> ## 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. # Generate media with AI > Starts generating an image or a sound effect from a text prompt with the same AI generators the editor's media panels use. Generation is asynchronous: the response is a `generation` whose `id` is the private library item the result is saved as. Poll `GET /v1/library/generations/{id}` every few seconds (images usually take 30-90 seconds, sound effects 10-30) until `status` is `completed`, then pass `item.sourceId` anywhere a source is accepted — `POST /v1/videos/{id}/clips/{clipId}/overlays` for an image overlay, `POST /v1/videos/{id}/clips/{clipId}/layouts` with `media` for b-roll, `POST /v1/videos/{id}/clips/{clipId}/sound-effects` for a sound effect. The finished item also appears in `GET /v1/library?scope=private`. Each generation counts against the caller's weekly AI generation allowance, which depends on the plan; exceeding it answers 403 with the reset time. ## OpenAPI ````yaml /openapi.json post /v1/library/generations 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 user within a workspace. Rate limit information is returned in response headers: - `RateLimit-Policy`: Named quota, request limit, and window in seconds - `RateLimit`: Remaining quota and seconds until reset - `X-RateLimit-Limit`: Maximum requests per window - `X-RateLimit-Remaining`: Remaining requests in current window - `X-RateLimit-Reset`: Unix timestamp in milliseconds when the window resets A `429 Too Many Requests` response also includes `Retry-After` in seconds. 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: >- Viewing analytics for a video or across the workspace: plays, watch time, retention, geography, referrers name: Analytics - description: Personal, workspace, and default video backgrounds name: Backgrounds - description: >- Reusable media saved to a workspace, plus Tella's curated sound effect and background music catalogs — the same items the editor's media panels show name: Library - description: Webhook endpoint management name: Webhooks externalDocs: description: API versioning and deprecation policy url: https://www.tella.com/docs/versioning paths: /v1/library/generations: post: tags: - Library summary: Generate media with AI description: >- Starts generating an image or a sound effect from a text prompt with the same AI generators the editor's media panels use. Generation is asynchronous: the response is a `generation` whose `id` is the private library item the result is saved as. Poll `GET /v1/library/generations/{id}` every few seconds (images usually take 30-90 seconds, sound effects 10-30) until `status` is `completed`, then pass `item.sourceId` anywhere a source is accepted — `POST /v1/videos/{id}/clips/{clipId}/overlays` for an image overlay, `POST /v1/videos/{id}/clips/{clipId}/layouts` with `media` for b-roll, `POST /v1/videos/{id}/clips/{clipId}/sound-effects` for a sound effect. The finished item also appears in `GET /v1/library?scope=private`. Each generation counts against the caller's weekly AI generation allowance, which depends on the plan; exceeding it answers 403 with the reset time. operationId: createGeneration requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateGenerationRequest' required: true responses: '202': content: application/json: schema: $ref: '#/components/schemas/CreateGenerationResponse' description: Accepted headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '400': content: application/json: example: docsUrl: https://docs.tella.com/ error: 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. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '401': content: application/json: example: docsUrl: https://docs.tella.com/ error: unauthorized message: Authentication is required. Provide a valid API key. schema: $ref: '#/components/schemas/ErrorResponse' description: Authentication is required. Provide a valid API key. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '403': content: application/json: example: docsUrl: https://docs.tella.com/ error: 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. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '404': content: application/json: example: docsUrl: https://docs.tella.com/ error: not_found message: The requested resource was not found. schema: $ref: '#/components/schemas/ErrorResponse' description: The requested resource was not found. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '409': content: application/json: example: docsUrl: https://docs.tella.com/ error: conflict message: >- The request conflicts with the resource's current state, e.g. an Idempotency-Key whose first request is still in progress. Retry once it settles. schema: $ref: '#/components/schemas/ErrorResponse' description: >- The request conflicts with the resource's current state, e.g. an Idempotency-Key whose first request is still in progress. Retry once it settles. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '429': content: application/json: example: docsUrl: https://docs.tella.com/ error: rate_limited 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. