> ## 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.

# Evaluation

> Ship your document processing with Extend. Get started with our APIs, SDKs, and guides.

## Docs

- [Evaluation Overview](https://docs.extend.ai/2026-02-09/evaluation/overview.md): Evaluation sets measure the accuracy of an extractor, classifier, or splitter against reviewed ground truth. Create sets and run them via the SDK (evaluationSets, evaluationSetItems, evaluationSetRuns) or in Extend Studio.
- [Processors](https://docs.extend.ai/2026-02-09/evaluation/processors.md): A processor is a saved, versioned extractor, classifier, or splitter — the entity your runs are tracked against and the thing you iterate on, evaluate, and optimize.
- [Publishing Processors](https://docs.extend.ai/2026-02-09/evaluation/publishing-processors.md): Publish a new major or minor version of an extractor, classifier, or splitter.
- [Creating Evaluation Sets](https://docs.extend.ai/2026-02-09/evaluation/creating-evaluation-sets.md): Create an evaluation set, upload files, and add items with expected outputs using the SDK (Python, TypeScript, Java, Go) or Extend Studio. Covers evaluationSets.create, files.upload, and evaluationSetItems.create.
- [Running Evaluation Sets](https://docs.extend.ai/2026-02-09/evaluation/running-evaluation-sets.md): Start an evaluation set run against a processor version, poll it to completion, and read accuracy metrics using the SDK (Python, TypeScript, Java, Go) or Extend Studio. Covers evaluationSetRuns.create, evaluationSetRuns.retrieve, and evaluationSetItems.update.
- [Calculating Array Accuracy](https://docs.extend.ai/2026-02-09/evaluation/calculating-array-accuracy.md): How Extend calculates accuracy for array data