# Start a planned test

`POST /hosting/sites/{id}/experiments/{exp}/start` · Rivier · hosting

Start a planned test; visitors see it from the next production release (which a person approves). A person only.

- Scope: hosting:write
- Graphql: Mutation.hostingExperimentStart
- Sdk: hosting.experiment.start
- Cli: hosting experiment start

## Parameters

- `id` (path, required), string
- `exp` (path, required), string

## Responses

- `200`: Success
- `400`: The request was malformed
- `401`: No valid credential
- `403`: The credential lacks the scope, origin or address
- `429`: Over the key's rate limit; see Retry-After

## Example

```sh
curl -X POST 'https://api.rivier.ai/hosting/sites/{id}/experiments/{exp}/start' \
  -H 'Authorization: Bearer $KEY'
```