Sync existing customers

Import signups, trials and customers into Leads and exclude them from cold outreach.

Requires the leads:write scope.

Response. { "ok": true, "leads": 1, "stage": "customer" }. A stale sourceUpdatedAt returns ignored: true and the retained relationship stage.

leads counts matched or created company records. A personal email or LinkedIn profile can return zero company records while still being excluded. Repeat the same source and externalId to update the relationship without duplicating the company. Outreach history is preserved. If several customer records match a company, a paying customer takes precedence over a trial, signup or former customer.

Known emails, company domains and LinkedIn profiles enter the enforced cold-outreach exclusions. Queued emails and open cold-outreach approval cards attached to matched leads or contacts are cancelled. Send gates recheck exclusions before sending; delivered messages cannot be recalled. Known contact profiles saved later are added to the exclusions too. An email alone cannot identify an unknown LinkedIn recipient.

Cancellation uses former_customer and keeps the exclusion. Omitting a customer from a later import does not unblock them. Customer-sync blocks cannot be removed through the blocklist endpoint.

A 400 identifies an invalid payload. A 401 means the token is missing or invalid; 403 means it lacks leads:write. Keep tokens server-side, verify signatures on your source provider's webhook handler, and retry network failures or 5xx responses with backoff. Read the current source record and serialize updates per customer ID so a delayed event cannot overwrite newer state. Check a synced identifier through the block list. Confirm a real source change appears there before treating ongoing sync as connected.