heygen

name: heygen description: | HeyGen AI video creation API. Use when: (1) Using Video Agent for one-shot prompt-to-video generation, (2) Generating AI avatar videos with /v2/video/generate, (3) Working with HeyGen avatars, voices, backgrounds, or captions, (4) Creating transparent WebM videos for compositing, (5) Polling video status or handling webhooks, (6) Integrating HeyGen with Remotion for programmatic video, (7) Creating photo avatars from images. homepage: https://docs.heygen.com/reference/generate-video-agent allowed-tools: mcp__heygen__* metadata: openclaw: requires: env: - HEYGEN_API_KEY primaryEnv: HEYGEN_API_KEY

HeyGen API

AI avatar video creation API for generating talking-head videos, explainers, and presentations.

Tool Selection

If HeyGen MCP tools are available (mcp__heygen__*), prefer them over direct HTTP API calls — they handle authentication and request formatting automatically.

If no HeyGen MCP tools are available, use direct HTTP API calls with X-Api-Key: $HEYGEN_API_KEY header as documented in the reference files.

Default Workflow

Prefer Video Agent for most video requests. Always use prompt-optimizer.md guidelines to structure prompts with scenes, timing, and visual styles.

With MCP tools:

1. Write an optimized prompt using prompt-optimizer.md → visual-styles.md
2. Call mcp__heygen__generate_video_agent with prompt and config (duration_sec, orientation, avatar_id)
3. Call mcp__heygen__get_video with the returned video_id to poll status and get the download URL

Without MCP tools (direct API):

1. Write an optimized prompt using prompt-optimizer.md → visual-styles.md
2. POST /v1/video_agent/generate — see video-agent.md
3. GET /v1/video_status.get?video_id=<id> — see video-status.md

Only use v2/video/generate when user explicitly needs:

• Exact script without AI modification
• Specific voice_id selection
• Different avatars/backgrounds per scene
• Precise per-scene timing control
• Programmatic/batch generation with exact specs

Quick Reference

Reference Files

Foundation

• references/authentication.md - API key setup and X-Api-Key header
• references/quota.md - Credit system and usage limits
• references/video-status.md - Polling patterns and download URLs
• references/assets.md - Uploading images, videos, audio

Core Video Creation

• references/avatars.md - Listing avatars, styles, avatar_id selection
• references/voices.md - Listing voices, locales, speed/pitch
• references/scripts.md - Writing scripts, pauses, pacing
• references/video-generation.md - POST /v2/video/generate and multi-scene videos
• references/video-agent.md - One-shot prompt video generation
• references/prompt-optimizer.md - Writing effective Video Agent prompts (core workflow + rules)
• references/visual-styles.md - 20 named visual styles with full specs
• references/prompt-examples.md - Full production prompt example + ready-to-use templates
• references/dimensions.md - Resolution and aspect ratios

Video Customization

• references/backgrounds.md - Solid colors, images, video backgrounds
• references/text-overlays.md - Adding text with fonts and positioning
• references/captions.md - Auto-generated captions and subtitles

Advanced Features

• references/templates.md - Template listing and variable replacement
• references/photo-avatars.md - Creating avatars from photos
• references/webhooks.md - Webhook endpoints and events

Integration

• references/remotion-integration.md - Using HeyGen in Remotion compositions