Message formatting

18ways uses waysParser by default. That parser is what lets you keep the source copy readable while still handling variables and locale-aware formatting.

Variables

Use braces for variables. With <T>, you can keep the value inline next to the message.

import { useT } from '@18ways/react';
 
export function WelcomeMessage() {
  const t = useT();
 
  return (
    <p>
      {t('Welcome back, {name}', {
        vars: { name: 'Ada' },
      })}
    </p>
  );
}

Pluralization

Use ICU-style plural blocks when the sentence genuinely changes shape.

import { T } from '@18ways/react';
 
export function InboxCount({ count }: { count: number }) {
  return (
    <T>{{ count, format: 'plural, =0{No messages} =1{One message} other{{count} messages}' }}</T>
  );
}

Dates and money

If you pass a real Date or a money-like object with amount and currency, 18ways will format it automatically even with a bare placeholder like {publishedAt} or {renewalTotal}.

Use the explicit formatter only when you want to control the output, such as dateStyle:long or a custom money divisor.

import { T } from '@18ways/react';
 
export function BillingSummary() {
  const publishedAt = new Date('2026-03-14T09:00:00Z');
  const renewalTotal = {
    amount: 1900,
    currency: 'USD',
  };
 
  return (
    <>
      <p>
        <T>Last updated {{ publishedAt }}</T>
      </p>
      <p>
        <T>Renewal total {{ renewalTotal }}</T>
      </p>
      <p>
        <T>Detailed date: {{ publishedAt, format: 'date, long' }}</T>
      </p>
    </>
  );
}

By default, money amounts are treated as minor units. If you already have major units, use the explicit money formatter with divisor: 1.

Select blocks

Use select when the copy depends on a small set of discrete values.

import { T } from '@18ways/react';
 
export function SignInState({ isSignedIn }: { isSignedIn: boolean }) {
  return (
    <T vars={{ name: 'Ada' }}>
      {{
        isSignedIn,
        format:
          'select, true{Welcome back, {name}} false{Sign in to continue} other{Sign in to continue}',
      }}
    </T>
  );
}

Component composition

Keep the sentence together in JSX and 18ways will preserve the real UI structure for common cases like <T><a href="#">Click here</a> to see more</T> without you stitching fragments together by hand.

import { T } from '@18ways/react';
 
export function HeroCta() {
  return (
    <T>
      <a href="/pricing">Click here</a> to see more
    </T>
  );
}

Turning the parser off

@18ways/react lets you set messageFormatter="none" at the root or provide a custom formatter function. That is an advanced escape hatch, not the default path.

Practical rule

If the sentence can be written as a complete phrase with a few variables, keep it in one message. That makes translation quality dramatically better than stitching fragments together in code.