---
title: "Thread Truncation Controls"
url: "https://kongair.terwilligar.com/apis/openai-api-2-3-0/versions/ea92d048-c746-4ead-a6a8-da28d93137d1/schemas/TruncationObject"
---

> Full API specification: https://kongair.terwilligar.com/apis/openai-api-2-3-0/versions/ea92d048-c746-4ead-a6a8-da28d93137d1.md

# Thread Truncation Controls

Controls for how a thread will be truncated prior to the run. Use this to control the intial context window of the run.

## OpenAPI definition

```yaml
openapi: 3.0.0
info:
  title: OpenAI API
  version: 2.3.0
servers:
  - url: https://api.openai.com/v1
components:
  schemas:
    TruncationObject:
      type: object
      title: Thread Truncation Controls
      description: Controls for how a thread will be truncated prior to the run. Use
        this to control the intial context window of the run.
      properties:
        type:
          type: string
          description: The truncation strategy to use for the thread. The default is
            `auto`. If set to `last_messages`, the thread will be truncated to
            the n most recent messages in the thread. When set to `auto`,
            messages in the middle of the thread will be dropped to fit the
            context length of the model, `max_prompt_tokens`.
          enum:
            - auto
            - last_messages
        last_messages:
          type: integer
          description: The number of most recent messages from the thread when
            constructing the context for the run.
          minimum: 1
          nullable: true
      required:
        - type
```