On Brand

Make HeyGen output match your brand over the API. A brand kit carries your colors, fonts, and logo; a brand glossary controls how your custom terms are spoken and translated. Learn which endpoints accept each.

Two workspace records control how on-brand a generated video is, and they cover different halves of the problem:

• Brand kit — how the video looks. Your colors, fonts, and logo, applied to scene backgrounds, text treatments, chart palettes, and logo placement.
• Brand glossary — how the video sounds and reads. A list of your custom terms with the pronunciation each one should get, so HeyGen is spoken hey-jen and product names survive translation intact.

Both are authored in the HeyGen web app under Brand Kit and are read-only over the API — you list them, get their IDs, and pass those IDs when you create a video. There is no endpoint that creates or edits either one.

API reference: List Brand Kits · List Brand Glossaries · Get Brand Glossary

Which endpoint takes which

The two IDs go to different endpoints, and no endpoint accepts both. Video Agent is the only consumer of a brand kit; everything that turns a written script into speech takes a glossary instead.

Endpoint	Field	What it does
POST /v3/video-agents	brand_kit_id	Applies your colors, fonts, and logo to every scene the agent composes.
POST /v3/video-agents/{session_id}	brand_kit_id	Re-brands an interactive session on a follow-up message, without starting over.
POST /v3/videos with "type" of studio, avatar, or image	brand_glossary_id	Sets pronunciation wherever audio is synthesized from a script: every Studio scene, or the single scene of an avatar or image video. Not accepted on cinematic_avatar, which has no script or voice.
POST /v3/videos/batches	brand_glossary_id	Same, set per item inside videos. Batch items are avatar or image; a studio item is rejected by this endpoint.
POST /v3/templates/{template_id}	brand_glossary_id	Sets pronunciation in the speech generated for a template.
POST /v3/video-translations	brand_glossary_id	Fixes how your terms are carried into the translated script.
POST /v3/video-translations/batches	brand_glossary_id	Same, set per item inside video_translations.
POST /v3/video-translations/proofreads	brand_glossary_id	Applies your terms to the editable subtitles a proofread session returns.

A brand kit reaches a Studio or Templates video the other way around: build the look into the composition or the template itself, then use a glossary for the audio.

Scope of each field

brand_kit_id and brand_glossary_id are both global to the request — one value per call, applied to everything it produces. In a translation batch or a video batch the glossary is per item, so a single batch can send different glossaries to different videos.

On POST /v3/videos, brand_glossary_id applies to the studio, avatar, and image composition types. It takes effect only where speech is synthesized from a script, so a caller-supplied audio_url or audio_asset_id is unaffected, and captions keep the original script wording either way. cinematic_avatar does not accept the field, because it has no script or voice: motion and speech are driven by the prompt and its reference assets.

Both IDs are workspace-scoped

A brand kit or glossary is visible only to API keys belonging to the workspace that owns it. IDs are 32-character hex strings with no prefix:

{
  "brand_kit_id": "3f9a1c47b8e24d5fa0c61e8b7d24f6a1",
  "brand_glossary_id": "8c2d5e91a47b4f3c8d1e6a9b2f5c7d40"
}

An ID that does not exist in the caller’s workspace is rejected when the request is made, so a bad ID costs you nothing — no video is created and no credits are consumed. If a valid-looking ID is rejected, confirm the API key belongs to the same workspace that owns the record.

Combining brand with a style

For Video Agent, brand_kit_id and style_id are independent and compose: a style picks the look — scene layout, pacing, aesthetic — and the brand kit makes that look yours. Use a style for the shape of the video and a brand kit to make it recognizably you.