# Streaming events

Server-Sent Events (SSE) streamed when using `stream: true` in the request.

## Event Types

**`response.created`**

Sent when the response is created and processing begins.

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**`id`** string required

The response ID.

**`status`** string required

Always `in_progress`.

Example:


```json
{"id":"resp_abc123","status":"in_progress"}
```

**`response.output_item.added`**

Sent when a new output item (e.g., message) is added to the response.

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**`index`** integer required

The index of the output item.

**`item`** object required

The output item being added.

**`type`** string - The type of item (e.g., `message`)

Example:


```json
{"index":0,"item":{"type":"message"}}
```

**`response.output_text.delta`**

Sent for each text chunk as it's generated.

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**`index`** integer required

The index of the output item.

**`delta`** string required

The text chunk being streamed.

Example:


```json
{"index":0,"delta":"Hello"}
```

**`response.output_text.done`**

Sent when text generation is complete.

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**`text`** string required

The complete generated text.

Example:


```json
{"text":"Hello! How can I help you?"}
```

**`response.completed`**

Sent when the entire response is complete.

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**`status`** string required

Always `completed`.

Example:


```json
{"status":"completed"}
```

**`response.failed`**

Sent if the response fails.

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**`status`** string required

Always `failed`.

**`error`** object required

Error information.

Example:


```json
{"status":"failed","error":{"message":"Rate limit exceeded","code":"rate_limit"}}
```

## Usage

These events are streamed by:

- [Create a model response](/docs/api-reference/responses/create) - When `stream: true` is set


## Examples

Complete Stream

```
event: response.created
data: {"id":"resp_abc123","status":"in_progress"}

event: response.output_item.added
data: {"index":0,"item":{"type":"message"}}

event: response.output_text.delta
data: {"index":0,"delta":"Hello"}

event: response.output_text.delta
data: {"index":0,"delta":"! How can I"}

event: response.output_text.delta
data: {"index":0,"delta":" help you?"}

event: response.output_text.done
data: {"text":"Hello! How can I help you?"}

event: response.completed
data: {"status":"completed"}
```

With Error

```
event: response.created
data: {"id":"resp_abc123","status":"in_progress"}

event: response.output_item.added
data: {"index":0,"item":{"type":"message"}}

event: response.output_text.delta
data: {"index":0,"delta":"I'm proces"}

event: response.failed
data: {"status":"failed","error":{"message":"Rate limit exceeded","code":"rate_limit_exceeded"}}
```

Parsing in Python

```python
import requests

response = requests.post(
    "https://api.freddy.aitronos.com/v1/model/response",
    headers={"Authorization": f"Bearer {api_key}"},
    json={"model": "gpt-4.1", "stream": True, "inputs": [...]},
    stream=True
)

for line in response.iter_lines():
    if line:
        line_str = line.decode('utf-8')
        if line_str.startswith('data: '):
            data = json.loads(line_str[6:])
            print(data)
```