Guides
Practical guides to sending SMS
Parts, encodings, senders and retries: the rules that decide what gets delivered and what you pay, explained once and for all.
What an SMS "part" is
How one message becomes 1, 2 or 4 billed SMS: GSM-7 encoding, the 160-character boundary and the exact moment the price doubles.
Read the guideAlphanumeric senders in Italy
Your brand name in place of the number: the 11-character rules, the approval flow, the channel's real limits and when the system sender is the better choice.
Read the guideYour first SMS with curl and Node
From API key to your first send: the full call with curl, the same one in Node 22 with no dependencies, and how to read status, parts and price in the response.
Read the guideIdempotency and safe retries
A timeout does not mean "not sent". How to use the Idempotency-Key header to retry without ever doubling sends and charges.
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