Image Captioning

Extract descriptive prompts or selling-point text from one or more images. Call it via REST API or MCP, or try it in the online playground.

CostEst. 47–57 credits / call

Try online

POST · https://api.nexscope.ai/ai/imageCaptioningMCP · nexscope_image_captioning

Subscription required. Creative AI APIs are available only to users with an active subscription. Trial credits do not enable API key access. View subscription plans.

Choose an integration method

Multimodal AI

What this API does

Extract descriptive prompts or selling-point text from one or more images. The request accepts type, imageUrlList, keyword, provider, refVideoUrl. Generation runs as a task: retain the task ID and retrieve the completed result before using the output.

Image Captioning API use cases

Prepare listing image assets

To prepare listing image assets, a content editor submits type and imageUrlList to Image Captioning. The returned completed generation results help prepare product visuals for a listing review.

Compare a product visual treatment

A content editor uses Image Captioning with type and imageUrlList to compare a product visual treatment. The returned completed generation results help compare the edited treatment with the source asset.

Review edited assets for a campaign

For this workflow, a content editor calls Image Captioning with type and imageUrlList to review edited assets for a campaign. The result helps select an approved asset for the campaign.

Image Captioning API FAQ

What does the Image Captioning API return?

Extract descriptive prompts or selling-point text from one or more images. It corresponds to the supplied type, imageUrlList, keyword, provider, refVideoUrl. The initial response can contain a task ID and status; the completed task result contains the generated output. Example values illustrate the response shape, rather than live account results.

How many credits does the Image Captioning API cost?

The current documented cost is Est. 47–57 credits / call. This is the same cost shown at the top of this page. If a range or estimate is displayed, the final charge depends on the request. Review your available credits and the pricing page before calling the API, and check API usage records for the actual charge.

How do I call the Image Captioning API from my app or an MCP client?

Send a POST request to https://api.nexscope.ai/ai/imageCaptioning with your API key as a Bearer token and the JSON inputs shown in API integration. In a compatible MCP client such as Claude or Cursor, connect Nexscope and call nexscope_image_captioning. Use the MCP arguments shown in the MCP guide, or switch Online test to MCP to review its request before adding it to your app.

View plans and credits Connect this API with MCP

Try this API

Endpoint

https://api.nexscope.ai/ai/imageCaptioning

MCP method

nexscope_image_captioning

Step 1 of 3 · Authenticate

Authentication

All run endpoints require a user API key. Send it as a bearer token in the Authorization header.

Authorization: Bearer nk-xxxxxxxxxxxxxxxxx

Missing or invalid API keys return an authentication error. Manage keys from .

Step 2 of 3 · Send a request

POSThttps://api.nexscope.ai/ai/imageCaptioning

Run an API

Extract descriptive prompts or selling-point text from one or more images.

Example request

Replace YOUR_API_KEY, then run this command in your terminal.

curl -X POST 'https://api.nexscope.ai/ai/imageCaptioning' \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "imageUrlList": [
    "https://example.com/product.jpg"
  ],
  "keyword": "phone case",
  "provider": "API_PRE_POINT",
  "type": 71
}'

Step 3 of 3 · Inspect the result

Check the response

Read code for the request status and data for the result. Open the parameter and response reference for the full field definitions.

HTTP status codes

Code	Description
200	HTTP request completed. Check JSON code; only 0 indicates business success or acceptance.
400	Request JSON or required API parameters are invalid.
401	API key is missing, invalid, or cannot be matched to a user.
5xx	API execution or upstream service failed.

View parameters & response Try online

All categories/ Multimodal AI

POSThttps://api.nexscope.ai/ai/imageCaptioning

Run this API

Send a JSON request to execute this API and receive the documented response payload.

Open tester

Endpoint

Method	`POST`
Path	`https://api.nexscope.ai/ai/imageCaptioning`
Auth	`Bearer API key`
Content-Type	`application/json`

Request parameters

Name	Type	Required	Description
`type`	`integer`	required	Analysis type. Available options `5 (similar-image prompt)` `13 (scene prompt)` `30 (image-to-video analysis)` `69 (apparel selling points)` `71 (product selling points)` `73 (sales-video script)` `89 (video-reclone prompt)` Example: 71
`imageUrlList`	`array`	required	Public image URLs used for analysis. Provide no more than 6 images for modes that accept multiple images. Example: [ "https://example.com/product.jpg" ]
`keyword`	`string`	optional	Optional keyword context. Example: phone case
`provider`	`string`	optional	Analysis provider. Available options `API_PRE_POINT (default)` `API_LAYOUT_DESC` Example: API_PRE_POINT
`refVideoUrl`	`string`	conditional	Reference video URL. Required when type is 89. Example: https://example.com/reference-video.mp4
`saleCountry`	`string`	optional	Target sale country code. Example: US
`targetLanguage`	`string`	optional	Target language for generated text. Used by video-reclone analysis. Example: English
`duration`	`integer`	optional	Target duration in seconds. Used by video-reclone analysis. Example: 15

Code example

{
  "imageUrlList": [
    "https://example.com/product.jpg"
  ],
  "keyword": "phone case",
  "provider": "API_PRE_POINT",
  "type": 71
}

Response example

Platform response envelope. code 0 indicates success or acceptance; data contains the business result.

