Our gateway compared with SMS Flow

The pricing model

SMS Flow presents itself as a service without a subscription. It nonetheless charges 0.005 EUR per message sent and 0.003 EUR per message received and forwarded. Auto-responder actions are free and the number of devices is not capped.

So the claim of no subscriptions, no limits is accurate on the first half and misleading on the second: every message, inbound as well as outbound, has a price. The more you succeed, the more you pay.

With us, the marginal cost of a message is whatever your carrier plan charges, and nothing else.

What SMS Flow does very well

• A clean, consistent REST API, with a single authentication header and a single error envelope.
• A documented error table that spells out the business rules, not only the codes.
• A complete set of endpoints, with cURL, JavaScript and PHP examples and a copy button.
• An explicit campaign state machine whose status can never be edited by hand.
• A settings page structured into four readable blocks.
• A journal of received and forwarded messages that records the destination, the method and the forwarding status.
• A live character counter on the sending screen.

We keep all seven ideas and push them further: a machine-readable error code and a traceable request id, paused and cancelled campaign states on top of the existing ones, manual replay of a failed webhook, and a counter of segments rather than characters.

The limits

• Logs are stored in their cloud: no data sovereignty.
• The message is capped at 500 characters.
• Contacts are not paginated, pagination being announced for a future version.
• There is no two-way conversation interface.
• Settings have to be synchronised to the device manually.
• The device id is mandatory on every send: no automatic routing.

With us the message is not capped, every collection is cursor-paginated, settings are pushed to devices automatically, and the device id is optional because load balancing takes care of it.