Basic checks

• I searched existing issues - this hasn't been reported
• I can reproduce this consistently
• This is a RubyLLM bug, not my application code

What's broken?

When using OpenAI's word-level timestamp granularities feature, the words field from the API response was silently ignored. Users couldn't access word-level timing data even though OpenAI's API was returning it.

How to reproduce

1. Call transcribe with timestamp_granularities

  transcription = RubyLLM.transcribe(
    'audio.wav',
    model: 'whisper-1',
    provider: :openai,
    timestamp_granularities: ['word'],
    response_format: 'verbose_json'
  )

2. OpenAI API returns response with 'words' array containing:

[
  {"word": "Hello", "start": 0.0, "end": 0.5},
  {"word": "world", "start": 0.6, "end": 1.0}
]

3. Try to access the words data

transcription.words
# => undefined method `words' for an instance of RubyLLM::Transcription

The Transcription class was missing:

• words attribute reader
• @words instance variable assignment in initializer

Expected behavior

When calling RubyLLM.transcribe with timestamp_granularities: ['word'], the returned Transcription object should provide access to word-level timing data via the words attribute:

  transcription = RubyLLM.transcribe(
    'audio.wav',
    model: 'whisper-1',
    provider: :openai,
    timestamp_granularities: ['word'],
    response_format: 'verbose_json'
  )

  transcription.words
  # => [
  #   {"word" => "Hello", "start" => 0.0, "end" => 0.5},
  #   {"word" => "world", "start" => 0.6, "end" => 1.0}
  # ]

What actually happened

The words data is silently dropped and inaccessible:

  transcription.words
  # => undefined method `words' for an instance of RubyLLM::Transcription

The OpenAI API successfully returns the words array in the response, but:

1. The Transcription class has no words attribute reader
2. The @words instance variable is never assigned
3. The data is lost even though the provider attempts to pass it

Environment

• RubyLLM version: 1.9.1
• Ruby version: 3.3.4
• Provider: OpenAI
• Model: whisper-1
• API feature: Word-level timestamp granularities