---
title: "Send or schedule a campaign"
method: POST
path: "/api/v1/campaigns/{id}/send"
tags: ["Campaigns"]
---

# Send or schedule a campaign

`POST /api/v1/campaigns/{id}/send`

## Request

- Base URL: `https://api.sendly.now`
- URL: `https://api.sendly.now/api/v1/campaigns/{id}/send`
- Auth: one of:
  - HTTP bearer
  - API key in cookie `better-auth.session_token`
  - OAuth 2 (authorization code, authorization URL `https://app.sendly.now/api/auth/oauth2/authorize`, token URL `https://app.sendly.now/api/auth/oauth2/token`, scopes: `campaigns:send`)

Start sending immediately, or park the campaign in `SCHEDULED` by passing `scheduled_for` (which must be in the future). The request body may be omitted entirely to send now.

**Send an `Idempotency-Key`.** This is the operation that cannot be undone: a retry without one starts a second fan-out over the same audience. The key is scoped to this campaign, so the same key on a different campaign is a `422 idempotency_key_reused` rather than a replay of the first campaign's response.

Answers 400 when the campaign is not `DRAFT`/`SCHEDULED` or has no recipients, and 403 when the send would exceed the project's billing limit.

Requires the `campaigns:send` scope — Send or schedule your campaigns to their audience.

## Path parameters

- `id` string, uuid, required: Resource id.

## Headers

- `Idempotency-Key` string: Replay-safety key (24h TTL). Reuse it only to retry the identical request.

## Request body

- CampaignV1Send: Body for POST /api/v1/campaigns/{id}/send.
  - `scheduled_for` string, date-time: RFC 3339 timestamp, strictly in the future. A numeric UTC offset (`+02:00`) is accepted as well as `Z`. Omit to start sending immediately.

## Response `200`

The campaign, now `SENDING` or `SCHEDULED`

- CampaignV1: A campaign as exposed on the v1 API.
  - `audience_type` 'ALL' | 'FILTERED' | 'SEGMENT' | 'LIST', required
  - `created_at` string, date-time, required
  - `id` string, uuid, required
  - `list_id` string, uuid, nullable, required
  - `name` string, required
  - `scheduled_at` string, date-time, nullable, required
  - `sent_at` string, date-time, nullable, required
  - `stats` object, required
    - `bounced` integer, required
    - `clicked` integer, required
    - `delivered` integer, required
    - `opened` integer, required
    - `sent` integer, required
    - `total_recipients` integer, required
  - `status` 'DRAFT' | 'SCHEDULED' | 'SENDING' | 'PAUSED' | 'SENT' | 'CANCELLED', required
  - `subject` string, required
  - `topic_id` string, uuid, nullable, required

## Other responses

- `400`: `validation_error` — the campaign has already been sent or is sending, has no recipients, or `scheduled_for` is not in the future.
- `401`: `invalid_api_key` or `invalid_session` — missing or invalid credentials.
- `403`: `scope_missing`, `project_access_denied`, or `project_disabled`.
- `404`: `resource_not_found` — no campaign with this id belongs to the authenticated project.
- `409`: `conflict` — a request with this `Idempotency-Key` is still in flight. Retry shortly.
- `422`: `validation_error` — the request did not match the schema; or `idempotency_key_reused` — this `Idempotency-Key` was already spent on a request with a different body. A key names ONE request, so it is never silently served another one's result: send a new key.
- `429`: `rate_limited` — see `Retry-After` and the `RateLimit` headers.
- `500`: `internal_error`.

---

[API](https://skmtc.dev/sendly/apis/sendly-api.md) · [All operations](https://skmtc.dev/sendly/apis/sendly-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sendly/apis/sendly-api/revisions/ce7cfb7f7c7e?raw)