API POST /thing-translator

Method: POST Path: /thing-translator Controller: src/modules/thing-translator/thing-translator.controller.ts Service: src/modules/thing-translator/thing-translator.service.ts

Purpose

Accepts a base64-encoded image and a target language code, runs Google Cloud Vision label detection on the image to identify the primary object, then returns the detected label translated into the target language. Used by the Currency Lens and Thing Translator features in the iOS app.

Request

Body (ThingTranslateRequestDto):

Field	Type	Required	Description
`imageBase64`	`string`	Yes	Base64-encoded image bytes (no data-URL prefix)
`targetLang`	`string`	No	BCP-47 language code (e.g. `"th"`, `"ja"`); defaults to `"en"` from config

Validation: ValidationPipe with whitelist: true, forbidNonWhitelisted: true, transform: true — applied globally in main.ts.

Response

200 OK:

{
  "label": "Coffee cup",
  "confidence": 0.9721,
  "translated": "แก้วกาแฟ"
}

Field	Type	Description
`label`	`string`	Primary label from Google Vision (English)
`confidence`	`number`	Vision confidence score 0–1
`translated`	`string`	`label` translated to `targetLang`

Error: Throws the raw error from Google Cloud SDK — no custom HTTP status mapping; NestJS default exception filter returns 500.

Flow Diagram

External Dependencies

Service	Client	Key call
Google Cloud Vision	`GoogleVisionClient` (`@google-cloud/vision`)	`client.labelDetection(imageBuffer)` → first annotation
Google Cloud Translate	`GoogleTranslateClient` (`@google-cloud/translate`)	`client.translateText({ parent, contents, targetLanguageCode })`