> ## Documentation Index
> Fetch the complete documentation index at: https://docs.leadterra.co/llms.txt
> Use this file to discover all available pages before exploring further.

# POST /v1/campaigns/:id/pause — Pause a Running Campaign

> POST /v1/campaigns/:id/pause — Pauses a running campaign immediately. Queued messages not yet sent are held. Resume by calling the start endpoint again.

Use this endpoint to immediately pause a running campaign. When a campaign is paused, Leadterra stops scheduling new outbound messages, but any emails already in transit are still delivered. Messages that were queued but not yet sent are held and will resume from the same position when you call the [start endpoint](/api-reference/campaigns-start) again. Pausing is useful when you need to update copy, investigate deliverability issues, or temporarily halt outreach.

```bash theme={null}
POST /v1/campaigns/:id/pause
```

## Authorization

All requests must include a Bearer token in the `Authorization` header. You can find your API key in the Leadterra dashboard under **Settings → API Keys**.

## Path Parameters

<ParamField path="id" type="string" required>
  The unique ID of the campaign you want to pause. You receive this ID when you [create a campaign](/api-reference/campaigns-create). Example: `camp_123`.
</ParamField>

## Request Body

This endpoint accepts no request body.

## Example Request

```bash theme={null}
curl --request POST \
  --url https://app.leadterra.co/v1/campaigns/camp_123/pause \
  --header "Authorization: Bearer sk_live_YOUR_KEY" \
  --header "Content-Type: application/json"
```

## Response Fields

<ResponseField name="id" type="string">
  The campaign ID that was paused.
</ResponseField>

<ResponseField name="status" type="string">
  Updated campaign status. Returns `paused` on success.
</ResponseField>

<ResponseField name="pausedAt" type="string">
  ISO 8601 timestamp of when the campaign transitioned to `paused`.
</ResponseField>

## Example Response

```json theme={null}
{
  "id": "camp_123",
  "status": "paused",
  "pausedAt": "2025-01-15T14:22:00Z"
}
```

## Notes

* Calling this endpoint on a campaign that is already `paused` or in `draft` status is a no-op — the response returns the current state without error.
* Emails that were already in transit before the pause signal was received will still be delivered to recipients.
* To resume sending, call the [Start Campaign](/api-reference/campaigns-start) endpoint with the same campaign ID.

## Error Codes

| HTTP Status        | Code                    | Meaning                                                                  |
| ------------------ | ----------------------- | ------------------------------------------------------------------------ |
| `400 Bad Request`  | `invalid_request`       | The request was malformed or contained unexpected parameters.            |
| `401 Unauthorized` | `authentication_failed` | The `Authorization` header is missing, malformed, or the key is invalid. |
| `404 Not Found`    | `campaign_not_found`    | No campaign with the given `id` exists in your workspace.                |