- --send-file <file.raw> sends a raw PCM file (48kHz mono s16le) through relay - Combine with --record: --send-file talk.raw --record echo.raw <relay> - Fixed all unused import warnings in echo_test.rs Convert any audio to test format: ffmpeg -i input.mp3 -ar 48000 -ac 1 -f s16le input.raw Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>