feat: Intelligent Backchannel Interruption Handler - Pothamsetti Radha Krishna,NIT DURGAPUR

[rkpothamsetti]

Summary

• Implements context-aware interruption filtering that distinguishes passive acknowledgements (yeah, ok, hmm) from active interruptions (stop, wait, no) based on agent speaking state
• VAD-only interruptions deferred to STT when agent is speaking to prevent false-start pauses (no stutter)
• Semantic interruption support for mixed inputs (e.g. "yeah but wait" still interrupts)
• Configurable backchannel word list via AgentSessionOptions
• Provider fallback: OpenAI -> Groq for LLM/STT/TTS

Files Changed

• backchannel.py - New module for backchannel word detection with configurable ignore list
• agent_activity.py - Integrated state-based filtering into the interruption pipeline
• agent_session.py - Added configurable backchannel_words option to AgentSessionOptions
• interrupt_agent.py - Main agent entry point with provider fallback logic
• traces.py - Fixed OpenTelemetry import compatibility
• requirements.txt - Updated dependencies
• test_log.txt - Test proof log transcript
• INTERRUPT_HANDLER_README.md - Full documentation

Logic Matrix

User Says	Agent State	Action
Yeah / Ok / Hmm	Speaking	IGNORE (no pause, no stutter)
Stop / Wait / No	Speaking	INTERRUPT (agent stops immediately)
Yeah / Ok / Hmm	Silent	RESPOND (treat as valid input)
Yeah but wait	Speaking	INTERRUPT (semantic detection)

Test Results

All 4 scenarios verified in test_log.txt:

1. Backchannel while speaking -> IGNORED (no stutter)
2. Active interrupt while speaking -> INTERRUPTED
3. Backchannel while silent -> RESPONDED
4. Mixed input -> INTERRUPTED (semantic detection)