> ## Documentation Index > Fetch the complete documentation index at: https://heygen-1fa696a7.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Complete Asset Upload > Finalize a direct-to-S3 upload into a reusable asset. Call after the upload PUT returns 200. Idempotent: repeated calls return the same finalized asset. ## OpenAPI ````yaml /openapi/external-api.json post /v3/assets/{asset_id}/complete openapi: 3.1.0 info: title: HeyGen External API version: 1.0.0 description: >- HeyGen's external API for programmatic AI video creation. See https://docs.heygen.com for full documentation. contact: name: HeyGen Product Infra url: https://heygen.com servers: - url: https://api.heygen.com description: Production security: - ApiKeyAuth: [] - BearerAuth: [] tags: - name: Video Agent description: Create videos from text prompts using AI - name: Videos description: Create, list, retrieve, and delete videos - name: Templates description: Generate videos from reusable templates by replacing their variables - name: Voices description: Text-to-speech and voice management - name: Audio description: Search the background-music and sound-effects catalog - name: Video Translate description: Translate videos into other languages - name: AI Clipping description: Turn long-form videos into ready-to-share short clips with captions - name: Batches description: Create and track batches of videos. - name: Video Translation Batches description: Create and track batches of video translations. - name: Lipsync Batches description: Create and track batches of lipsyncs. - name: Asset Batches description: Create and track batches of direct-to-S3 asset uploads. - name: User description: Account information and billing - name: Avatars description: List and manage avatars and looks - name: Avatar Realtime description: >- Low-latency streaming avatar sessions — create a stream, poll for its HLS URL, push text, consume per-word timestamps - name: Assets description: Upload files for use in video creation - name: Webhooks description: Manage webhook endpoints and events - name: Lipsync description: Dub or replace audio on existing videos - name: Brand description: >- Brand-related resources — brand kits (colors, fonts, logos) and brand glossaries (custom term translations) - name: HyperFrames description: Render HyperFrames composition zips into video — separate from /v3/videos paths: /v3/assets/{asset_id}/complete: post: tags: - Assets summary: Complete Asset Upload description: >- Finalize a direct-to-S3 upload into a reusable asset. Call after the upload PUT returns 200. Idempotent: repeated calls return the same finalized asset. operationId: completeAssetUpload parameters: - name: asset_id in: path required: true schema: type: string description: Unique asset identifier requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CompleteAssetUploadRequest' responses: '200': description: Successful response content: application/json: schema: type: object properties: data: $ref: '#/components/schemas/CompleteAssetUploadResponse' '400': description: Invalid request parameters content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/StandardAPIError' '401': description: Authentication failed content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/StandardAPIError' example: error: code: authentication_failed message: Invalid or expired API key. Verify your x-api-key header. param: null doc_url: null '404': description: Resource not found content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/StandardAPIError' example: error: code: asset_not_found message: Asset not found. param: null doc_url: null '409': description: Conflict content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/StandardAPIError' example: error: code: conflict message: >- Uploaded object not found yet. Retry after the upload PUT returns 200. param: null doc_url: null '429': description: Rate limit exceeded content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/StandardAPIError' example: error: code: rate_limit_exceeded message: >- Too many requests. Retry after the duration specified in the Retry-After header. param: null doc_url: null headers: Retry-After: description: Seconds to wait before retrying schema: type: integer security: - ApiKeyAuth: [] - BearerAuth: [] components: schemas: CompleteAssetUploadRequest: description: Finalize a presigned upload (POST /v3/assets/{asset_id}/complete). properties: checksum_sha256: anyOf: - type: string - type: 'null' default: null description: Optional SHA256 (hex) cross-check. title: Checksum Sha256 title: CompleteAssetUploadRequest type: object CompleteAssetUploadResponse: description: Result of finalizing an upload. properties: asset_id: description: The reusable asset identifier. title: Asset Id type: string url: description: Public URL of the finalized asset. title: Url type: string mime_type: description: MIME type detected from the stored bytes. title: Mime Type type: string size_bytes: description: Size of the stored object in bytes. title: Size Bytes type: integer status: const: processing description: Asset status, e.g. 'processing'. title: Status type: string required: - asset_id - url - mime_type - size_bytes - status title: CompleteAssetUploadResponse type: object StandardAPIError: type: object properties: code: type: string description: Machine-readable error code example: invalid_parameter message: type: string description: Human-readable error message example: Video not found param: type: - string - 'null' description: Which request field caused the error doc_url: type: - string - 'null' description: Link to error documentation required: - code - message securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-api-key description: HeyGen API key. Obtain from your HeyGen dashboard. BearerAuth: type: http scheme: bearer description: OAuth2 bearer token. ````