---
description: How react-i18next, vue-i18n, next-intl and other libraries fit the files that git8n edits.
---

# Libraries

git8n reads [i18next JSON](./i18next.md) files, in one folder for each
language. This page tells, for each library, what fits that layout and what
`git8n check` reads in its texts. Each claim was tried with `git8n check`.

## react-i18next and next-i18next

They read i18next JSON, so everything on [i18next JSON](./i18next.md) applies.
The default path of `i18next-http-backend` and of next-i18next is
`public/locales/<language>/<namespace>.json`, which `git8n check` finds with
no `--locales`.

## i18next-icu

The files are i18next JSON, and the texts are [ICU MessageFormat](./icu.md).
Both pages apply.

## vue-i18n

The texts of vue-i18n fit, with limits. Run `git8n check --syntax vue-i18n`:
with no `--syntax`, the linked messages and the `|` plurals are text, as they
are for i18next.

| vue-i18n                                   | git8n                                                              |
| ------------------------------------------ | ------------------------------------------------------------------ |
| Named `{name}`, `{user-id}`                | Read, as an ICU argument                                           |
| List `{0}`                                 | Read, as an ICU argument                                           |
| Plural `no car \| one car \| {count} cars` | `--syntax vue-i18n`: the branches are counted, `{count}` is read   |
| Linked `@:common.ok`, `@.lower:common.ok`  | `--syntax vue-i18n`: read as `@:common.ok`, and its key must exist |
| Literal `{'@'}`, escaped `\@` and `\|`     | Text                                                               |

- A translation keeps the links of its source. The modifier, `.lower` in
  `@.lower:common.ok`, can change: a language can need a capital where
  another does not.
- The key of a link names a key of a file of the source language: `ok`, as one
  object of a language holds it once you merge the files, or `common.ok` for
  the key `ok` of `common.json`. git8n reads the merge from the links: one merge must
  resolve them all. When some links resolve in one merge only and others in
  the other only, the merge of the most links wins, and the other links are
  errors. With as many links in each form, no merge wins, and each of them is
  an error. A key that no file holds is an error of
  [`unknown-link`](../reference/rules/unknown-link.md). vue-i18n ends the key
  only at a space, `{`, `(`, `)`, `|` or `@`: in `@:nav.home!`, the key is
  `nav.home!`. Write `@:nav.home{'!'}`.
- A translation has as many branches as its source. A plural of 2 branches
  and one of 3 do not pick the same branch for 0, so another number is a
  warning of [`plural-branches`](../reference/rules/plural-branches.md). An
  application that sets `pluralRules` for a language can need other numbers:
  `--max-warnings` lets them pass.
- A `|` is a branch only in a source that has branches, and only in a text
  with no ICU choice: a `|` that a translation adds to a plain text is text.
- `{0}` and the names `{user-id}`, `{total$}` are read with any `--syntax`.

The layout is the other limit. A vue-i18n project often keeps one file for
each language (`locales/en.json`), or its messages in JavaScript. git8n reads
neither: put the messages in `locales/<language>/<name>.json`, and merge the
files of a language when you load them.

## next-intl

next-intl writes [ICU MessageFormat](./icu.md), which `git8n check` reads.
Its default layout, one file for each language (`messages/en.json`), is not
read: `git8n check` stops with `G8N1005`. Put the messages in
`messages/<language>/<name>.json`, and merge them in the request config.

## FormatJS and react-intl

The texts are ICU MessageFormat. Two habits of these projects do not fit:

- one file for each language (`lang/en.json`);
- flat ids that hold dots, such as `"app.title"`. git8n reads them, but the
  editor writes a key as nested objects: see [The keys](./i18next.md#the-keys).

The files that `formatjs extract` writes hold objects
(`{ "defaultMessage": …, "description": … }`), not strings: they are not read.

## Not supported

- One file for each language, whatever the library.
- Messages in JavaScript, TypeScript, YAML, gettext, XLIFF or ARB.
- A link whose key comes from a value, `@:{name}`: its key is not checked.