Make a Recall.ai bot speak or display output in the meeting (output media, output audio, chat messages)

Documented steps

1. Choose the mechanism: Output Media for continuous webpage-driven camera/screenshare (live voice agents), Output Audio for short pre-rendered mp3 clips, Send Chat Message for text. Ref: https://docs.recall.ai/docs/stream-media
2. Output Media at creation: set output_media.camera and/or output_media.screenshare to {"kind": "webpage", "config": {"url": "https://..."}} in POST /bot. Supported on Zoom, Google Meet, Microsoft Teams and Cisco Webex; not on Slack Huddles.
3. Output Media on demand: POST https://<region>.recall.ai/api/v1/bot/{id}/output_media/ with the same config while the bot is live, and stop it with DELETE on the same path with a body such as {"camera": true}. Ref: https://docs.recall.ai/reference/bot_output_media_create
4. Build the streamed webpage to read meeting audio via the browser MediaStream API and optionally consume live transcripts over the documented websocket; the page renders fixed at 1280x720 at 15fps and always shows video.
5. Output Audio: enable automatic_audio_output on the bot at creation (required even for later on-demand playback - use a silent clip if you do not want audio on join), then POST https://<region>.recall.ai/api/v1/bot/{id}/output_audio/ with {"kind": "mp3", "b64_data": "<base64 mp3>"}. Ref: https://docs.recall.ai/docs/output-audio-in-meetings
6. For a greeting or recording-disclosure clip with no API call at all, configure automatic_audio_output at creation with its debounce options so it replays as participants join.
7. Chat: POST https://<region>.recall.ai/api/v1/bot/{id}/send_chat_message/ with {"message": "...", "to": "everyone", "pin": false}. Ref: https://docs.recall.ai/reference/bot_send_chat_message_create
8. Zoom additionally supports to: 'host' / 'everyone_except_host' / a specific participant id; Google Meet supports pin; Teams accepts anchor-tag HTML links. Ref: https://docs.recall.ai/docs/sending-chat-messages
9. To post chat automatically without an API call, set chat.on_bot_join and chat.on_participant_join at bot creation.
10. Respect per-platform chat limits: Zoom and Teams up to 4096 characters, Google Meet 500; Cisco Webex and GoTo Meeting do not support bot chat.