feat: add Runway Characters avatar plugin

[robinandeer]

Description

Add @livekit/agents-plugin-runway — an avatar plugin for Runway Characters (GWM-1 avatars). Follows the same pattern as the Bey/Anam/Lemonslice avatar plugins and mirrors the Python livekit-plugins-runway implementation (livekit/agents#5355).

Changes Made

• New plugin plugins/runway/ — AvatarSession class with preset or custom avatar support
• Sends livekit payload (url, token, roomName, agentIdentity) so Runway's avatar worker joins the agent's existing room
• Audio routed via DataStreamAudioOutput at 16kHz
• Sends User-Agent: @livekit/agents-plugin-runway/<version> header for server-side debugging
• Example agent examples/src/runway_avatar.ts using Gemini Realtime + Silero VAD
• Added Runway env vars to turbo.json globalEnv

Pre-Review Checklist

• Build passes: All builds (lint, typecheck, tests) pass locally
• AI-generated code reviewed: Removed unnecessary comments and ensured code quality
• Changes explained: All changes are properly documented and justified above
• Scope appropriate: All changes relate to the PR title
• Video demo: Tested manually against Runway staging API

Testing

• Plugin builds successfully
• Example agent connects to LiveKit room and starts Runway avatar session
• Manual testing against Runway realtime sessions API

Additional Notes

Environment variables needed:

• RUNWAYML_API_SECRET — Runway API key
• RUNWAYML_BASE_URL — (optional) Runway API URL, defaults to https://api.dev.runwayml.com
• RUNWAY_AVATAR_PRESET_ID — (optional) preset avatar ID, defaults to cat-character
• Standard LiveKit env vars (LIVEKIT_URL, LIVEKIT_API_KEY, LIVEKIT_API_SECRET)
• GOOGLE_API_KEY — for the example agent (Gemini Realtime)

---

Note to reviewers: Please ensure the pre-review checklist is completed before starting your review.

[changeset-bot]

🦋 Changeset detected

Latest commit: 1b6d004

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 25 packages

Name	Type
@livekit/agents-plugin-runway	Patch
@livekit/agents	Patch
@livekit/agents-plugin-anam	Patch
@livekit/agents-plugin-assemblyai	Patch
@livekit/agents-plugin-baseten	Patch
@livekit/agents-plugin-bey	Patch
@livekit/agents-plugin-cartesia	Patch
@livekit/agents-plugin-deepgram	Patch
@livekit/agents-plugin-elevenlabs	Patch
@livekit/agents-plugin-google	Patch
@livekit/agents-plugin-hedra	Patch
@livekit/agents-plugin-inworld	Patch
@livekit/agents-plugin-lemonslice	Patch
@livekit/agents-plugin-livekit	Patch
@livekit/agents-plugin-mistral	Patch
@livekit/agents-plugin-neuphonic	Patch
@livekit/agents-plugin-openai	Patch
@livekit/agents-plugin-phonic	Patch
@livekit/agents-plugin-resemble	Patch
@livekit/agents-plugin-rime	Patch
@livekit/agents-plugin-sarvam	Patch
@livekit/agents-plugin-silero	Patch
@livekit/agents-plugin-trugen	Patch
@livekit/agents-plugin-xai	Patch
@livekit/agents-plugins-test	Patch

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[toubatbrian]

@codex review and check the plugin package format against others. Compared with other avatar plugins and check for alignment or discrepancies

[toubatbrian]

Can we use ThrowsPromise here for error type safety

[robinandeer]

ThrowsPromise doesn't exist in the codebase — searched all of agents/ and plugins/ with no matches. No other avatar plugin (bey, trugen, hedra, lemonslice, anam) annotates error types on their methods either. Happy to add it if there's a utility type you have in mind, but for now this matches the existing plugin convention.

[toubatbrian]

Added a small comment, otherwise LGTM! You may also want to fix the linting issue by running pnpm run lint:fix

[tinalenguyen]

lgtm, thank you!