{
  "code": 0,
  "cost": "-1",
  "data": {
    "result": null,
    "status": "PENDING",
    "taskId": "example-task"
  },
  "msg": null,
  "time": "2026-01-01 00:00:00",
  "traceId": null,
  "ts": "0"
}

Response fields

Name	Type	Required	Description
`code`	`integer`	required	0 means accepted or successful; nonzero is a platform error.
`cost`	`string`	required	Elapsed milliseconds, never credits; -1 outside web requests.
`data`	`any`	required	Data value used by this API operation.
`msg`	`string \| null`	required	Msg value used by this API operation.
`time`	`string`	required	Server local time: yyyy-MM-dd HH:mm:ss.
`traceId`	`string \| null`	required	Trace id value used by this API operation.
`ts`	`string`	required	Epoch milliseconds.

Any of option 1 — requires taskId, status, result

Name	Type	Required	Description
`data`	`object`	required	Data value used by this API operation.
`data.result`	`any`	required	Result value used by this API operation.
`data.status`	`string`	required	Status value used by this API operation. Allowed: PENDING, RUNNING, SUCCEEDED, FAILED, TIMEOUT
`data.taskId`	`string`	required	Task id value used by this API operation.
`data.usage`	`object`	optional	Actual credits charged for a completed successful task; omitted when unavailable.
`data.usage.chargedCredits`	`integer`	required	Charged credits value used by this API operation. Minimum: 0

Any of option 1

Name	Type	Required	Description
`data.result`	`object`	required	Completed generation output retained from the task result. Fields vary by capability; generated resources use Nexscope-hosted URLs and any count represents charged Nexscope credits. This is the business output, not a task creation receipt.

Any of option 2

Name	Type	Required	Description
`data.result`	`null`	required	Result value used by this API operation.

Any of option 2

Name	Type	Required	Description
`data`	`null`	required	Data value used by this API operation.

Responses

Code	Description
200	HTTP request completed. Check JSON code; only 0 indicates business success or acceptance.
400	Request JSON or required API parameters are invalid.
401	API key is missing, invalid, or cannot be matched to a user.
5xx	API execution or upstream service failed.

Step 1 of 2 · Connect your MCP client

MCP

V2 recommended

Connect remote agents through the standard MCP 2025-11-25 Streamable HTTP endpoint. Use OAuth 2.1 Authorization Code with PKCE, or an API key for compatibility.

POST https://api.nexscope.ai/mcp
MCP-Protocol-Version: 2025-11-25
Content-Type: application/json

Authentication

OAuth clients request the mcp:tools scope. The endpoint's 401 response advertises protected-resource metadata for authorization discovery.

Step 2 of 2 · Call the tool

Call a tool

{
  "jsonrpc": "2.0",
  "id": "tool-call-1",
  "method": "tools/call",
  "params": {
    "name": "nexscope_image_captioning",
    "arguments": {
      "imageUrlList": [
        "https://example.com/product.jpg"
      ],
      "keyword": "phone case",
      "provider": "API_PRE_POINT",
      "type": 71
    }
  }
}

Legacy MCP v1

Existing API-key clients can continue using the compatibility endpoint. New integrations should use MCP v2.

GET / POST /mcp/legacy

Online test

Execute the current API with your API key and JSON payload. Online tests use this site's configured API environment; the Endpoint and copyable examples use the public integration address.

Create with AI

Source images*Required

Public image URLs used for analysis. Provide no more than 6 images for modes that accept multiple images.

JPG, PNG, WEBP · Up to 6 images · 20 MB each

0/6

Reference videoOptional

Reference video URL. Required when type is 89.

MP4, MOV · 1 video · 20 MB

0/1

Video settings

Generation Mode*

Analysis type. Supported values: 5 (similar-image prompt), 13 (scene prompt), 30 (image-to-video analysis), 69 (apparel selling points), 71 (product selling points), 73 (sales-video script), 89 (video-reclone prompt).

Keywords

Optional keyword context.

Model

Analysis provider. Supported values: API_PRE_POINT (default), API_LAYOUT_DESC.

Sales Market

Target sale country code.

Target Language

Target language for generated text. Used by video-reclone analysis.

Duration

API keys require an active subscription. Trial credits don't include API access. View plans.

Usage estimate unavailable

Final credits are shown with your result.

Preview

Your video will appear here

Recent generations

Saved in this browser for 24 hours

Your generations will appear here.

Test with an API key or MCP

Try it

Send a real request with the same contract shown in the reference.

Endpoint

/ai/imageCaptioning

Task result endpoint

/ai/imageCaptioning/tasks/{taskId}

MCP method

nexscope_image_captioning

API key*

JSON payload*

cURL

curl -X POST \
  https://api.nexscope.ai/ai/imageCaptioning \
  -H "Authorization: Bearer nk-..." \
  -H "Content-Type: application/json" \
  -d '{ "imageUrlList": [], "keyword": "phone case", "provider": "API_PRE_POINT", "type": 71 }'

Response

No response yet. Run the request to see the response here.

Task result

Results are checked automatically after Run request. You can also enter a task ID and check it manually; completed resources use Nexscope URLs and show actual charged credits.

Task ID

Result response

No task result yet. Query the task to see the generated output here.

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