Adds a Postscript subscriber to your shop and sends a reply based on which Keyword you specify in the request.

To find available keywords or inspect keyword replies, use Get Keywords endpoint.



  • Adding the field shopify_customer_id or email to the metadata object will help Postscript identify which customer belongs to the phone number you are sending.

  • The field metadata.tags will be stored on the subscriber, so those subscribers can later be filtered into segments by these tags.

  • You must pass either a keyword_id or keyword body param when adding a subscriber. You do not need to pass both. Which one you choose is up to you.

  • In the response, is_pending refers to the state of the subscriber that was added. Every subscriber added via our API requires a confirmation to opt-in for compliance reasons (see below section). If they have not confirmed yet, they will be in the pending state. Once confirmed, they will no longer be pending.


Text Messaging Compliance

All subscribers added using this endpoint will be required to confirm they have opted in to receive recurring automated messages. If a subscriber does not confirm, then they are not added to a merchant's subscriber list.

For more information about compliance, see our guide here.