# Experiment commands: conclude, start

URL: /code/cli/experiment/verbs · Id: `page:code/cli/experiment/verbs`

> The Experiment Verbs conclude, start as CLI commands, with inputs, result, refusals and an example.

Reference for [Experiment](/business/nouns/experiment), one group of [Experiment commands](/code/cli/experiment).

### Experiment.conclude
Conclude ends an Experiment with a decision to ship, kill, or iterate, recorded as a Decision. [Verb page](/business/nouns/experiment/conclude?interface=cli).

```text
npx startup-builder do Experiment.conclude --json '<input>' [--try | --send | --do]
```

Emits [`Experiment.concluded`](/business/events/Experiment.concluded).

**Inputs**

| Input | Type | Required | Description |
| --- | --- | --- | --- |
| `experiment` | [Experiment](/business/nouns/experiment) | Yes | The running Experiment. |
| `decision` | `string` | Yes | One of `ship`, `kill`, `iterate`. |

**Returns**

| Output | Type | Required | Description |
| --- | --- | --- | --- |
| `decision` | [Decision](/business/nouns/decision) | Yes | The recorded Decision. |
| `experiment` | [Experiment](/business/nouns/experiment) | Yes | The Experiment, now concluded. |

**Refuses when**

| Check | Error | Fix | Then call |
| --- | --- | --- | --- |
| The input does not match the schema of the operation. | [`invalid-input`](/code/api/errors/invalid-input) | Read the schema of the operation, then send every required field with the right type. | None. |
| The key is valid, but its scopes do not allow this operation. | [`forbidden`](/code/api/errors/forbidden) | Use a key whose scopes cover the operation, or ask an owner of the namespace to grant them. | None. |
| The record is not in a state that allows this Verb, so the call is refused. | [`refused`](/code/api/errors/refused) | Read the record, run the Verb that moves it to an allowed state, then retry. | None. |

**Example**

```bash
npx startup-builder do Experiment.conclude --json '{"experiment":"experiment_IyIJJPngKt","decision":"ship"}'
```

### Experiment.start
Start opens an Experiment, splits traffic across its variants, and begins measuring its primary and guardrail Metrics. [Verb page](/business/nouns/experiment/start?interface=cli).

```text
npx startup-builder do Experiment.start --json '<input>' [--try | --send | --do]
```

Emits [`Experiment.started`](/business/events/Experiment.started).

**Inputs**

| Input | Type | Required | Description |
| --- | --- | --- | --- |
| `experiment` | [Experiment](/business/nouns/experiment) | Yes | The Experiment to open. |

**Returns**

| Output | Type | Required | Description |
| --- | --- | --- | --- |
| `experiment` | [Experiment](/business/nouns/experiment) | Yes | The running Experiment. |

**Refuses when**

| Check | Error | Fix | Then call |
| --- | --- | --- | --- |
| The input does not match the schema of the operation. | [`invalid-input`](/code/api/errors/invalid-input) | Read the schema of the operation, then send every required field with the right type. | None. |
| The key is valid, but its scopes do not allow this operation. | [`forbidden`](/code/api/errors/forbidden) | Use a key whose scopes cover the operation, or ask an owner of the namespace to grant them. | None. |
| The record is not in a state that allows this Verb, so the call is refused. | [`refused`](/code/api/errors/refused) | Read the record, run the Verb that moves it to an allowed state, then retry. | None. |

**Example**

```bash
npx startup-builder do Experiment.start --json '{"experiment":"experiment_IyIJJPngKt"}'
```