> 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.

# Get Evaluation Set

GET https://api.extend.ai/evaluation_sets/{id}

Retrieve a specific evaluation set by ID. This returns an evaluation set object, but does not include the items in the evaluation set. You can use the [List Evaluation Set Items](https://docs.extend.ai/2025-04-21/developers/api-reference/evaluation-set-endpoints/list-evaluation-set-items) endpoint to get the items in an evaluation set.


Reference: https://docs.extend.ai/2025-04-21/developers/api-reference/evaluation-set-endpoints/get-evaluation-set

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Request

### Path parameters

- `id` (string, required) — The ID of the evaluation set to retrieve. Example: `"ev_2LcgeY_mp2T5yPaEuq5Lw"`

### Headers

- `x-extend-api-version` ("2025-04-21", optional, default: 2025-04-21) — API version to use for the request. If you do not specify a version, you will either receive a `400 Bad Request` or be set to a previous legacy version. See [API Versioning](https://docs.extend.ai/2025-04-21/developers/api-versioning) for more details.
- `x-extend-workspace-id` (string, optional) — The workspace ID to target. **Required** when using an organization-scoped API key; optional for workspace-scoped keys (the key is already tied to a workspace). See [Authentication](https://docs.extend.ai/2025-04-21/developers/authentication) for details on API key scopes.

## Response

### 200

Successfully retrieved evaluation set

- `success` (boolean, required)
- `evaluationSet` (EvaluationSet, required) — The EvaluationSet object represents an evaluation set in Extend. Evaluation sets are collections of files and expected outputs that are used to evaluate the performance of a given processor in Extend.

## Errors

### 400 Bad Request Error

Bad Request

- `success` (boolean, optional)
- `error` (string, optional) — Error message

### 401 Unauthorized Error

Unauthorized

- `success` (boolean, optional)
- `error` (string, optional) — Error message

### 404 Not Found Error

Evaluation set not found

- `success` (boolean, optional)
- `error` (string, optional) — Error message

## Types

### EvaluationSet

The EvaluationSet object represents an evaluation set in Extend. Evaluation sets are collections of files and expected outputs that are used to evaluate the performance of a given processor in Extend.

- `object` (string, required) — The type of response. In this case, it will always be `"evaluation_set"`.
- `id` (string, required) — The ID of the evaluation set. Example: `"ev_2LcgeY_mp2T5yPaEuq5Lw"`
- `name` (string, required) — The name of the evaluation set. Example: `"Invoice Processing Test Set"`
- `description` (string, required) — A description of the evaluation set. Example: `"Q4 2023 vendor invoices for accuracy testing"`
- `processorId` (string, required) — The ID of the processor associated with this evaluation set. Example: `"dp_Xj8mK2pL9nR4vT7qY5wZ"`
- `createdAt` (string, required) — The time (in UTC) at which the evaluation set was created. Will follow the RFC 3339 format. Example: `"2024-03-21T15:30:00Z"`
- `updatedAt` (string, required) — The time (in UTC) at which the evaluation set was last updated. Will follow the RFC 3339 format. Example: `"2024-03-21T16:45:00Z"`

## Examples

**Response**

```json
{
  "success": true,
  "evaluationSet": {
    "object": "evaluation_set",
    "id": "ev_2LcgeY_mp2T5yPaEuq5Lw",
    "name": "Invoice Processing Test Set",
    "description": "Q4 2023 vendor invoices for accuracy testing",
    "processorId": "dp_Xj8mK2pL9nR4vT7qY5wZ",
    "createdAt": "2024-03-21T15:30:00Z",
    "updatedAt": "2024-03-21T16:45:00Z"
  }
}
```