i18n config

File overview

i18n.yml controls locales, file mapping, model profiles, and optional advanced routing. i18n.jsonc is still supported for compatibility.

Starter config

locales:
  source: en-US
  targets:
    - es-ES

buckets:
  ui:
    files:
      - from: packages/ui/lang/{{source}}.json
        to: apps/web/lang/{{target}}.json

llm:
  profiles:
    default:
      provider: openai
      model: gpt-5.2

This is the shape written by hyperlocalise init. When groups is omitted, Hyperlocalise automatically uses one implicit default group with:

all locales from locales.targets
all bucket names from buckets

Locales

locales.source: source locale.
locales.targets: list of target locales.
optional locales.fallbacks: fallback order per locale.

Buckets

buckets map source files to target output templates. Each file mapping uses:

from: source path template
to: target path template

Use {{source}}, {{target}}, and {{localeDir}} in templates. {{localeDir}} resolves to an empty segment when target equals source, and to the target locale otherwise.

PHP array locale mapping patterns

Laravel-style locale arrays can be mapped directly when each file returns one static PHP array.

buckets:
  app:
    files:
      - from: resources/lang/en/messages.php
        to: resources/lang/{{target}}/messages.php
      - from: resources/lang/en/validation.php
        to: resources/lang/{{target}}/validation.php

Supported PHP locale files must begin with <?php and return a static [...] or array(...) literal. Hyperlocalise translates string leaves, flattens nested keys with dotted paths, and preserves comments, ordering, and array syntax when writing. Dynamic PHP such as variables, function calls, constants, declare(...), or interpolated double-quoted strings is intentionally rejected. Supported locale file extensions include .json, .jsonc, .yaml, .yml, .php, .xml, .resx, .arb, .xlf, .xlif, .xliff, .po, .html, .liquid, .md, .mdx, .strings, .stringsdict, and .csv. YAML/YML locale files should be mapping-shaped files with string leaves. Nested mappings become dotted keys, sequences become [index] keys, and writeback rewrites existing string leaves while preserving key order/comments where possible. Mapping keys cannot contain ., [, or ] because those characters are reserved for flattened paths. Non-string scalar leaves such as numbers, booleans, nulls, timestamps, anchors, and aliases are rejected to avoid silently corrupting metadata.

buckets:
  ui:
    files:
      - from: packages/ui/lang/{{source}}.yaml
        to: apps/web/lang/{{target}}.yaml

Generic XML mappings can point at non-Android XML locale files:

buckets:
  xml:
    files:
      - from: locales/en-US.xml
        to: locales/[locale].xml

XML entries must be text-only leaf elements keyed by key, id, or name, or nested path-shaped leaves. Android <resources> files, mixed-content XML, and CDATA-preserving writeback are not handled by the generic XML parser.

CSV file mapping patterns

Use bucket file mappings to model CSV workflows. Per-locale files:

{
  "from": "translations/en.csv",
  "to": "translations/[locale].csv"
}

Shared multi-locale file:

{
  "from": "translations/catalog.csv",
  "to": "translations/catalog.csv"
}

For shared multi-locale CSV files, keep one key column and one target locale column that run can update consistently.

Fluent file mapping patterns

Use .ftl mappings for Mozilla Fluent locale files:

{
  "from": "locales/en-US/messages.ftl",
  "to": "locales/[locale]/messages.ftl"
}

Hyperlocalise supports Fluent messages, attributes, multiline values, and select/plural values as full translation units. Attributes use dotted keys such as brand.title. Fluent terms are not supported and fail during parsing.

JS/TS locale module patterns

Use JavaScript or TypeScript locale module mappings when your app imports locale objects directly:

buckets:
  web:
    files:
      - from: apps/web/messages/{{source}}.ts
        to: apps/web/messages/{{target}}.ts

Supported modules must export one static object, for example:

export default {
  home: {
    title: "Welcome",
    cta: "Start now",
  },
} as const;

Hyperlocalise preserves comments, imports, export syntax, and non-message module text. It rejects dynamic values, computed keys, spread properties, multiple exported locale objects, and interpolated template literals.

Apple string catalog mapping patterns

Use .xcstrings mappings for Xcode string catalogs:

{
  "from": "ios/en.lproj/Localizable.xcstrings",
  "to": "ios/[locale].lproj/Localizable.xcstrings"
}

Hyperlocalise writes target values into localizations[targetLocale] and preserves catalog metadata. status and check read the requested target locale from the catalog. Variant and substitution source entries must include a source-language localization so Hyperlocalise can extract the source forms safely.

Android XML string resource mappings

Android XML support is intentionally scoped to string resource files named strings.xml under res/values* directories. Use Android locale qualifier names in your target paths:

buckets:
  android:
    files:
      - from: app/src/main/res/values/strings.xml
        to: app/src/main/res/values-{{target}}/strings.xml

Supported resource entries are <string name="..."> and <plurals name="..."><item quantity="...">. Resources marked translatable="false" are preserved and skipped. Unsupported translatable resource shapes such as <string-array> fail closed so they are not silently dropped.

