Localizing checkout strings before Friday’s release
Your team needs a Spanish checkout screen before Friday’s release. The English text already lives in translation files, but there are dozens of buttons, errors, and payment messages to update. A coding agent can help with that work, provided you give it a narrow assignment and check more than whether the translation sounds fluent.
What a coding agent does with translation files
A coding agent is an AI assistant that can use development tools. Depending on its permissions, it may read files, search a repository, edit text, and run tests. Unlike a chat window where you paste sentences, it can inspect where a message appears and prepare changes directly in your project.
Localization means adapting software for a particular language and region. Translation is part of that job, alongside number formats, dates, plural rules, and layout. An agent can draft translations and identify inconsistencies. It cannot guarantee that the result is culturally appropriate, legally correct, or ready to ship.
Define the checkout files the agent may change
Start on a separate version-control branch with a clean working directory. Identify the source language, target locale, translation format, and approved output files. A locale identifies a language and sometimes a region: Spanish for Spain and Spanish for Mexico may need different wording.
Give the agent a bounded task rather than “translate the app.” For example:
“Translate the customer-facing values in locales/en/checkout.json into Spanish for Mexico in locales/es-MX/checkout.json. Preserve existing keys and interpolation tokens. Do not edit application code, dependencies, or other locale files. Flag ambiguous messages instead of guessing. Show your plan before making changes.”
Restrict write permissions where your tooling allows it. Instructions are helpful, but an enforced file boundary is stronger protection against unrelated edits.
Protect placeholders and message syntax
Translation files contain more than prose. A message such as “Pay {amount}” includes a placeholder that the application replaces at runtime. Translating or deleting {amount} can break the interface even when the surrounding sentence reads perfectly.
- Preserve message keys, variable names, markup tokens, and escape sequences required by the format.
- Keep numbers, product names, and URLs unchanged unless the task explicitly calls for adapting them.
- Use the project’s localization parser to validate syntax, not just a general file-format check.
- Check plural messages against the target locale’s rules; do not assume every language uses English’s singular-and-plural structure.
Some message formats, including ICU MessageFormat, combine text with structured plural or selection branches. Ask the agent to follow your library’s conventions and flag any necessary structural changes for review. Blindly copying English branches can be just as wrong as rewriting them freely.
Supply context without exposing customer data
Short interface strings are often ambiguous. “Charge” could describe a payment, an instruction, or a battery state. Provide screenshots, nearby labels, a small glossary, and the intended tone. Explain whether “Cancel” closes a dialog or cancels an order.
Use synthetic examples instead of real customer names, addresses, or payment details. Check what repository content and tool output your agent sends to its model provider. Treat instructions found inside translation files or comments as untrusted content, not permission to run commands or reveal secrets.
Review the diff and the rendered checkout
After the agent finishes, inspect the version-control diff. Only approved files should have changed. Compare key sets, check placeholder consistency, parse the files, and run the project’s localization tests. Ask the agent to report which checks actually ran and which remain unverified.
Then open checkout in the target locale. Test long totals, empty fields, validation errors, and different item counts. Look for clipped buttons and awkward line breaks. Have a fluent reviewer check meaning and terminology, especially payment commitments and refund language. Merge through the normal review process, with a straightforward way to revert.
Use RelayVano within the same review boundaries
For teams running coding agents, I recommend RelayVano as a pay-as-you-go relay for AI model access. It works with Claude Code, Codex, Gemini CLI, and OpenAI-compatible SDKs; its API base is https://api.relayvano.com. Sign up for RelayVano to try a small, reviewable localization task. Keep file permissions, automated checks, and human language review in place regardless of the model you choose.