Seedream 4.0 API documentation

Integrate Seedream 4.0 with your VezAPI key. The operations below share the same authentication and account balance.

Base URL: https://api.vezapi.com
Send Authorization: Bearer YOUR_VEZAPI_KEY. Use a unique Idempotency-Key for each submission; reuse it only when checking the same request.

Seedream4.0 - Edit

POST/api/v1/jobs/createTask

Model IDs: bytedance/seedream-v4-edit

Parameter	Type	Description & constraints
`model` required	`string`	The model name to use for generation. Required field. - Must be `bytedance/seedream-v4-edit` for this endpoint Values: `"bytedance/seedream-v4-edit"` Default: `"bytedance/seedream-v4-edit"`
`callBackUrl` optional	`string`	The URL to receive generation task completion updates. Optional but recommended for production use. - System will POST task status and results to this URL when generation completes - Callback includes generated content URLs and task information - Your callback endpoint should accept POST requests with JSON payload containing results - Alternatively, use the Get Task Details endpoint to poll task status - To ensure callback security, see [Webhook Verification Guide](/common-api/webhook-verification) for signature verification implementation
`input` optional	`object`	Input parameters for the generation task
`input.prompt` required	`string`	The text prompt used to edit the image (Max length: 5000 characters) `maxLength: 5000`
`input.image_urls` required	`array`	List of URLs of input images for editing. Presently, up to 10 image inputs are allowed. (File URL after upload, not file content; Accepted types: image/jpeg, image/png, image/webp; Max size: 30.0MB) `maxItems: 10`
`input.image_size` optional	`string`	The size of the generated image. Values: `"square", "square_hd", "portrait_4_3", "portrait_3_2", "portrait_16_9", "landscape_4_3", "landscape_3_2", "landscape_16_9", "landscape_21_9"` Default: `"square_hd"`
`input.image_resolution` optional	`string`	Final image resolution is determined by combining image_size (aspect ratio) and image_resolution (pixel scale).. Values: `"1K", "2K", "4K"` Default: `"1K"`
`input.max_images` optional	`number`	Set this value (1–6) to cap how many images a single generation run can produce in one set—because they’re created in one shot rather than separate requests, you must also state the exact number you want in the prompt so both settings align. (Min: 1, Max: 6, Step: 1) (step: 1) Default: `1` `minimum: 1` `maximum: 6`
`input.seed` optional	`integer`	Random seed for reproducible results. Integer, up to 1000000. Omit for a random seed. `maximum: 1000000`
`input.nsfw_checker` optional	`boolean`	Defaults to false. When false, no additional content filtering is applied and results are returned directly by the model.

Request example

curl -X POST 'https://api.vezapi.com/api/v1/jobs/createTask' \
  -H 'Authorization: Bearer YOUR_VEZAPI_KEY' \
  -H 'Idempotency-Key: your-unique-request-id' \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "bytedance/seedream-v4-edit",
  "input": {
    "prompt": "Refer to this logo and create a single visual showcase for an outdoor sports brand named ‘KIE AI’. Display five branded items together in one image: a packaging bag, a hat, a carton box, a wristband, and a lanyard. Use blue as the main visual color, with a fun, simple, and modern style.",
    "image_urls": [
      "https://example.com/input.png"
    ]
  }
}'

Responses and errors

HTTP 200

Request successful

Parameter	Type	Description & constraints
`code` optional	`integer`	Status code of the request. The HTTP status is 200 even when the request fails, so always check this field: 200 means success; any other value means the request failed and msg describes the reason. Common values: 401 invalid or missing API key; 402 insufficient credits; 429 rate limit exceeded; 422 or 500 the request could not be processed (read msg and check your parameters before retrying). Values: `200, 401, 402, 404, 422, 429, 433, 455, 500, 501, 505`
`msg` optional	`string`	Response message, error description upon failure
`data` required	`object`
`data.taskId` required	`string`	The task ID can be used with the "Get Task Details" endpoint to query the task status.

HTTP 500

Server error.

Parameter	Type	Description & constraints
`code` required	`integer`	Response status code - 200: Success - Request has been processed successfully - 401: Unauthorized - Authentication credentials are missing or invalid - 402: Insufficient Credits - Account does not have enough credits to perform the operation - 404: Not Found - The requested resource or endpoint does not exist - 408: Timeout - No result has been returned for over 10 minutes. - 422: Validation Error - The request parameters failed validation checks - 429: Rate Limited - Request limit has been exceeded for this resource - 455: Service Unavailable - System is currently undergoing maintenance - 500: Server Error - An unexpected error occurred while processing the request - 501: Generation Failed - Content generation task failed - 505: Feature Disabled - The requested feature is currently disabled
`msg` required	`string`	Response message, error description when failed
`data` required	`object`

