> This page is for version v2025-04-21.
> For other versions, use one of these documentation indexes:
> - v2026-02-09 (default): https://docs.extend.ai/2026-02-09/llms.txt
> - v2025-04-21: https://docs.extend.ai/2025-04-21/llms.txt
> - v2024-12-23: https://docs.extend.ai/2024-12-23/llms.txt

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.extend.ai/llms.txt
> Use this file to discover all available pages before exploring further.
>
> ## API version
> The current API version is `2026-02-09`, served at the site root (no version prefix in URLs).
> If this page URL contains `/2025-04-21/` or `/2024-12-23/`, you are reading an older API version.
> Prefer the current docs at https://docs.extend.ai/llms.txt unless the user explicitly needs that older version.
> Do not treat older-version pages as the source of truth for new integrations.

# Classifier output types

> Understanding the output type for classifiers.

Classifer outputs follow standardized formats. Understanding this format is essential when working with evaluation sets, webhooks, and API responses.

## Classification Output Type

### Type Definition

```typescript
type ClassificationOutput = {
  id: string;
  type: string;
};
```

### Example

```json
{
  "id": "classification_123",
  "type": "INVOICE"
}
```

## Shared Types

Certain types are shared across different processor outputs. These provide additional context and information about the processor's decisions.

### Type Definition

```typescript
type Insight = {
  type: "reasoning" | "issue" | "review_summary";
  content: string;
};
```

### Example

```json
{
  "insights": [
    {
      "type": "reasoning",
      "content": "This was classified as an invoice because it contains standard invoice elements including an invoice number, billing details, and itemized charges."
    }
  ]
}
```

Insights can appear in both Extraction and Classification outputs to provide transparency into the model's decision-making process. They are particularly useful when debugging or validating processor results.