Campaigns

A campaign bundles a schedule, settings, an email sequence, the sending accounts, and its leads. The API is task-shaped: you create a fully-configured campaign in one call rather than stitching together six.

Scopes

Action	Scope
Read campaigns and status	`campaigns:read`
Create / update / delete config	`campaigns:write`
Start / pause / resume sending	`campaigns:lifecycle`

Lifecycle is deliberately a separate scope from campaigns:write: starting a campaign spends send quota and sender reputation. A key with only campaigns:write can build and edit a campaign but cannot start sending. Creating with launch: true therefore needs both scopes.

Create a campaign

A campaign created through the API sends from all connected mailboxes of your workspace (“use all accounts” mode). accounts attaches mailboxes to the campaign, but it does not limit which mailboxes send.

One call configures everything. The configuration - campaign, schedule, settings, sending accounts, and sequence - is all-or-nothing: if any part fails validation (for example an SMTP account that isn’t yours), nothing is created. accounts must be your workspace’s own accounts. leads are best-effort and summarized in the response. If launch: true is set and the campaign can’t start, the call still returns 201 - the campaign is created as a draft, with launched: false and a launchError explaining why (start it later with POST /v1/campaigns/{id}/start). Because the response is a success, a retry with the same Idempotency-Key replays it instead of creating a second draft.

curl -X POST https://api.mailbeast.ai/v1/campaigns \
  -H "Authorization: Bearer $MAILBEAST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Q4 Product Launch Outreach",
    "schedule": {
      "timezone": "America/New_York",
      "sendingDays": [1, 2, 3, 4, 5],
      "sendingMinutesStart": 540,
      "sendingMinutesEnd": 1020,
      "dailyLimit": 50
    },
    "settings": { "trackOpens": true, "trackClicks": true, "stopOnReply": true },
    "sequence": [
      { "subject": "Quick question about {{companyName}}", "body": "<p>Hi {{firstName}}, …</p>" },
      { "subject": "Following up", "body": "<p>Just circling back.</p>", "delayDays": 3 }
    ],
    "accounts": ["123e4567-e89b-12d3-a456-426614174000"],
    "leads": ["[email protected]", "[email protected]"],
    "launch": false
  }'

sendingMinutesStart / sendingMinutesEnd are minutes from midnight in the campaign timezone - 540 = 09:00, 1020 = 17:00. Step delays are counted from the previous step; the first step sends immediately when a lead enters.

The response returns the created campaign plus a lead-ingest summary:

Response

{
  "campaign": {
    "id": "333e9ef7-734d-40b2-9e3f-cbce63411b69",
    "name": "Q4 Product Launch Outreach",
    "status": "draft",
    "schedule": { "timezone": "America/New_York", "dailyLimit": 50, "…": "…" },
    "settings": { "trackOpens": true, "trackClicks": true, "stopOnReply": true, "sendAsTextOnly": false },
    "metrics": { "leadsCount": 2, "sent": 0, "opens": 0, "clicks": 0, "replies": 0 },
    "sequence": [ { "subject": "Quick question about {{companyName}}", "body": "<p>Hi {{firstName}}, …</p>", "delayDays": 0, "delayHours": 0 } ],
    "accounts": ["123e4567-e89b-12d3-a456-426614174000"]
  },
  "leads": { "submitted": 2, "created": 2, "duplicates": 0, "invalid": 0 },
  "launched": false
}

Launch and control sending

Drive the send lifecycle through explicit routes - /start, /pause, or /resume. To end a campaign, pause it (or delete it); completion otherwise happens automatically when the end date passes or every lead has been sent.

curl -X POST https://api.mailbeast.ai/v1/campaigns/{id}/start \
  -H "Authorization: Bearer $MAILBEAST_API_KEY"

You can also launch at creation time by passing "launch": true in the create body (requires campaigns:lifecycle).

A campaign must have at least one lead and a sequence to start. A launch attempt without them is rejected 400 on POST /start; on create-with-launch the campaign is still created and returned as a draft (201, launched: false, with a launchError).

Send a test email

Before you launch, send yourself a rendered preview of one step variant, from a real mailbox, exactly as a lead would receive it.

curl -X POST https://api.mailbeast.ai/v1/campaigns/{id}/test-email \
  -H "Authorization: Bearer $MAILBEAST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "variantId": "550e8400-e29b-41d4-a716-446655440000",
    "accountId": "3f1c2b7e-9a4d-4e18-b2c1-6d8f5a0e7c93",
    "recipient": "[email protected]",
    "personalization": "dummy"
  }'

Response

{ "sent": true, "messageId": "<[email protected]>" }

personalization decides where merge variables come from. dummy fills them with placeholders. lead uses a real lead, which you name with leadId. There is no fallback: asking for lead without a leadId is rejected, so a test can never quietly leak the wrong person’s data into an email.

The content is the campaign’s own: you cannot supply a body here, so this is not a way to send arbitrary mail.A test goes out from a real mailbox and counts toward that mailbox’s daily limit, but not toward your monthly email quota. It is capped at 12 tests per day per workspace (429 beyond that).The recipient must not be blocked in your workspace. A test carries your campaign content, so the same do-not-email rules apply to it as to a real send: it is refused for anyone on your blacklist, by address or by domain. That list is your own instruction not to contact someone, and a test is not an exception to it.

A 400 means something about the request needs changing – the mailbox rejected the recipient, for example – and the message says what. If the send fails on our side instead, you get a 503: the request was fine, it costs you no quota, and retrying shortly is the right move. Distinguishing the two matters if you retry automatically: a 400 is worth giving up on, a 503 is not.

Check status

A lightweight poll of live send-state, the schedule window, and headline metrics:

curl https://api.mailbeast.ai/v1/campaigns/{id}/status \
  -H "Authorization: Bearer $MAILBEAST_API_KEY"

Response

{
  "id": "333e9ef7-734d-40b2-9e3f-cbce63411b69",
  "status": "active",
  "isWithinSchedule": true,
  "nextScheduleOpensAt": null,
  "metrics": { "leadsCount": 2, "sent": 2, "opens": 1, "clicks": 0, "replies": 0 }
}

Update

PATCH touches only the sections you supply. Supplying accounts or sequence replaces that section entirely (the sequence is replaced in place - you always end up with exactly the steps you sent). A supplied sequence must have at least one step - an empty array is rejected (400); omit the field to leave the sequence unchanged.

curl -X PATCH https://api.mailbeast.ai/v1/campaigns/{id} \
  -H "Authorization: Bearer $MAILBEAST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "schedule": { "dailyLimit": 100 } }'

Unlike create, PATCH applies each supplied section independently - it is not a single cross-section transaction, so a later section failing does not roll back an earlier one. Send one section at a time if you need to isolate failures. The sequence of a campaign that is actively sending cannot be changed; pause it first. accounts can be updated live, but it does not limit which mailboxes send - the campaign sends from all connected mailboxes of the workspace.

Get started

Resources

Scopes

Create a campaign

Launch and control sending

Send a test email

Tags

Check status

Update

​Scopes

​Create a campaign

​Launch and control sending

​Send a test email

​Tags

​Check status

​Update

Scopes

Create a campaign

Launch and control sending

Send a test email

Tags

Check status

Update