> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cludo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Versions: v3 vs v4

> Compare Cludo API v3 and v4 endpoints, see which version supports each feature, and plan a migration from legacy v3 calls to the modern v4 API.

Not all Cludo APIs use the same version. This guide explains exactly which version to use for each feature.

***

## The short version

| Feature                                                    | Which Version?                        |
| ---------------------------------------------------------- | ------------------------------------- |
| **Search & Autocomplete**                                  | Use **v4** (v3 also works)            |
| **AI Chat & AI Summary**                                   | Use **v4** (only available in v4)     |
| **Push/manage documents**                                  | Use **v4** Index Management           |
| **Queue URLs for crawling**                                | Use **v4**                            |
| **Analytics tracking**                                     | Use **v3** (querylog, clicklog)       |
| **Search tools** (banners, rankings, quicklinks, synonyms) | **No version** - use `/api/...` paths |

***

## Search & Autocomplete

**Use v4 for new integrations.** Both v3 and v4 work and return compatible responses, but v4 is the current version.

```text theme={null}
POST /api/v4/{customerId}/{engineId}/search
GET  /api/v4/{customerId}/{engineId}/autocomplete
```

***

## AI Chat & AI Summary

**v4 only.** These features do not exist in v3.

```text theme={null}
POST /api/v4/{customerId}/{engineId}/search/answer      (AI Chat)
POST /api/v4/{customerId}/{engineId}/search/summarize   (AI Summary)
```

***

## Pushing documents (Index Management)

**Use v4.** The v4 Index Management API replaced v3 Content Management.

* Use `PUT` to replace/create documents
* Use `PATCH` to update specific fields (new in v4)
* Use `DELETE` to remove documents

```text theme={null}
PUT    /api/v4/{customerId}/index/{crawlerId}/documents
PATCH  /api/v4/{customerId}/index/{crawlerId}/documents
DELETE /api/v4/{customerId}/index/{crawlerId}/documents
```

***

## Queue URLs for crawling

**Use v4.** If you previously used v3 PushURLs, the v4 equivalent is:

```text theme={null}
POST /api/v4/{customerId}/crawler/{crawlerId}/paths
```

***

## Analytics tracking

**Use v3.** There is no v4 version of the tracking endpoints. Continue using the v3 paths:

```text theme={null}
POST /api/v3/{customerId}/{engineId}/search/pushstat/querylog   (track searches)
POST /api/v3/{customerId}/{engineId}/search/pushstat/clicklog   (track clicks)
```

***

## Search Tools (Banners, Rankings, Quicklinks, Synonyms)

**No version number.** These endpoints use unversioned `/api/...` paths. Do not add `/v3` or `/v4`:

```text theme={null}
/api/banners/...
/api/rankings/...
/api/quicklinks/...
/api/synonymsgroup/...
```

See [Search Tools](/api-reference/overview#search-tools) for the full API reference.

***

## Summary

* **New integrations**: Use v4 for everything except tracking (v3) and search tools (unversioned)
* **Existing v3 integrations**: Search and autocomplete continue to work on v3. Migrate content management to v4 Index Management when ready.
* **Tracking**: Always v3
* **Search tools**: Never add a version number