OpenAI-Compatible Chat

OpenAI-compatible chat completions endpoint. Supports both standard (JSON) and streaming (SSE) responses. Rate-limited per API key.

Base URL

https://qolaba-server-b2b.up.railway.appqolaba-server-b2b.up.railway.app

Supported endpoints

Method	Path	Description
GET	/v1/models	List all available models
GET	/v1/models/{model}	Retrieve a specific model
POST	/api/v1/chat/completions	Create chat completions (streaming, tools, multimodal)

Chat Completions

POST /api/v1/chat/completions

Headers

Name	Value
Content-Type	application/json
Authorization	Bearer <token>

Body

Parameter	Type	Required	Description
model	string	Yes	The model ID to use for completion (e.g., "gpt-4o", "claude-3-5-sonnet"). Use GET /api/v1/chat/models to list available models.
messages	array	Yes	Ordered list of messages forming the conversation. Each object must have a role ("system", "user", or "assistant") and a content field (string or structured content array). Must contain at least one message.
stream	boolean	No	If true, the response is streamed as Server-Sent Events (SSE). Each event is a data: {...} line; the stream ends with data: [DONE]. Defaults to false.
temperature	number	No	Sampling temperature between 0 and 2. Higher values produce more random output; lower values are more deterministic. Defaults to 1.
max_tokens	integer	No	Maximum number of tokens to generate in the response. Must be a positive integer. If omitted, the model's default limit applies.
top_p	number	No	Nucleus sampling threshold between 0 and 1. The model considers only the tokens comprising the top top_p probability mass. An alternative to temperature; avoid adjusting both simultaneously.
frequency_penalty	number	No	Penalizes tokens based on how frequently they have appeared so far. Positive values reduce repetition. Typically between -2.0 and 2.0.
presence_penalty	number	No	Penalizes tokens that have appeared at all in the conversation so far. Positive values encourage the model to introduce new topics. Typically between -2.0 and 2.0.
stop	string | string[]	No	One or up to 4 sequences at which the model will stop generating further tokens. The stop sequence itself is not included in the output.
tool_choice	string | object	No	Controls which tool (if any) the model calls. Accepts "none", "auto".
stream_options	object	No	Additional options for streaming. Set { "include_usage": true } to receive a final SSE chunk containing token usage data. Automatically enabled when stream: true.

Request

{
  "model": "google/gemini-2.5-flash",
  "messages": [
    {
      "role": "user",
      "content": "What is the capital of France?"
    }
  ],
  "stream": false
}

Response (non-streaming)

200

{
  "id": "chatcmpl-4dd9fded095b4d86bceed1e91042a",
  "object": "chat.completion",
  "created": 1774095579,
  "model": "google/gemini-2.5-flash",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Paris."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "total_credit": 0.25,
    "total_cost": 0.0012441,
    "breakdown": {
      "model": {
        "model": "google/gemini-2.5-flash",
        "credit": 0.25,
        "cost": 0.001244
      }
    }
  }
}

Response (streaming)

When stream: true, the response is a stream of SSE events:

200

data: {"id":"chatcmpl-fed9ce60c8d6469aafb665a11d505","object":"chat.completion.chunk","created":1774095604,"model":"google/gemini-2.5-flash","choices":[{"index":0,"delta":{"role":"assistant"},"finish_reason":null}]}

data: {"id":"chatcmpl-fed9ce60c8d6469aafb665a11d505","object":"chat.completion.chunk","created":1774095604,"model":"google/gemini-2.5-flash","choices":[{"index":0,"delta":{"content":"Paris."},"finish_reason":null}]}

data: {"id":"chatcmpl-fed9ce60c8d6469aafb665a11d505","object":"chat.completion.chunk","created":1774095604,"model":"google/gemini-2.5-flash","choices":[{"index":0,"delta":{},"finish_reason":"stop"}]}

data: [DONE]

data: {"usage":{"total_credit":0.25,"total_cost":0.0012441,"breakdown":{"model":{"model":"google/gemini-2.5-flash","credit":0.25,"cost":0.001244}}}}

Error Responses

Status	Condition
400	model is missing
400	messages is missing, not an array, or empty
400	temperature is outside 0–2
400	top_p is outside 0–1
400	max_tokens is not a positive integer
400	stop array contains more than 4 sequences
429	Rate limit exceeded
504	Request timed out (3-minute upstream limit)
502	Upstream provider error or invalid response
500	Internal server error

---

Related Endpoints

• GET /api/v1/chat/models — Returns the list of available models

Run the API

To test this API, please use the following link:

https://app.theneo.io/api-runner/qolaba/ml-apis/api-reference/chat-copyapp.theneo.io