The campaign's leads with their per-step state

Lists the contacts enrolled in the campaign with their progress through the sequence. id is the campaign-membership row and contactId is the underlying contact, so you can cross-reference the contacts API. status is the state the app shows for the lead (it reads stopped or completed once the campaign itself stops), sentSteps/totalSteps show progress, and firstSentBy names the account and channel that first reached the lead. Only the token owner's own campaigns resolve: a campaign delegated to you, one shared by your team's visibility settings, and a deleted one all answer 404. Rate limit: 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.
• 422 VALIDATION_FAILED — A query parameter is out of range, or campaignId is not a 24-character hex id.
• 429 RATE_LIMITED — More than 30 campaign requests in a minute, or 1,000 in a day, for this token owner (the bucket is shared by every /business/campaigns, /business/scheduled-sends, /business/campaign-templates and /business/knowledge-hubs call).
• 500 UNEXPECTED_ERROR — An unhandled failure; the detail stays in our logs and is never returned.

Requires one of the following token scopes: campaigns.