Stop an active campaign (approve re-activates it)

Stops the campaign: sending halts immediately and its open task mirrors are cleared, while each contact keeps its own state so POST /business/campaigns/{campaignId}/approve resumes the same campaign rather than re-initializing it. Stopping a draft is allowed and simply parks it in stopped. Only the token owner's own campaigns can be stopped: a campaign delegated to you, one shared by your team's visibility settings, and a deleted one all answer 404. Rate limit: this endpoint and DELETE /business/campaigns/{campaignId} share a tighter cap of 10 requests/minute and 100/day, applied inside the shared campaigns bucket of 30 requests/minute and 1,000/day per token owner (shared by every campaign, scheduled-send, campaign-template and knowledge-hub endpoint).

Errors:

• 404 CAMPAIGN_NOT_FOUND — No campaign with this id exists, it belongs to another account (including a campaign delegated to you or shared by your team's visibility settings), or it has been deleted.
• 409 CAMPAIGN_BUSY — Another approve or stop is holding this campaign's activation lock. Retry in a few seconds.
• 422 VALIDATION_FAILED — campaignId is not a 24-character hex id.
• 429 RATE_LIMITED — Either this endpoint's own cap (10 requests/minute, 100/day) or the shared campaigns bucket (30/minute, 1,000/day for this token owner, shared by every /business/campaigns, /business/scheduled-sends, /business/campaign-templates and /business/knowledge-hubs call) was exceeded. The RateLimit-* headers on the response describe the shared bucket, so a refusal from this endpoint's own cap can still report requests remaining and carries no Retry-After.
• 500 UNEXPECTED_ERROR — An unhandled failure; the detail stays in our logs and is never returned.

Requires one of the following token scopes: campaigns.