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) |

| Real-time interactive avatar | streaming-avatars.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/streaming-avatars.md - Real-time interactive sessions
• 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