> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gptproto.com/llms.txt
> Use this file to discover all available pages before exploring further.
# gpt-5.5-pro (Text to Text (Chat))
## Authentication
1. Sign up for a GPTProto account at [https://gptproto.com](https://gptproto.com)
2. Navigate to the API Keys section in your dashboard
3. Generate a new API key (sk-xxxxx)
4. Copy and securely store your API key
For authentication details, please refer to the [Authentication](https://docs.gptproto.com/authentication) section.
## Initiate Request
```bash cURL theme={null}
curl --location 'https://gptproto.com/v1/chat/completions' \
--header 'Authorization: GPTPROTO_API_KEY' \
--header 'Content-Type: application/json' \
--data '{
"model": "gpt-5.5-pro",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"stream": false
}'
```
```javascript JavaScript theme={null}
const axios = require('axios');
let data = JSON.stringify({
"model": "gpt-5.5-pro",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"stream": false
});
let config = {
method: 'post',
maxBodyLength: Infinity,
url: 'https://gptproto.com/v1/chat/completions',
headers: {
'Authorization': 'GPTPROTO_API_KEY',
'Content-Type': 'application/json'
},
data : data
};
axios.request(config)
.then((response) => {
console.log(JSON.stringify(response.data));
})
.catch((error) => {
console.log(error);
});
```
```python Python theme={null}
import requests
import json
url = "https://gptproto.com/v1/chat/completions"
payload = json.dumps({
"model": "gpt-5.5-pro",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"stream": False
})
headers = {
'Authorization': 'GPTPROTO_API_KEY',
'Content-Type': 'application/json'
}
response = requests.request("POST", url, headers=headers, data=payload)
print(response.text)
```
```go Go theme={null}
package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://gptproto.com/v1/chat/completions"
method := "POST"
payload := strings.NewReader(`{
"model": "gpt-5.5-pro",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"stream": false
}`)
client := &http.Client {
}
req, err := http.NewRequest(method, url, payload)
if err != nil {
fmt.Println(err)
return
}
req.Header.Add("Authorization", "GPTPROTO_API_KEY")
req.Header.Add("Content-Type", "application/json")
res, err := client.Do(req)
if err != nil {
fmt.Println(err)
return
}
defer res.Body.Close()
body, err := io.ReadAll(res.Body)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(string(body))
}
```
## Parameters
### Core Parameters
| Parameter | Type | Required | Default | Range | Description |
| ---------------------------------- | -------------- | -------- | ------- | ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `model` | string | ✅ Yes | - | - | Model ID used to generate the response, like `gpt-4o` or `o3`. OpenAI offers a wide range of models with different capabilities, performance characteristics, and price points. Refer to the model guide to browse and compare available models. |
| `messages` | array | ✅ Yes | - | - | A list of messages comprising the conversation so far. Depending on the model you use, different message types (modalities) are supported, like text, images, and audio. |
| `>messages.role` | string | ✅ Yes | - | `developer`
`user`
`system` | The role of the messages author. |
| `>messages.name` | string | ❌ No | - | - | An optional name for the participant. Provides the model information to differentiate between participants of the same role. |
| `>messages.content` | string / array | ✅ Yes | - | - | The contents of the developer message. |
| `>>messages.content.type` | string | ✅ Yes | - | `text`
`image_url` | The type of the content part |
| `>>messages.content.text` | string | ❌ No | - | - | The text content |
| `>>messages.content.image_url` | object | ❌ No | - | - | The image URL content |
| `>>messages.content.image_url.url` | string | ❌ No | - | - | The URL of the image |
### Advanced Parameters
| Parameter | Type | Required | Default | Range | Description |
| ----------------------- | -------------- | -------- | ------- | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| `max_completion_tokens` | integer / null | ❌ No | - | - | An upper bound for the number of tokens that can be generated for a completion, including visible output tokens and reasoning tokens. |
| `stream` | boolean | ❌ No | `false` | `true`
`false` | Whether to stream the response back incrementally. Defaults to false. |
## Response Example
```json theme={null}
{
"id": "chatcmpl-abc123",
"object": "chat.completion",
"created": 1699896916,
"model": "gpt-5-chat",
"choices": [
{
"index": 0,
"message": {
"role": "assistant",
"content": "The image shows a wooden boardwalk path extending through a lush green grassland."
},
"finish_reason": "stop"
}
],
"usage": {
"prompt_tokens": 1250,
"completion_tokens": 89,
"total_tokens": 1339
}
}
```
## Error Codes
### Common Error Codes
| Error Code | Error Name | Description |
| ---------- | ------------------------ | ----------------------------------------------------------------------------------------------------------------- |
| 401 | Unauthorized | API key is missing or invalid |
| 403 | Forbidden | Your API key doesn't have permission to access this resource, or insufficient balance for the requested operation |
| 429 | Too Many Requests | You've exceeded your rate limit |
| 500 | Internal server error | An internal server error occurred |
| 503 | Content policy violation | Content blocked due to safety concerns (actual status code is 400) |