Unknown's avatar Namal Fernando 10:29 am on 14th May 2026
Tags: ,   

Building a Simple Translation REST API using Google Cloud Translation API, FastAPI, and Python

1. Python Code

Create a file named: google_cloud_tr.py

from fastapi import FastAPI
from google.cloud import translate_v3 as translate
app = FastAPI()
PROJECT_ID = "<your-project-id>"
LOCATION = "global"
@app.get("/translate")
def translate_text(text: str, target: str):
    client = translate.TranslationServiceClient()
    parent = f"projects/{PROJECT_ID}/locations/{LOCATION}"
    response = client.translate_text(
        request={
            "parent": parent,
            "contents": [text],
            "mime_type": "text/plain",
            "target_language_code": target,
        }
    )
    return {
        "translatedText": response.translations[0].translated_text
    }

2. Provide the Google Cloud JSON Key as an Environment Variable

  • Search for and enable: Cloud Translation API
  • Double check: APIs & Services > Enabled APIs
  • Then: IAM & Admin > Service Accounts

Steps:

  • Create a Service Account
  • Add one of these roles:
    • Cloud Translation API User
    • Cloud Translation Admin
    • or a higher role
  • Create and download the JSON key (e.g.: service-account.json)
  • Save it inside your project directory (D:\path\to\directory\google-cloud-translation\)

Provide the JSON key path as an environment variable:

$env:GOOGLE_APPLICATION_CREDENTIALS="D:\path\to\directory\google-cloud-translation\service-account.json"

3. Run the API

Create and activate a virtual environment:

python -m venv venv
.\venv\Scripts\Activate.ps1

Install prerequisites:

pip install google-cloud-translate fastapi uvicorn

Run the API:

uvicorn google_cloud_tr:app --reload

4. Test the Result

Request:

GET http://127.0.0.1:8000/translate?text=The Strait of Hormuz has emerged as the central battleground of the Iran conflict.&target=es

Example response:

{
"translatedText": "El Estrecho de Ormuz ha surgido como el principal campo de batalla del conflicto con Irán."
}

Note:

Google Cloud Translation mainly handles language translation.
For advanced regional localization (such as Puerto Rico Spanish, slang, or tone-specific translation), an LLM-based approach like OpenAI may provide more natural results. Please refer this.

#fastapi, #python