> ## Documentation Index > Fetch the complete documentation index at: https://www.tella.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Set a video's thumbnail > Sets the video's thumbnail from either an uploaded image or a frame of the video itself. Provide exactly one of `sourceId` (an image source from `POST /v1/sources` with `kind: "image"` — upload the image bytes to its `uploadUrl` first) or `inpointMs` (a time on the video's playback timeline). Setting one mode clears the other. ## OpenAPI ````yaml /openapi.json put /v1/videos/{id}/thumbnail openapi: 3.0.3 info: description: >- The Tella Public API allows you to programmatically access your videos and playlists, including transcripts, chapters, and thumbnails. ## Authentication All requests require a Bearer token in the Authorization header: ``` Authorization: Bearer tella_pk_xxxxx... ``` API keys can be generated in your Tella workspace settings. ## Rate Limiting The API is rate-limited to 100 requests per minute per organization. Rate limit information is returned in response headers: - `X-RateLimit-Limit`: Maximum requests per window - `X-RateLimit-Remaining`: Remaining requests in current window - `X-RateLimit-Reset`: Unix timestamp when the window resets title: Tella Public API version: 1.0.0 servers: - description: Production url: https://api.tella.com security: [] tags: - description: Video operations name: Videos - description: Sections of a video name: Clips - description: Playlist operations name: Playlists - description: Sidebar groups for organizing playlists name: Playlist Groups - description: Tags for categorizing and filtering videos name: Tags - description: Webhook endpoint management name: Webhooks paths: /v1/videos/{id}/thumbnail: put: tags: - Videos summary: Set a video's thumbnail description: >- Sets the video's thumbnail from either an uploaded image or a frame of the video itself. Provide exactly one of `sourceId` (an image source from `POST /v1/sources` with `kind: "image"` — upload the image bytes to its `uploadUrl` first) or `inpointMs` (a time on the video's playback timeline). Setting one mode clears the other. operationId: setVideoThumbnail parameters: - description: Unique video identifier in: path name: id required: true schema: description: Unique video identifier example: vid_abc123def456 type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/SetVideoThumbnailRequest' responses: '200': content: application/json: schema: $ref: '#/components/schemas/SetVideoThumbnailResponse' description: Thumbnail set successfully '400': $ref: '#/components/responses/400ErrorResponse' '401': $ref: '#/components/responses/401ErrorResponse' '403': $ref: '#/components/responses/403ErrorResponse' '404': $ref: '#/components/responses/404ErrorResponse' '422': $ref: '#/components/responses/422ErrorResponse' '429': $ref: '#/components/responses/429ErrorResponse' '500': $ref: '#/components/responses/500ErrorResponse' security: - BearerAuth: [] components: schemas: SetVideoThumbnailRequest: additionalProperties: false description: >- Request body for setting a video's thumbnail. Provide exactly one of sourceId (uploaded image) or inpointMs (frame from the video). properties: inpointMs: description: >- Pick a video frame as the thumbnail: time in ms on the video's playback timeline (cuts applied, cumulative across clips). Clears any previously uploaded thumbnail image. Mutually exclusive with sourceId. example: 4500 maximum: 9007199254740991 minimum: 0 type: integer sourceId: description: >- Use an uploaded image as the thumbnail. Source ID from POST /v1/sources (kind: 'image'); upload the image bytes to the source's uploadUrl first. Mutually exclusive with inpointMs. example: su_abc123def456 minLength: 1 type: string type: object SetVideoThumbnailResponse: additionalProperties: false description: The thumbnail that was set properties: customThumbnailURL: description: >- CDN URL of the uploaded thumbnail image. Only present when the thumbnail was set from a sourceId. example: https://ucarecdn.com/12345678-abcd-4ef0-9012-3456789abcde/ type: string inpointMs: description: >- The thumbnail frame time in ms. Only present when the thumbnail was set from an inpointMs. example: 4500 maximum: 9007199254740991 minimum: -9007199254740991 type: integer type: object ErrorResponse: additionalProperties: false description: Standard error response format properties: error: additionalProperties: false description: Error details properties: code: description: Machine-readable error code enum: - bad_request - unauthorized - forbidden - not_found - unprocessable_entity - rate_limit_exceeded - internal_server_error example: not_found type: string doc_url: description: Link to documentation for this error example: https://tella.tv/docs/api-reference/errors#not-found format: uri type: string message: description: Human-readable error message example: The requested resource was not found. type: string required: - code - message - doc_url type: object required: - error type: object responses: 400ErrorResponse: content: application/json: example: error: code: bad_request doc_url: https://tella.tv/docs/api-reference/errors#bad-request message: The request was malformed or contained invalid parameters. schema: $ref: '#/components/schemas/ErrorResponse' description: The request was malformed or contained invalid parameters. 401ErrorResponse: content: application/json: example: error: code: unauthorized doc_url: https://tella.tv/docs/api-reference/errors#unauthorized message: Authentication is required. Provide a valid API key. schema: $ref: '#/components/schemas/ErrorResponse' description: Authentication is required. Provide a valid API key. 403ErrorResponse: content: application/json: example: error: code: forbidden doc_url: https://tella.tv/docs/api-reference/errors#forbidden message: You don't have permission to access this resource. schema: $ref: '#/components/schemas/ErrorResponse' description: You don't have permission to access this resource. 404ErrorResponse: content: application/json: example: error: code: not_found doc_url: https://tella.tv/docs/api-reference/errors#not-found message: The requested resource was not found. schema: $ref: '#/components/schemas/ErrorResponse' description: The requested resource was not found. 422ErrorResponse: content: application/json: example: error: code: unprocessable_entity doc_url: https://tella.tv/docs/api-reference/errors#unprocessable-entity message: The request was well-formed but contained semantic errors. schema: $ref: '#/components/schemas/ErrorResponse' description: The request was well-formed but contained semantic errors. 429ErrorResponse: content: application/json: example: error: code: rate_limit_exceeded doc_url: https://tella.tv/docs/api-reference/errors#rate-limit-exceeded message: You have exceeded the rate limit. Please slow down. schema: $ref: '#/components/schemas/ErrorResponse' description: You have exceeded the rate limit. Please slow down. 500ErrorResponse: content: application/json: example: error: code: internal_server_error doc_url: https://tella.tv/docs/api-reference/errors#internal-server-error message: An unexpected error occurred on the server. schema: $ref: '#/components/schemas/ErrorResponse' description: An unexpected error occurred on the server. securitySchemes: BearerAuth: description: API key obtained from your Tella account settings scheme: bearer type: http ````