refactor: simplify callback inputs and add telemetry support

[silvestrid]

Summary

• Simplify callback inputs to use raw args/kwargs instead of inspecting function parameters
• Add provider field to OpenAILM for telemetry tracking
• Fix streaming parser to handle empty choices gracefully
• Improve adapter output validation logic for clarity

Motivation

These changes make it easier to integrate external telemetry libraries like PostHog by providing simpler, more flexible callback inputs and tracking which LM provider is being used.

Changes

• callback.py: Changed with_callbacks to pass raw args and kwargs instead of using inspect.getcallargs()
• lm/openai.py: Added provider parameter to OpenAILM class
• lm/factory.py: Pass provider parameter when creating OpenAILM instances
• adapter.py:
  • Added guard for empty choices in streaming parser
  • Improved readability of output validation logic

Test plan

• Verify existing tests pass
• Test callback functionality with PostHog or similar telemetry library
• Verify provider tracking works correctly
• Test streaming with various response formats

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR simplifies the callback system to support external telemetry integrations by passing raw function arguments instead of mapped parameters, adds provider tracking to OpenAILM for telemetry purposes, and includes defensive improvements to streaming response handling.

Key Changes

• Callback system now passes raw args and kwargs instead of using inspect.getcallargs() to map parameter names, making it simpler and more flexible for telemetry libraries
• Added provider field to OpenAILM class to track which LM provider is being used (e.g., "openai", "bedrock", "ollama")
• Improved streaming robustness with empty choices guard and clearer output validation logic

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/udspy/callback.py	Simplified callback inputs to pass raw args and kwargs instead of inspecting function signatures
src/udspy/lm/openai.py	Added provider parameter to OpenAILM for telemetry tracking
src/udspy/lm/factory.py	Updated LM factory to pass provider parameter when creating OpenAILM instances
src/udspy/adapter.py	Added defensive guard for empty choices in streaming and improved output validation readability
tests/test_callback.py	Updated test assertions to work with new callback input structure

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[Copilot]

The inputs structure has changed from flattened key-value pairs to {"kwargs": kwargs, "args": args}, but the docstrings in the BaseCallback class (lines 64, 94, and 124) still describe inputs as "Input arguments as key-value pairs" or "LLM input parameters". The documentation should be updated to reflect this new structure.

For example, the relevant docstrings should describe the new format:

inputs: Dict containing 'kwargs' and 'args' keys with the function's arguments