One WhatsApp agent, every customer's language: Malay, English, Chinese, Tamil and the mix in between

A Kuala Lumpur clinic hears from patients in Malay, English, Mandarin and Tamil before lunch, often two in the same message. A receptionist who speaks three of the four is rare and expensive. An AI agent answers each customer in the language they used, from a knowledge base you wrote once in one language.

By Ritchie, ReplyKit · Published 5 September 2026 · 6 min read

How it works

• Detection per message. The agent reads the customer's language from what they wrote, not from a setting, so a customer who switches from English to Malay mid-conversation gets Malay back.
• One knowledge base. Write prices, services and policies once, in whichever language is easiest for you. The agent answers from them in the customer's language.
• Instructions in any language. Write the agent's instructions in English, Malay or Chinese; it follows them the same way.
• Primary language. Set it in Settings for greetings and for messages where the customer's language is ambiguous, such as "ok" or a phone number.
• Voice notes. Transcribed in the language spoken, then answered in that language.

Manglish, Singlish and code-switching

"Boss, Saturday ada slot tak? Around 3pm can?" is one sentence in three languages. The agent handles it: it understands the request and replies in the same register, usually mirroring the dominant language and keeping it casual. Two things help. First, tell the agent in the instructions what register you want: "friendly and casual, match the customer, but keep prices and addresses exact". Second, keep proper nouns fixed: instruct it never to translate your business name, service names, staff names or street names. Nothing erodes trust faster than a translated shop name.

Setting it up well

1. Write the knowledge base in your strongest language. Do not maintain three versions; you will forget to update two of them.
2. Set your primary language in Settings. For most Malaysian businesses that is Malay or English; for Singapore, English.
3. Add to the instructions: "Reply in the customer's language. Keep business, service, staff and place names exactly as written. Use formal Malay for older customers unless they write casually."
4. Test with the same question in four languages and a mixed one. Check that prices and addresses are identical in every reply.
5. Watch the unanswered-questions list: a question phrased in a language you did not anticipate is still just a question to teach.

Where a person is still better

Nuance around complaints, negotiation and anything emotional reads differently across languages, and the agent should hand those to a person regardless of language. Formal written Chinese for legal or medical matters is another place to keep a human. For everything else, the everyday enquiries that make up most of the volume, the agent's language coverage is wider than any front desk.

Frequently asked questions

ReplyKit is an independent product and is not affiliated with or endorsed by Meta or WhatsApp. This article is general guidance for running a small business, not legal, financial or regulatory advice.