TransformNet API

Overview

The TransformNet OCR API accepts an image (as a URL or base64-encoded string) and returns a structured JSON response containing the extracted value, unit, confidence score, and any additional instrument-specific data.

No DoForms account is required to use the REST API. Authentication is via an API key obtained from your TransformNet dashboard.

Authentication

All API requests must include your API key in the Authorization header using the Bearer scheme.

Authorization: Bearer tnk_your_api_key_here

API keys are generated from your dashboard under API Keys. Each key is shown only once at creation — store it securely. Keys can be revoked at any time.

Base URL

All endpoints below are relative to this base URL. All requests and responses use JSON. Include Content-Type: application/json on POST requests.

Rate Limits

Rate limits are applied per tenant. Every response includes the following headers so you can track your usage:

X-RateLimit-Limit:     60      # requests allowed in the window
X-RateLimit-Remaining: 58      # requests remaining in the window
X-RateLimit-Window:    1m      # window duration

When a rate limit is exceeded the API returns 429 Too Many Requests with a Retry-After header indicating how many seconds to wait before retrying.

Endpoints

// POST https://transformnet.com/api/v1/ocr/analyse
{
  "imageUrl":   "https://example.com/images/meter.jpg",
  "imageType":  "OPTICAL_POWER_METER"
}

{
  "imageBase64": "data:image/jpeg;base64,/9j/4AAQSkZJRgAB...",
  "imageType":   "VIN"
}

{
  "success":        true,
  "imageType":      "OPTICAL_POWER_METER",
  "extractedValue": "-9.79",
  "unit":           "dBm",
  "confidence":     0.96,
  "confidenceLabel":"High",
  "additionalData": {
    "secondaryValue": "-12.30",
    "secondaryUnit":  "dBm",
    "wavelength":     "1550nm"
  },
  "rawText":        "",
  "errors":         [],
  "processingMs":   842
}

{
  "success":        false,
  "imageType":      "OPTICAL_POWER_METER",
  "extractedValue": "",
  "confidence":     0.0,
  "confidenceLabel":"Low",
  "errors":         ["Could not locate meter display in image"],
  "processingMs":   610
}

{
  "types": [
    { "type": "OPTICAL_POWER_METER",  "description": "Optical power / signal level meter (dBm, dB, dBµV)" },
    { "type": "VIBRATION_METER",      "description": "Vibration analyser / accelerometer (m/s², g, Hz)" },
    { "type": "VIN",                  "description": "Vehicle Identification Number label or plate" },
    { "type": "ODOMETER",             "description": "Vehicle odometer / mileage display" },
    { "type": "ANALOG_METER",         "description": "Analogue dial or needle-based gauge" }
  ]
}

Image Types

Pass one of these values in the imageType field to skip auto-detection and improve accuracy. When omitted, the service will infer the type from the image.

Response Fields

Errors

Error responses use a consistent envelope:

{
  "message": "Provide either imageUrl or imageBase64.",
  "detail":  "Both are missing."
}

Zapier Integration

The TransformNet API works with Zapier's built-in Webhooks by Zapier action — no custom app required. Use it to connect image extraction to Google Sheets, Salesforce, Airtable, Slack, or any of Zapier's 6,000+ apps.

Setting up the Webhooks action

Example Zap — Image URL to Google Sheets

This example triggers when a new record arrives in your system containing an image URL, calls TransformNet to extract the reading, and appends the result to a Google Sheet.

Trigger — any app that provides an image URL

Use whatever trigger is appropriate for your workflow — a new row in Google Sheets, a form submission, a new file in Dropbox, or a Webhooks catch hook. The only requirement is that your trigger step exposes an image URL that TransformNet can fetch.

Action 1 — Webhooks by Zapier (POST)

// URL
https://transformnet.com/api/v1/ocr/analyse

// Headers
Authorization: Bearer tnk_your_api_key_here
Content-Type:  application/json

// Body (JSON)
{
  "imageUrl":  "{{trigger.image_url}}",
  "imageType": "OPTICAL_POWER_METER"
}

Action 2 — Google Sheets (Append Row)

Map the following fields from the TransformNet response to your spreadsheet columns: