SDK import fails when .env file contains non-MarketData variables

[MarketDataApp]

Description

The SDK cannot be imported in applications that have other environment variables defined in their .env file. This prevents the SDK from being used in multi-service applications.

Root Cause

The MarketDataSettings class in settings.py uses pydantic-settings which defaults to extra='forbid' when parsing .env files. This causes a ValidationError when ANY environment variable exists in .env that isn't explicitly defined in the model.

Reproduction

1. Create a .env file with any variable not defined by MarketData:

   MY_APP_KEY=123
   REDIS_HOST=localhost
   

2. Try to import the SDK:

   from marketdata.client import Client

3. Import fails immediately:

   pydantic_core._pydantic_core.ValidationError: 2 validation errors for MarketDataSettings
   my_app_key
     Extra inputs are not permitted [type=extra_forbidden, input_value='123', input_type=str]
   redis_host
     Extra inputs are not permitted [type=extra_forbidden, input_value='localhost', input_type=str]
   

Impact

• SDK is unusable in any application with other environment variables in .env
• Prevents integration with frameworks like Django, Flask, FastAPI that use their own env vars
• Breaks in containerized environments where multiple services share .env files
• Error occurs at module load time, before any client code can run

Suggested Fix

Add extra='ignore' to the model configuration in settings.py:

model_config = ConfigDict(
    env_file=".env",
    env_file_encoding="utf-8",
    extra='ignore'  # Allow other env vars to exist
)

Environment

• SDK version: v1.1.0
• Python: 3.13
• pydantic-settings: 2.x

[MarketDataDev02]

Added PR: #15

[MarketDataApp]

Fixed in v1.2.0 via PR #15.