Seedream4.0 - Text to Image

POST/api/v1/jobs/createTask

Model IDs: bytedance/seedream-v4-text-to-image

Parameter	Type	Description & constraints
`model` required	`string`	The model name to use for generation. Required field. - Must be `bytedance/seedream-v4-text-to-image` for this endpoint Values: `"bytedance/seedream-v4-text-to-image"` Default: `"bytedance/seedream-v4-text-to-image"`
`callBackUrl` optional	`string`	The URL to receive generation task completion updates. Optional but recommended for production use. - System will POST task status and results to this URL when generation completes - Callback includes generated content URLs and task information - Your callback endpoint should accept POST requests with JSON payload containing results - Alternatively, use the Get Task Details endpoint to poll task status - To ensure callback security, see [Webhook Verification Guide](/common-api/webhook-verification) for signature verification implementation
`input` optional	`object`	Input parameters for the generation task
`input.prompt` required	`string`	The text prompt used to generate the image (Max length: 5000 characters) `maxLength: 5000`
`input.image_size` optional	`string`	The size of the generated image. Values: `"square", "square_hd", "portrait_4_3", "portrait_3_2", "portrait_16_9", "landscape_4_3", "landscape_3_2", "landscape_16_9", "landscape_21_9"` Default: `"square_hd"`
`input.image_resolution` optional	`string`	Final image resolution is determined by combining image_size (aspect ratio) and image_resolution (pixel scale).. Values: `"1K", "2K", "4K"` Default: `"1K"`
`input.max_images` optional	`number`	Set this value (1–6) to cap how many images a single generation run can produce in one set—because they’re created in one shot rather than separate requests, you must also state the exact number you want in the prompt so both settings align. (Min: 1, Max: 6, Step: 1) (step: 1) Default: `1` `minimum: 1` `maximum: 6`
`input.seed` optional	`integer`	Random seed for reproducible results. Integer, up to 1000000. Omit for a random seed. `maximum: 1000000`
`input.nsfw_checker` optional	`boolean`	Defaults to false. When false, no additional content filtering is applied and results are returned directly by the model.

Request example

curl -X POST 'https://api.vezapi.com/api/v1/jobs/createTask' \
  -H 'Authorization: Bearer YOUR_VEZAPI_KEY' \
  -H 'Idempotency-Key: your-unique-request-id' \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "bytedance/seedream-v4-text-to-image",
  "input": {
    "prompt": "Draw the following system of binary linear equations and the corresponding solution steps on the blackboard: 5x + 2y = 26; 2x -y = 5."
  }
}'

Responses and errors

HTTP 200

Request successful

Parameter	Type	Description & constraints
`code` optional	`integer`	Status code of the request. The HTTP status is 200 even when the request fails, so always check this field: 200 means success; any other value means the request failed and msg describes the reason. Common values: 401 invalid or missing API key; 402 insufficient credits; 429 rate limit exceeded; 422 or 500 the request could not be processed (read msg and check your parameters before retrying). Values: `200, 401, 402, 404, 422, 429, 433, 455, 500, 501, 505`
`msg` optional	`string`	Response message, error description upon failure
`data` required	`object`
`data.taskId` required	`string`	The task ID can be used with the "Get Task Details" endpoint to query the task status.

HTTP 500

Server error.

Parameter	Type	Description & constraints
`code` required	`integer`	Response status code - 200: Success - Request has been processed successfully - 401: Unauthorized - Authentication credentials are missing or invalid - 402: Insufficient Credits - Account does not have enough credits to perform the operation - 404: Not Found - The requested resource or endpoint does not exist - 408: Timeout - No result has been returned for over 10 minutes. - 422: Validation Error - The request parameters failed validation checks - 429: Rate Limited - Request limit has been exceeded for this resource - 455: Service Unavailable - System is currently undergoing maintenance - 500: Server Error - An unexpected error occurred while processing the request - 501: Generation Failed - Content generation task failed - 505: Feature Disabled - The requested feature is currently disabled
`msg` required	`string`	Response message, error description when failed
`data` required	`object`

Task status and callbacks

For asynchronous tasks, keep the returned taskId. Query GET /api/v1/jobs/recordInfo?taskId=... or provide callBackUrl when creating the task. Only the account that created a task can access it or derive new resources from it.

A timeout can mean the submission was accepted. Inspect the existing request in your dashboard; do not create another task automatically. Callback delivery is retried and may arrive more than once. Deduplicate with X-VezAPI-Event-Id.

Files, logs and billing

Generated media normally follows a 14-day provider lifetime; uploaded files expire after 24 hours. Save the files you need before expiration. VezAPI streams registered files without keeping a permanent media library. Request logs are retained for two calendar months.

Credits are reserved before submission. Final deductions match actual discounted consumption one for one. Unknown usage pauses new paid requests. If available funds cannot cover final usage while protecting other reservations, settlement stays pending until funded; model usage cannot make the wallet negative. Time-based inputs require server-side metadata reads; a failed read prevents submission.