Source Code
HeyGen API
AI avatar video creation API for generating talking-head videos, explainers, and presentations.
Default Workflow
Prefer Video Agent API (POST /v1/video_agent/generate) for most video requests.
Always use prompt-optimizer.md guidelines to structure prompts with scenes, timing, and visual styles.
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
| Task | Read |
|---|---|
| Generate video from prompt (easy) | prompt-optimizer.md → video-agent.md |
| Generate video with precise control | video-generation.md, avatars.md, voices.md |
| Check video status / get download URL | video-status.md |
| Add captions or text overlays | captions.md, text-overlays.md |
| Transparent video for compositing | video-generation.md (WebM section) |
| Generate standalone TTS audio | text-to-speech.md |
| Translate/dub existing video | video-translation.md |
| Use with Remotion | remotion-integration.md |
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
- 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/video-translation.md - Translating videos and dubbing
- references/text-to-speech.md - Standalone TTS audio with Starfish model
- 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