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Retry-After: $ref: '#/components/headers/RetryAfter' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '500': content: application/json: example: docsUrl: https://docs.tella.com/ error: server_error message: An unexpected error occurred schema: $ref: '#/components/schemas/ErrorResponse' description: An unexpected error occurred headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '501': content: application/json: example: docsUrl: https://docs.tella.com/ error: not_implemented message: The requested operation is not implemented. schema: $ref: '#/components/schemas/ErrorResponse' description: The requested operation is not implemented. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' '503': content: application/json: example: docsUrl: https://docs.tella.com/ error: unavailable message: >- A dependency was unavailable and the request was not executed. Safe to resend unchanged after the Retry-After delay. schema: $ref: '#/components/schemas/ErrorResponse' description: >- A dependency was unavailable and the request was not executed. Safe to resend unchanged after the Retry-After delay. headers: Deprecation: $ref: '#/components/headers/Deprecation' RateLimit: $ref: '#/components/headers/RateLimit' RateLimit-Policy: $ref: '#/components/headers/RateLimitPolicy' Sunset: $ref: '#/components/headers/Sunset' X-RateLimit-Limit: $ref: '#/components/headers/XRateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/XRateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/XRateLimitReset' security: - BearerAuth: [] components: schemas: CreateGenerationRequest: additionalProperties: false description: Start generating media from a prompt properties: model: description: >- For `image` only: which GPT Image 2.5 model to use. `sunburst` (default) is the most capable and follows reference images most precisely; `flare` is faster. enum: - sunburst - flare example: flare type: string prompt: description: >- What to generate. Up to 4000 characters for an image, 2000 for a sound effect. example: A watercolor illustration of a lighthouse at dawn minLength: 1 type: string referenceSourceId: description: >- For `image` only: the `sourceId` of an image source to guide the generation — from `POST /v1/sources` (`kind: "image"`) after uploading the bytes, or an `image` library item's `sourceId`. example: su_abc123def456 type: string type: $ref: '#/components/schemas/GenerationType' required: - type - prompt type: object CreateGenerationResponse: additionalProperties: false description: The generation that was started, plus the weekly allowance properties: generation: $ref: '#/components/schemas/Generation' limit: description: >- The caller's weekly AI generation allowance for this media type, which depends on the plan example: 20 maximum: 9007199254740991 minimum: -9007199254740991 type: integer remaining: description: Generations left in the current week, after this one example: 19 maximum: 9007199254740991 minimum: -9007199254740991 type: integer resetAt: description: When the weekly allowance resets, as a millisecond epoch example: 1760000000000 type: number required: - generation - limit - remaining - resetAt type: object ErrorResponse: additionalProperties: false description: Standard error response format properties: docsUrl: description: Link to Tella API documentation example: https://docs.tella.com/ format: uri type: string error: description: Machine-readable error code enum: - bad_request - unauthorized - forbidden - not_found - rate_limited - server_error - conflict - edit_conflict - not_implemented - unavailable example: not_found type: string message: description: Human-readable error message example: Resource not found type: string required: - error - message - docsUrl type: object GenerationType: description: The kind of media to generate enum: - image - sound-effect example: image type: string Generation: additionalProperties: false description: An AI media generation and, once finished, its library item properties: error: description: >- A sanitized, human-readable reason when `status` is `failed`. It may identify a content-safety rejection or timeout, or report a generic failure. Do not parse this text for machine handling. type: string id: description: >- Generation ID. It is also the ID of the private library item the result is saved as, so it can be passed to `GET /v1/library/generations/{id}` to poll and shows up in `GET /v1/library?scope=private` once finished. example: mi_abc123def456 type: string item: allOf: - $ref: '#/components/schemas/LibraryItem' description: >- The finished library item, present once `status` is `completed`. Pass its `sourceId` anywhere a source is accepted — overlays, layout media, sound effects. prompt: description: The prompt the media is being generated from example: A watercolor illustration of a lighthouse at dawn type: string status: $ref: '#/components/schemas/GenerationStatus' type: $ref: '#/components/schemas/GenerationType' required: - id - type - status - prompt