Encoding and utilities

estimateSegments, isGsm7, the GSM-7 tables, SEGMENT_LIMITS, isE164, maskPhoneNumber, redactText, and the other root helpers.

Synchronous helpers with no network access. The encoding functions live in @opencoredev/sms-sdk/encoding. estimateSegments and isGsm7 are also exported from the root.

`estimateSegments(body)`

Estimates the encoding and segment count for a message body.

import { estimateSegments } from "@opencoredev/sms-sdk/encoding";

const preview = estimateSegments("Café opens at 9 € 5");
console.log(preview.encoding, preview.units, preview.segments); // "gsm7" 20 1

é is in the GSM-7 basic table and € is in the extension table, so it counts 2 septets.

Returns: `SegmentPreview`

Field	Type	Meaning
`encoding`	`"gsm7" \| "ucs2"`	GSM-7 when every character is in the basic or extension table.
`segments`	`number`	Estimated segments. `0` for an empty body.
`units`	`number`	Septets (extension characters count 2) or UTF-16 code units.
`unitsPerSegment`	`number`	160 or 153 for GSM-7, 70 or 67 for UCS-2.
`remainingInSegment`	`number`	Units left before another segment is needed.
`containsUnicode`	`boolean`	At least one character forced UCS-2.
`nonGsmCharacters`	`readonly string[]`	Distinct characters that forced UCS-2, in order of first appearance.

Extension characters and surrogate pairs never split across segments, and nothing is transliterated. The result is an estimate, not a price. See Segments and billing.

`isGsm7(text)`

Returns true when every character is in the GSM-7 basic or extension table.

`GSM7_BASIC_CHARACTERS` and `GSM7_EXTENSION_CHARACTERS`

Strings holding the GSM 03.38 basic alphabet, one septet each, and the extension table, two septets each. The extension table is form feed, ^, {, }, \, [, ~, ], |, and €.

`isE164(value)`

import { isE164 } from "@opencoredev/sms-sdk";

console.log(isE164("+14155550123"), isE164("+1 415 555 0123"), isE164("0044207946000")); // true false false

A type guard (value is E164) for ^\+[1-9]\d{1,14}$. It checks format only, not whether the number exists or receives SMS. It accepts unknown, so you can pass process.env values directly.

`maskPhoneNumber(value)`

Masks a number for logs, keeping the +, the first digit, and the last two digits: +14155550123 becomes +1********23. Short strings are fully masked.

`redactText(text)`

Makes provider text safe to log. It masks digit runs that look like phone numbers, removes control characters, and truncates to 200 characters. Use it in custom adapters for details.message.

import { maskPhoneNumber, redactText } from "@opencoredev/sms-sdk";

console.log(maskPhoneNumber("+14155550123")); // "+1********23"
console.log(redactText("The 'To' number +14155550123 is not valid")); // "The 'To' number +1********23 is not valid"

`resolveSender(from)` and `supportsSender(capabilities, sender)`

resolveSender validates an SmsFrom and returns { kind: "ok", sender: SmsSender }, { kind: "missing" }, or { kind: "invalid", message }. supportsSender returns whether an adapter’s capabilities.senderTypes allow that sender. The client uses both. They are exported for adapter authors.

`isSmsError(value)` and `isFallbackEligible(category)`

isSmsError is a type guard for any SDK error. isFallbackEligible returns true for auth, rate_limited, sender, and account. See Errors.

Types

E164, SegmentPreview, SmsEncoding, and SenderResolution are exported as types from @opencoredev/sms-sdk.