---
title: "/responses/compact"
url: "/docs/response_api_compact"
canonical_url: "https://docs.litellm.ai/docs/response_api_compact"
type: "docs"
last_updated: "2026-10-10"
summary: "Compress conversation history using OpenAI's /responses/compact endpoint."
related:
  - "/docs/prompt_management"
  - "/docs/search/"
---
# /responses/compact

> Index of all LiteLLM docs: https://docs.litellm.ai/llms.txt


Compress conversation history using OpenAI's `/responses/compact` endpoint.

| Feature | Supported |
|---------|-----------|
| Supported LiteLLM Versions | 1.72.0+ |
| Supported Providers | `openai` |

## Usage

### LiteLLM Python SDK

```python showLineNumbers title="Compact Response"
import litellm

response = litellm.compact_responses(
    model="openai/gpt-5.6-terra",
    input=[{"role": "user", "content": "Hello, how are you?"}],
    instructions="Be helpful",
    previous_response_id="resp_abc123"  # optional
)

print(response.id)
print(response.object)  # "response.compaction"
print(response.output)
```

### LiteLLM Proxy

**Curl**

```bash showLineNumbers title="Compact Request"
curl http://localhost:4000/v1/responses/compact \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $LITELLM_API_KEY" \
  -d '{
    "model": "openai/gpt-5.6-terra",
    "input": [{"role": "user", "content": "Hello"}],
    "instructions": "Be helpful"
  }'
```

**OpenAI Python SDK**

```python showLineNumbers title="Compact with OpenAI SDK"
import httpx

response = httpx.post(
    "http://localhost:4000/v1/responses/compact",
    headers={"Authorization": "Bearer sk-<your-litellm-api-key>"},
    json={
        "model": "openai/gpt-5.6-terra",
        "input": [{"role": "user", "content": "Hello"}],
        "instructions": "Be helpful"
    }
)

print(response.json())
```

## Request Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `model` | string | Yes | Model to use for compaction |
| `input` | string or array | Yes | Input messages to compact |
| `instructions` | string | No | System instructions |
| `previous_response_id` | string | No | ID of previous response to continue from |

## Response Format

```json
{
  "id": "resp_abc123",
  "object": "response.compaction",
  "created_at": 1734366691,
  "output": [
    {
      "type": "message",
      "role": "assistant",
      "content": [...]
    },
    {
      "type": "compaction",
      "encrypted_content": "..."
    }
  ],
  "usage": {
    "input_tokens": 100,
    "output_tokens": 50,
    "total_tokens": 150
  }
}
```

## Related pages

- [Prompt Management with Responses API](https://docs.litellm.ai/docs/prompt_management.md)
- [Overview](https://docs.litellm.ai/docs/search/index.md)