Java properties file mapping patterns

Use .properties mappings for Java resource bundles with one file per locale:

buckets:
  java:
    files:
      - from: src/main/resources/messages_{{source}}.properties
        to: src/main/resources/messages_{{target}}.properties

Supported entries are flat Java properties keys with string values. Hyperlocalise preserves comments, separators, and key order on write; translated values are written as escaped single-line .properties values.

Groups

groups.<name> defines what to process together.

targets: subset of locales.targets
buckets: list of bucket names

groups is optional for beginner configs. Add it when you want to split execution by locale or file set.

LLM profiles

llm.profiles.<name> fields:

provider: openai, azure_openai, anthropic, gemini, bedrock, lmstudio, groq, mistral, or ollama
model: provider model id
system_prompt (optional): explicit system-message template
user_prompt (optional): explicit user-message template
prompt (deprecated, optional): legacy prompt template used as system fallback

Prompt variables:

{{source}}
{{target}}
{{input}}

Rules

llm.rules choose profile per group.

priority: higher wins
group: group name
profile: profile name

llm.rules is optional. When no rule matches a group, Hyperlocalise falls back to llm.profiles.default.

Hyperlocalise

hyperlocalise configures the public Hyperlocalise web API for sync push and sync pull.

project_id (required unless project_id_env is set): Hyperlocalise project ID.
project_id_env (optional): environment variable that contains the project ID.
api_base_url (optional): API base URL. Defaults to https://hyperlocalise.com/api.
api_key_env (optional): environment variable that contains the API key. Defaults to HYPERLOCALISE_API_KEY.
timeout_seconds (optional): HTTP timeout for sync API calls. Defaults to 1200.

sync push uploads source files. sync pull downloads translated files reconstructed by the API. Translation jobs are created by Hyperlocalise automation or in the web app, not by the CLI.

Cache

cache configures the remote caching client.

enabled (optional): enable remote caching for run.
endpoint (optional unless enabled=true): remote cache service endpoint.
project_key_env (optional unless enabled=true): environment variable that contains the project cache key.
timeout_seconds (optional): remote cache request timeout in seconds.

Advanced example

locales:
  source: en-US
  targets:
    - fr-FR
    - es-ES
  fallbacks:
    fr-FR:
      - es-ES
      - en-US

buckets:
  ui:
    files:
      - from: packages/ui/lang/{{source}}.json
        to: apps/web/lang/{{target}}.json
  docs:
    files:
      - from: docs/{{source}}/**/*.mdx
        to: docs/{{target}}/**/*.mdx

groups:
  app:
    targets:
      - fr-FR
      - es-ES
    buckets:
      - ui
  docs:
    targets:
      - fr-FR
    buckets:
      - docs

llm:
  profiles:
    default:
      provider: openai
      model: gpt-5.2
    docs_review:
      provider: openai
      model: gpt-5.2
      system_prompt: You are a senior technical translator.
      user_prompt: |-
        Translate from {{source}} to {{target}}.

        Keep Markdown and MDX syntax intact.

        {{input}}
  context_memory:
    provider: openai
    model: gpt-5.2
  rules:
    - priority: 100
      group: docs
      profile: docs_review

hyperlocalise:
  project_id: project_123
  api_base_url: https://hyperlocalise.com/api
  api_key_env: HYPERLOCALISE_API_KEY
  timeout_seconds: 1200

cache:
  enabled: true
  endpoint: dns:///cache.internal:443
  project_key_env: HYPERLOCALISE_CACHE_PROJECT_KEY
  timeout_seconds: 5

Generate a starter

hyperlocalise init

Then edit the generated i18n.yml for your project.

Validation tips

If you omit groups, every bucket runs for every target locale.
Keep group targets inside locales.targets.
Keep group buckets aligned with buckets keys.
Keep profile names consistent between profiles and rules.
Use hyperlocalise for sync push and sync pull.
Keep storage for provider-specific TMS adapter configuration.

Getting Started

Configuration

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Providers

TMS Adapters

Troubleshooting

Reference & Concepts

Contributing

Legal

File overview

Starter config

Locales

Buckets

PHP array locale mapping patterns

CSV file mapping patterns

Fluent file mapping patterns

JS/TS locale module patterns

Apple string catalog mapping patterns

Android XML string resource mappings

Java properties file mapping patterns

Groups

LLM profiles

Rules

Hyperlocalise

Cache

Advanced example

Generate a starter

Validation tips

​File overview

​Starter config

​Locales

​Buckets

​PHP array locale mapping patterns

​CSV file mapping patterns

​Fluent file mapping patterns

​JS/TS locale module patterns

​Apple string catalog mapping patterns

​Android XML string resource mappings

​Java properties file mapping patterns

​Groups

​LLM profiles

​Rules

​Hyperlocalise

​Cache

​Advanced example

​Generate a starter

​Validation tips

File overview

Starter config

Locales

Buckets

PHP array locale mapping patterns

CSV file mapping patterns

Fluent file mapping patterns

JS/TS locale module patterns

Apple string catalog mapping patterns

Android XML string resource mappings

Java properties file mapping patterns

Groups

LLM profiles

Rules

Hyperlocalise

Cache

Advanced example

Generate a starter

Validation tips