> ## Documentation Index
> Fetch the complete documentation index at: https://hyperlocalise.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Translate CSV localization files with Hyperlocalise

> Translate key-value CSV files and locale-column tables.

CSV catalogs exchange messages in rows and columns. Column structure determines which content Hyperlocalise treats as keys and translation values; use the source layout below before translating an existing spreadsheet export.

Supported extensions: `.csv`.

## Source file

Save this example as `locales/en-US/messages.csv`.

```csv theme={null}
key,value
home.title,Welcome
home.greeting,"Hello, {name}!"
```

## Configure your files

Use this `i18n.yml` for the example, or add its file mapping to your existing bucket.
See [path templates](/cli/configuration/path-templates) for other layouts.

```yaml theme={null}
locales:
    source: en-US
    targets:
        - es-ES

buckets:
    messages:
        files:
            - from: locales/en-US/messages.csv
              to: locales/{{target}}/messages.csv

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

## Translate

[Install the CLI](/cli/getting-started/install) and set `OPENAI_API_KEY` in your
project's `.env.local` or shell. You can also configure another
[AI provider](/cli/providers/overview).

```bash theme={null}
hyperlocalise run --dry-run
hyperlocalise run
```

The dry run previews the work. The second command writes translations to the
configured target path and updates the lockfile.

## Behavior and limitations

* The example uses a header row with `key` and `value`. CSV quoting handles commas and multiline values.

* Locale-column layouts are also supported. Source and target locales select the corresponding columns.

* Existing rows retain their order; newly appended keys are sorted. CSV quoting and line endings may be normalized.

* This page covers translation files. For `status --output csv`, see [Command output](/cli/reference/output-formats).

## Next steps

* [Check translations](/cli/commands/check) before committing generated files.
* [Local translation workflow](/cli/workflows/local-generation) explains repeat runs.
* [Browse all file formats](/cli/reference/formats/overview).

## Related formats

* [JSON localization](/cli/reference/formats/json)
* [gettext PO](/cli/reference/formats/gettext)