---
title: "read: document changes"
description: "two versions to every number that moved with its unit, every figure replaced"
section: reference
address: /reference/read/document_changes
contract: 0476e35e6e275db5
---
# read: document changes
two versions to every number that moved with its unit, every figure replaced
[figure: The caller sends DocumentChangesInput to /v1/read/document_changes. The platform returns a card whose body is WhatChanged.]
POST/v1/read/document_changes
What changed. The call needs the brand rung under a token with the read grant, and it is served by the platform.
The route takes [DocumentChangesInput](/concepts/documentchangesinput) and returns a card whose body is [WhatChanged](/concepts/whatchanged).
## Request body
The request body is [DocumentChangesInput](/concepts/documentchangesinput).
| field | type | required | note |
|---|---|---|---|
| `document` | `id` | yes | |
| `first` | `count` | yes | |
| `second` | `count` | yes | |
## Response
The route returns a card whose body is [WhatChanged](/concepts/whatchanged). Every card ends with a foot that states the basis of each number, the scope of the call, and the time when the facts were true.
## Headers
| header | required | meaning |
|---|---|---|
| `Scale-Scope` | yes | the scope the call runs in: tenant/, then /brand/, then /strategy/ |
| `Scale-As-True-On` | no | the date the facts must have been true on; defaults to now |
| `Scale-As-Known-On` | no | the date the facts must have been known on; defaults to now |
| `Scale-Key` | no | for a change, the key made from the input; a repeat under the same key returns the unit held and writes nothing |
A caller needs the brand rung and a token with the read grant. The platform serves this route.
## Example
The example sends the smallest body that DocumentChangesInput allows. The build validates it against the schema of DocumentChangesInput.
Example
```sh
curl -X POST https://api.scaleintelligence.co/v1/read/document_changes \
-H "Scale-Key: $SCALE_KEY" -H "Scale-Scope: tenant/" \
-H "content-type: application/json" \
-d '{ "document": "…", "first": 0, "second": 0 }'
```
```typescript
import { client } from "@scale/sdk";
const answer = await client.read.document_changes({
"document": "…",
"first": 0,
"second": 0
});
// answer.body is a WhatChanged. answer.foot holds the basis, the scope and the time.
```
```python
import requests
answer = requests.post("https://api.scaleintelligence.co/v1/read/document_changes",
headers={"Scale-Key": KEY, "Scale-Scope": "tenant/"},
json={
"document": "…",
"first": 0,
"second": 0
}).json()
```
```rust
let answer: Card = client.post("https://api.scaleintelligence.co/v1/read/document_changes")
.header("Scale-Key", key).header("Scale-Scope", "tenant/")
.json(&DocumentChangesInput { /* the fields of the page */ }).send().await?.json().await?;
```