Agent video track not displayed in Playground after Dec 21 Agent SDK update (commit 4d300ac)

[pramodshanmugam]

Describe the bug

Description
After the Agent SDK update on Dec 21, 2025 (commit 4d300ac), the LiveKit Playground no longer displays video tracks from agent participants that connect using the Go SDK. Audio tracks work correctly, but video tracks are filtered out despite being successfully published.

Environment

• LiveKit Playground: agents-playground.livekit.io (post-Dec 21 update)
• Agent SDK: Go SDK (github.com/livekit/server-sdk-go/v2 v2.13.0)
• LiveKit Protocol: v1.43.2
• Browser: Chrome/Firefox (tested on both)

Expected Behavior
Agent video track should be displayed in the Playground, similar to how it works in LiveKit Meet.

Actual Behavior

• Audio track is subscribed and works correctly
• Video track is published but not displayed in Playground UI
• Video track works correctly in LiveKit Meet and other clients

Logs/Evidence

Reproduction

Steps to Reproduce

1. Connect to LiveKit room as an agent using Go SDK with proper configuration:
   • ParticipantKind: lksdk.ParticipantAgent
   • ParticipantAttributes: {"lk.agent": "true"}
   • Publish video track with Source: livekit.TrackSource_CAMERA
2. Open LiveKit Playground and join the same room
3. Observe that audio is visible but video shows "Waiting for agent video track..."

Logs

System Info

OS: MAC M4
Browser: Chrome
LiveKit SDK: Go server-sdk-go/v2 v2.13.0
LiveKit Protocol: v1.43.2
Client: agents-playground.livekit.io (accessed Dec 31, 2025)

Severity

blocking an upgrade

Additional Information

No response