POST/campaigns/:campaignId/start

Start outreach for a ready campaign, or resume a paused one. Same behavior as the dashboard Start / Resume controls.

0 credits. Kicks off real LinkedIn outbound — confirm before calling. The campaign must already have an agent assigned (assignedTemplateId). Create agents and connect LinkedIn in the dashboard.

Current status	Behavior
`READY_TO_SEND`	Start → `CAMPAIGN_IN_PROGRESS` (`action: started`)
`FAILED` with leads	Start → `CAMPAIGN_IN_PROGRESS` (`action: started`)
`CAMPAIGN_PAUSED`	Resume → `CAMPAIGN_IN_PROGRESS` (`action: resumed`)
`CAMPAIGN_IN_PROGRESS`	No-op success (`action: noop`)
`COMPLETED` / `DONE`	409 `conflict` (API does not restart completed campaigns)
`FAILED` with no leads	409 `conflict` — add leads first
Other (e.g. still preparing)	409 `conflict`

Typical flow

Dashboard: create campaign, assign an agent, connect LinkedIn
API: add leads (POST …/leads) if needed
POST …/start → outreach runs
POST …/pause / POST …/start again to pause / resume

POST /campaigns/search_abc/start
X-API-Key: sk_live_...
Content-Type: application/json

{}

Body must be empty or {}. Any other fields → 400 validation_error.

{
  "campaignId": "search_abc",
  "action": "started",
  "status": "CAMPAIGN_IN_PROGRESS",
  "campaign": {
    "id": "search_abc",
    "name": "Q3 outbound",
    "status": "CAMPAIGN_IN_PROGRESS",
    "totalLeads": 120,
    "assignedTemplateId": "tpl_...",
    "stats": {
      "connectionRequestsSent": 80,
      "connectionRequestsAccepted": 20,
      "acceptanceRate": 25.0,
      "messagesSent": 40,
      "repliesReceived": 8,
      "replyRate": 20.0
    }
  }
}

Field	Values
`campaignId`	Same as path
`action`	`started` \| `resumed` \| `noop`
`status`	Post-call status (usually `CAMPAIGN_IN_PROGRESS`)
`campaign`	Same shape as GET /campaigns/:id

Error code	When
`validation_error`	Body has extra fields, or no agent assigned
`not_found`	Unknown campaign / template
`account_disconnected`	Agent's LinkedIn account not connected
`plan_required`	Plan inactive (usually blocked at auth)
`conflict`	Wrong status / no leads on `FAILED` / completed
`rate_limited`	Over the start/pause limit (30 / minute)
`upstream_unavailable`	Temporary failure while resuming — retry

MCP: start_campaign (campaignId only) — confirm with the user before calling.