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Automation

API Flow

An API flow is PostPal's automated sending engine: you submit recipients programmatically through the API, PostPal collects them and forms a batch in a recurring weekly trigger window, then sends it as a postcard mailing. Billing is based on the batch size that is actually sent. Every flow needs a linked postcard design.

An API flow is PostPal's automated sending engine for recipients submitted programmatically. Instead of sending an existing segment, a flow continuously receives individual entries through the PostPal API and groups them into recurring mailings.

How a flow works:

  • You submit recipients through the API; they are collected as entries in the flow (states: pending, batched, skipped, failed).
  • In a weekly trigger window, PostPal forms a batch from due entries and creates a postcard mailing.
  • Billing is based on the actual batch size.

A flow is either active or paused and needs a linked postcard design. If credit is not sufficient for a batch, the flow remains configured and open entries are retried during the next run.

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Frequently asked questions

How is an API flow different from a normal campaign?
A campaign targets an existing segment. A PostPal API flow receives individual recipients continuously through the API and automatically groups them into recurring mailings, which is useful for event-based postcards.
How is an API flow billed?
PostPal bills an API flow by the actual batch size, not by a minimum quantity. The trigger threshold only controls when a weekly batch is formed.
What happens if my credit is not enough for a batch?
The flow remains configured. Open entries are retried in the next weekly run, and you are notified about the missing credit.
Do I need a design for an API flow?
Yes. Every API flow needs a linked postcard design before it can create mailings.