---
title: "act: weigh"
description: "a hypothesis, and a fact or a test's reading to the hypothesis with the evidence attached and its standing recomputed against its bar"
section: reference
address: /reference/act/weigh
contract: 0476e35e6e275db5
---
# act: weigh
a hypothesis, and a fact or a test's reading to the hypothesis with the evidence attached and its standing recomputed against its bar
[figure: The caller sends WeighInput to /v1/act/weigh. The platform returns a card whose body is Hypothesis.]
POST/v1/act/weigh
Weigh a claim. The call needs the strategy rung under a token with the act grant, and it is served by either, by the size bound.
The route takes [WeighInput](/concepts/weighinput) and returns a card whose body is [Hypothesis](/concepts/hypothesis).
## Request body
The request body is [WeighInput](/concepts/weighinput).
| field | type | required | note |
|---|---|---|---|
| `hypothesis` | `id` | yes | |
| `for` | [EvidenceRef](/concepts/evidenceref) | no | |
| `against` | [EvidenceRef](/concepts/evidenceref) | no | |
## Response
The route returns a card whose body is [Hypothesis](/concepts/hypothesis). 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 strategy rung and a token with the act grant. The platform or the desktop app serves this route.
## Example
The example sends the smallest body that WeighInput allows. The build validates it against the schema of WeighInput.
Example
```sh
curl -X POST https://api.scaleintelligence.co/v1/act/weigh \
-H "Scale-Key: $SCALE_KEY" -H "Scale-Scope: tenant/" \
-H "content-type: application/json" \
-d '{ "hypothesis": "…" }'
```
```typescript
import { client } from "@scale/sdk";
const answer = await client.act.weigh({
"hypothesis": "…"
});
// answer.body is a Hypothesis. answer.foot holds the basis, the scope and the time.
```
```python
import requests
answer = requests.post("https://api.scaleintelligence.co/v1/act/weigh",
headers={"Scale-Key": KEY, "Scale-Scope": "tenant/"},
json={
"hypothesis": "…"
}).json()
```
```rust
let answer: Card = client.post("https://api.scaleintelligence.co/v1/act/weigh")
.header("Scale-Key", key).header("Scale-Scope", "tenant/")
.json(&WeighInput { /* the fields of the page */ }).send().await?.json().await?;
```