_ is not None:32 self._int = int_33 34 if version is not None:35 if not 1 <= version <= 5:36 raise ValueError('Invalid version number')37 # Set version38 self._int &= ~(0xf000)39 self._int |= version << 1240 41 @property42 def bytes(self) -> bytes:43 return self._int.to_bytes(16, byteorder='big')44 45 @property46 def hex(self) -> str:47 return '%032x' % self._int48 49 @property50 def int(self) -> int:51 return self._int52 53 def __str__(self) -> str:54 hex = self.hex55 return f'{hex[:8]}-{hex[8:12]}-{hex[12:16]}-{hex[16:20]}-{hex[20:]}'56 57 def __repr__(self) -> str:58 return f'UUID({str(self)})'59 60 def __eq__(self, other: object) -> bool:61 if isinstance(other, UUID):62 return self._int == other._int63 return NotImplemented64 65 def __hash__(self) -> int:66 return hash(self._int)6768def uuid4() -> UUID:69 """Generate a random UUID (version 4)."""70 # Get 16 random bytes71 random_bytes = os.urandom(16)72 # Set version 4 and variant bits73 random_bytes = bytearray(random_bytes)74 random_bytes[6] = (random_bytes[6] & 0x0f) | 0x40 # version 475 random_bytes[8] = (random_bytes[8] & 0x3f) | 0x80 # variant76 return UUID(bytes_=bytes(random_bytes))7778# Expose the main functions and constants79__all__ = ['UUID', 'uuid4', 'NAMESPACE_DNS', 'NAMESPACE_URL', 'NAMESPACE_OID', 'NAMESPACE_X500']

1Traceback (most recent call last):2File "/var/task/vc__handler__python.py", line 14, in <module>3__vc_spec.loader.exec_module(__vc_module)4File "<frozen importlib._bootstrap_external>", line 995, in exec_module5File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed6File "/var/task/src/main_vercel.py", line 1, in <module>7from fastapi import FastAPI, Request, WebSocket8File "/var/task/fastapi/__init__.py", line 7, in <module>9from .applications import FastAPI as FastAPI10File "/var/task/fastapi/applications.py", line 16, in <module>11from fastapi import routing12File "/var/task/fastapi/routing.py", line 24, in <module>13from fastapi import params14File "/var/task/fastapi/params.py", line 5, in <module>15from fastapi.openapi.models import Example16File "/var/task/fastapi/openapi/models.py", line 4, in <module>17from fastapi._compat import (18File "/var/task/fastapi/_compat.py", line 21, in <module>19from fastapi.exceptions import RequestErrorModel20File "/var/task/fastapi/exceptions.py", line 3, in <module>21from pydantic import BaseModel, create_model22File "<frozen importlib._bootstrap>", line 1412, in _handle_fromlist23File "/var/task/pydantic/__init__.py", line 421, in __getattr__24module = import_module(module_name, package=package)25^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^26File "/var/lang/lib/python3.12/importlib/__init__.py", line 90, in import_module27return _bootstrap._gcd_import(name[level:], package, level)28^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^29File "/var/task/pydantic/main.py", line 34, in <module>30from ._internal import (31File "/var/task/pydantic/_internal/_model_construction.py", line 25, in <module>32from ._generate_schema import GenerateSchema33File "/var/task/pydantic/_internal/_generate_schema.py", line 42, in <module>34from uuid import UUID35File "/var/task/uuid.py", line 13836if not 0 <= time_low < 1<<32L:37^38SyntaxError: invalid decimal literal39Python process exited with exit status: 1. The logs above can help with debugging the issue.

the main_vercel.py script is the following:

1from fastapi import FastAPI, Request, WebSocket2from fastapi.middleware.cors import CORSMiddleware3from dotenv import load_dotenv4import os5from src.routers import (6    image_router, 7    auth_router, 8    financial_stats_router, 9    receipt, 10    financial_analytics_router, 11    store, 12    tags,13    spending_sheet,14    categories,15    user_settings_router16)17from src.websockets.websocket_manager import manager18from src.database.db_utils import init_db19from src.type_defs.dynamic_types import initialize_types20from contextlib import asynccontextmanager2122# Load environment variables23load_dotenv()2425# Define lifespan first26@asynccontextmanager27async def lifespan(app: FastAPI):28    """Lifespan context manager for FastAPI app"""29    # Startup30    await init_db()31    await initialize_types()32    yield33    # Shutdown34    # Add any cleanup code here3536# Create FastAPI app instance ONCE with lifespan37app = FastAPI(38    title="Expenzor API",39    description="Backend API for Expenzor expense tracking application",40    version="1.0.0",41    lifespan=lifespan42)4344# Configure CORS45origins = os.getenv("ALLOWED_ORIGINS", https://expenzor.com,https://www.expenzor.com").split(",")4647app.add_middleware(48    CORSMiddleware,49    allow_origins=origins,50    allow_credentials=True,51    allow_methods=["*"],  # Allows all methods52    allow_headers=["*"],  # Allows all headers53    expose_headers=["*"]  # Exposes all headers54)5556# Add request logging middleware for production57@app.middleware("http")58async def log_requests(request: Request, call_next):59    # Log basic request info60    print(f"61--- Request ---")62    print(f"Method: {request.method}")63    print(f"URL: {request.url}")64    65    # Skip body logging for multipart/form-data (file uploads)66    if not request.headers.get("content-type", "").startswith("multipart/form-data"):67        body = await request.body()68        try:69            print(f"Body: {body.decode()}")70        except UnicodeDecodeError:71            print("Body: <binary data>")72    else:73        print("Body: <file upload>")74    75    response = await call_next(request)76    print(f"Response status code: {response.status_code}")77    return response7879# WebSocket endpoint80@app.websocket("/ws/{client_id}")81async def websocket_endpoint(websocket: WebSocket, client_id: str):82    print(f"WebSocket connection attempt from client: {client_id}")83    await manager.connect(websocket, client_id)84    try:85        while True:86            data = await websocket.receive_text()87            print(f"Received message from client {client_id}: {data}")88    except Exception as e:89        print(f"WebSocket error for client {client_id}: {e}")90    finally:91        print(f"WebSocket connection closed for client {client_id}")92        await manager.disconnect(websocket, client_id)9394# Include routers95app.include_router(image_router)96app.include_router(auth_router)97app.include_router(financial_stats_router)98app.include_router(receipt.router)99app.include_router(financial_analytics_router)100app.include_router(store.router)101app.include_router(tags.router)102app.include_router(spending_sheet.router)103app.include_router(categories.router)104app.include_router(user_settings_router)105106# Root endpoint107@app.get("/")108async def root():109    return {"message": "Welcome to Expenzor API"}110111# Health check endpoint112@app.get("/health")113async def health_check():114    return {"status": "ok"}115116if __name__ == "__main__":117    import uvicorn118    import sys119    120    # Determine environment121    env = os.getenv("ENV", "development")122    123    # Configure server settings based on environment124    host = "0.0.0.0"125    port = int(os.getenv("PORT", "8000"))126    reload_enabled = env == "development"127    128    # Check if running in debug mode129    is_debug = sys.gettrace() is not None130    131    if is_debug:132        print("Debug mode detected. Use the 'FastAPI' launch configuration to debug with the server running.")133    else:134        print(f"Starting server in {env} mode")135        print(f"Host: {host}")136        print(f"Port: {port}")137        print(f"Auto-reload: {'enabled' if reload_enabled else 'disabled'}")138        139        if reload_enabled:140            # When reload is enabled, we need to use the import string141            uvicorn.run(142                "src.main:app",143                host=host,144                port=port,145                reload=True,146                log_level="info"147            )148        else:149            # When reload is disabled, we can use the app instance directly150            uvicorn.run(151                app,152                host=host,153                port=port,154                reload=False,155                log_level="info"156            )

these are essential imports in some other script:

1from dataclasses import dataclass2import asyncio3from pydantic import BaseModel, Field4from pydantic_ai import Agent, RunContext5from uuid import UUID, uuid4

this is the requirements.txt file:

1aiohappyeyeballs==2.4.42aiohttp==3.11.113aiosignal==1.3.24annotated-types==0.7.05anyio==4.8.06asyncpg==0.29.07attrs==25.1.08bcrypt==4.2.19boto3==1.29.010botocore==1.32.711cachetools==5.5.112certifi==2025.1.3113cffi==1.17.114charset-normalizer==3.4.115click==8.1.816colorama==0.4.617cryptography==44.0.018deprecation==2.1.019distro==1.9.020dnspython==2.7.021ecdsa==0.19.022email_validator==2.2.023eval_type_backport==0.2.224fastapi==0.115.025fastavro==1.10.026filelock==3.17.027frozenlist==1.5.028fsspec==2025.2.029google-auth==2.38.030greenlet==3.1.131griffe==1.5.632h11==0.14.033h2==4.2.034hpack==4.1.035httpcore==1.0.736httptools==0.6.437httpx==0.28.138httpx-sse==0.4.039huggingface-hub==0.28.140hyperframe==6.1.041idna==3.1042jiter==0.8.243jmespath==1.0.144jsonpath-python==1.0.645logfire-api==3.5.046multidict==6.1.047mypy-extensions==1.0.048ollama==0.4.749openai==1.61.050packaging==24.251passlib==1.7.452Pillow==10.1.053postgrest==0.19.354propcache==0.2.155pyasn1==0.6.156pyasn1_modules==0.4.157pycparser==2.2258pydantic-ai==0.0.2159pydantic_core==2.27.260python-dateutil==2.9.0.post061python-dotenv==1.0.062python-jose==3.3.063python-magic==0.4.2764python-multipart==0.0.665PyYAML==6.0.266realtime==2.3.067requests==2.32.368rsa==4.969s3transfer==0.7.070six==1.17.071sniffio==1.3.172SQLAlchemy==2.0.2373storage3==0.11.374StrEnum==0.4.1575supabase==2.12.076supafunc==0.9.377tokenizers==0.21.078tqdm==4.67.179types-requests==2.32.0.2024101680typing-inspect==0.9.081typing_extensions==4.12.282urllib3==2.0.783uvicorn==0.30.684uvloop==0.21.085watchfiles==1.0.486websockets==12.087yarl==1.18.3

I would be thankful if anyone helped me with solving the issue. I suspect there might be an issue with pydantic v2.x but I can't use older version due to other dependencies.