# Compare Documents (Api-Version: 2)

**`POST /projects/compare/documents`** — requires `Api-Version: 2` header

Compares two or more project documents. Version 2 returns an extended response that includes separate comparison results for both `projects` and `presentations`.

***

## Request

### Headers

| Header        | Value | Required | Description                                                              |
| ------------- | ----- | -------- | ------------------------------------------------------------------------ |
| `Api-Version` | `2`   | Yes      | Enables V2 behaviour (extended response with projects and presentations) |

### Request Body

Either `documentId1` + `documentId2`, or `documentIds` (array of at least 2 IDs).

```json
{
  "documentId1": "f3b2a9c1e4d5678901234567",
  "documentId2": "a1b2c3d4e5f6789012345678"
}
```

```json
{
  "documentIds": [
    "f3b2a9c1e4d5678901234567",
    "a1b2c3d4e5f6789012345678"
  ]
}
```

| Field         | Type      | Required    | Description                                 |
| ------------- | --------- | ----------- | ------------------------------------------- |
| `documentId1` | String    | Conditional | First document ID (use with `documentId2`)  |
| `documentId2` | String    | Conditional | Second document ID (use with `documentId1`) |
| `documentIds` | String\[] | Conditional | Array of at least 2 document IDs            |

***

## Response

### Success Response

**Status:** `200 OK`

Returns an extended comparison result with separate sections for projects and presentations.

```json
{
  "projects": {
    "documents": {},
    "left": {},
    "right": {},
    "total": {}
  },
  "presentations": {
    "documents": {},
    "left": {},
    "right": {},
    "total": {}
  }
}
```

### Error Responses

| Status                      | Description                                                                |
| --------------------------- | -------------------------------------------------------------------------- |
| `422 Unprocessable Entity`  | Neither a valid document pair nor a valid `documentIds` array was provided |
| `500 Internal Server Error` | Unexpected server failure                                                  |


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://guardian.hedera.com/docs/develop/guardian/project-comparison/project-comparison-apis/compare-documents-v2.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.