type: object LibraryItem: additionalProperties: false description: >- A placeable piece of media — either saved to a workspace's library, or an entry in Tella's curated catalog properties: category: description: >- Catalog grouping, for `default` items only — the same grouping the editor's sound effects and background music panels show example: Everyday type: string createdAt: description: >- ISO-8601 creation timestamp. Absent for `default` catalog items, which are served from Tella's catalog rather than stored as rows. type: string dimensions: additionalProperties: false description: Pixel dimensions, for visual media properties: height: maximum: 9007199254740991 minimum: -9007199254740991 type: integer width: maximum: 9007199254740991 minimum: -9007199254740991 type: integer required: - width - height type: object durationMs: description: Duration in milliseconds, for time-based media example: 4200 type: number id: description: Unique library item identifier example: media_abc123def456 type: string name: description: Display name shown in the library example: Intro camera take type: string presetId: description: >- Preset ID, for `default` catalog items only. A preset has no source, so pass this instead of `sourceId`: a `sound-effect` preset goes to `POST /v1/videos/{id}/clips/{clipId}/sound-effects` (placing it copies the effect into a source owned by your workspace), a `music` preset to `PUT /v1/videos/{id}/background-music`. example: cha-ching type: string scope: $ref: '#/components/schemas/LibraryReadScope' sourceId: description: >- Source ID. Pass it anywhere a `sourceId` is accepted — clips, layouts, overlays, sound effects. Present for every item added through this API, including images. Absent for items added in the editor, which have no source, for music and LUT items, and for `default` catalog items, which use `presetId` instead. example: su_abc123def456 type: string type: $ref: '#/components/schemas/LibraryItemType' updatedAt: description: ISO-8601 update timestamp. Absent for `default` catalog items. type: string url: description: >- Hosted media URL, for `image`, `screenshot`, `music` and `lut` items, and for `default` catalog items, where it is a publicly fetchable preview of the audio (for `music` presets it is also the track the video will play). API-created images expose this alongside `sourceId`; use `sourceId` to place the image on a clip, since overlays and layout media do not accept URLs. Editor-created `screenshot` items have a URL but no sourceId; use POST /v1/library/screenshots to capture a new placeable image or video. type: string required: - id - type - name - scope type: object GenerationStatus: description: >- `pending` and `running` mean the generator is still working — poll again in a few seconds. `completed` means `item` is ready to place. `failed` is final; start a new generation. enum: - pending - running - completed - failed example: completed type: string LibraryReadScope: description: >- Which set of media to read: `private` (only visible to their creator), `workspace` (shared with everyone in the workspace), or `default` (Tella's curated sound effect and background music catalogs, which hold no other media type) enum: - private - workspace - default example: private type: string LibraryItemType: description: The kind of media the item holds enum: - image - video - sound-effect - music - lut - screenshot example: video type: string headers: Deprecation: description: Indicates that an API operation is deprecated, following RFC 9745 example: '@1767225600' schema: type: string RateLimit: description: >- Current quota with remaining requests (`r`) and seconds until reset (`t`) example: '"public-api";r=95;t=42' schema: type: string RateLimitPolicy: description: >- Named quota policy with the request limit (`q`) and window in seconds (`w`) example: '"public-api";q=100;w=60' schema: type: string Sunset: description: >- Indicates when a deprecated API operation will become unavailable, following RFC 8594 example: Tue, 30 Jun 2026 23:59:59 GMT schema: type: string XRateLimitLimit: description: Maximum requests allowed in the current window example: 100 schema: type: integer XRateLimitRemaining: description: Requests remaining in the current window example: 95 schema: type: integer XRateLimitReset: description: Unix timestamp in milliseconds when the window resets example: 1704067200000 schema: format: int64 type: integer RetryAfter: description: Seconds to wait before retrying a rate-limited request example: 45 schema: minimum: 1 type: integer securitySchemes: BearerAuth: description: API key obtained from your Tella account settings scheme: bearer type: http ```` ## Related topics - [Media library API](/docs/media-library-api.md) - [Add media (B-roll)](/docs/help/editing/use-media.md) - [Add text to your video](/docs/help/editing/text-overlays.md) - [AI media generation](/docs/mcp-tools/ai-media-generation.md) - [Auto-generate layouts with AI](/docs/api-reference/clips/auto-generate-layouts-with-ai.md) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.