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POST
/
v1
/
chat
/
completions
Image Analysis
curl --request POST \
  --url https://gptproto.com/v1/chat/completions \
  --header 'Authorization: <authorization>' \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "<string>",
  "messages": [
    {}
  ],
  "stream": true
}'
{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1699896916,
  "model": "gpt-5-nano",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "The image shows a wooden boardwalk path extending through a lush green grassland. The boardwalk appears to lead toward a distant tree line under a bright blue sky with some clouds. The grass on either side of the boardwalk is vibrant green, suggesting it might be spring or summer. The scene has a peaceful, natural atmosphere with good visibility and sunny weather conditions."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 1250,
    "completion_tokens": 89,
    "total_tokens": 1339
  }
}

​
Overview

This endpoint provides image analysis functionality using the OpenAI-compatible chat completions API. Upload images or provide image URLs to analyze and understand image content with vision-enabled models.

​
Authentication

This endpoint requires authentication using a Bearer token.
​
Authorization
string
default:"sk-***********"
required
Your API key in the format: sk-*****

​
Request Body

​
model
string
default:"gpt-5-nano"
required
The model to use for the request. Must be a vision-enabled model.
​
messages
array
required
Array of message objects for the conversation. Each message contains:
  • role: “user” or “assistant”
  • content: Can be a string or an array of content objects supporting:
    • text: Text content with type: "text" and text field
    • image_url: Image content with type: "image_url" and nested image_url object containing:
      • url: HTTP/HTTPS URL to the image
      • Supported formats: JPG, PNG, WebP, GIF
​
stream
boolean
default:false
Whether to stream the response

​
Request Example

curl -X POST "https://gptproto.com/v1/chat/completions" \
  -H "Authorization: sk-*****" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gpt-5-nano",
  "messages": [
    {
      "role": "user",
      "content": [
        {
          "type": "text",
          "text": "What is in this image?"
        },
        {
          "type": "image_url",
          "image_url": {
            "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg"
          }
        }
      ]
    }
  ],
}'

​
Response

​
id
string
Unique identifier for the chat completion
​
object
string
Object type, always “chat.completion”
​
created
integer
Unix timestamp of when the chat completion was created
​
model
string
The model used for generating the completion
​
choices
array
Array of completion choices
​
usage
object
Token usage statistics
{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1699896916,
  "model": "gpt-5-nano",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "The image shows a wooden boardwalk path extending through a lush green grassland. The boardwalk appears to lead toward a distant tree line under a bright blue sky with some clouds. The grass on either side of the boardwalk is vibrant green, suggesting it might be spring or summer. The scene has a peaceful, natural atmosphere with good visibility and sunny weather conditions."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 1250,
    "completion_tokens": 89,
    "total_tokens": 1339
  }
}