What this helps you do
Flow is the Hub's door for content produced outside it: a publishing system, a report generator, a notice feed. A registered producer signs each item with its own secret and posts it to the ingest endpoint. The item lands in your Hub's review queue exactly as it would go out, with its text, links and any images. Approve or reject it, then Publish: that one human action turns it into a real Blast, with the Blasts fanout and the email leg. Ingest can never send on its own.
When to use it
Use Flow when the words are written by a system rather than a person: a generated digest, a scheduled report, an automated notice. If a person is writing the message, Send and Campaigns are the right tools.
How to do it
- Ask BlastsHub staff to register a producer for your organization. Producer credentials are issued by staff today, not self-serve; the signing secret is shown exactly once at issue time.
- Your producer signs each request (sha256 HMAC over a timestamp and the raw body, with a five-minute window) and posts the item.
- Open Review queue in your Hub (it appears for owners and administrators once a producer is registered). Each item shows a preview identical to the send and the audience it goes to.
- Approve or reject. Approval alone sends nothing.
- Click Publish on an approved item. The Hub reports how many Blasts and emails went out and how many attachments were uploaded.
Example
A publisher's puzzle system files tomorrow's puzzle with an image at 5:05. The editor opens the Review queue, sees the exact rendering, and publishes at 5:20. Readers on Blasts receive it with the image attached; readers who receive by email get the same rendering in their inbox.
Good to know
- Only owners and admins see the review queue and can publish.
- Every item keeps its status and reason: review, approved, rejected, published, or publish failed.
- Producer secrets are stored encrypted at rest and can be disabled by staff at any time.
- Published Flow items are normal Blasts: they cost credits and take the email leg like any other send.