Vismrit API platform

Gst API

GST data workflow API with session, captcha, data and captcha-refresh stages.

Developer API

Gst API

The GST API exposes a session-based workflow through the published API reference. Published routes include starting the flow, submitting GSTIN plus captcha data and refreshing captcha state when needed. This lets an application orchestrate the existing GST workflow through a controlled API subscription.

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Capabilities

What this API is designed to do

GST data workflow API with session, captcha, data and captcha-refresh stages.

Start a GST workflow session
Receive or refresh captcha state
Submit GSTIN and captcha data through the published POST route
Apply API-key, quota and whitelist controls around requests
Use cases

Where it can fit

These are common integration scenarios; choose the approach that fits your application and subscription plan.

Business onboarding workflows that need GST-related data
Internal vendor or customer verification processes
Applications that need to orchestrate the existing GST session and captcha flow
Endpoint catalogue

Published routes and methods

Use the published routes and methods below when integrating this API.

MethodRoutePurpose
ANY/gstIndex
POST/gst/dataBody JSON: { sessionId, GSTIN, captcha }
GET/gst/refresh_captcha(Optional) GET /api/v1/gst/refresh-captcha?sessionId=...
GET/gst/startWS: send {type:"start"} -> receive {type:"captcha", sessionId, captcha(base64)}
Integration reference

Authentication, request shape and response handling

Use these examples as a quick integration reference and check the current API documentation before production use.

Authentication & access

Use Authorization: Bearer YOUR_API_KEY or X-API-Key. Keep the returned sessionId between GST start, data submission and captcha-refresh requests.

Example request
curl -X GET "https://api.sinhcoms.com/gst/start" 
  -H "Authorization: Bearer YOUR_API_KEY"

curl -X POST "https://api.sinhcoms.com/gst/data" 
  -H "Authorization: Bearer YOUR_API_KEY" 
  -H "Content-Type: application/x-www-form-urlencoded" 
  --data-urlencode "sessionId=SESSION_ID" 
  --data-urlencode "gst=GSTIN_VALUE" 
  --data-urlencode "captcha=CAPTCHA_CODE"

curl -X GET "https://api.sinhcoms.com/gst/refresh_captcha?sessionId=SESSION_ID" 
  -H "Authorization: Bearer YOUR_API_KEY"
Example response
{
  "sessionId": "SESSION_ID",
  "image": "data:image/png;base64,..."
}

# /gst/data returns the GST workflow data payload when the upstream service succeeds.
Error handling

Documented error states

400sessionId, GSTIN/gst or captcha is missing
401API key authentication or product authorization failed
429Daily request limit exceeded
500GST processing failed
502Unexpected upstream response
Integration flow

From subscription to first request

Use the customer dashboard as the control point for keys, whitelist rules and plan limits.

01

Choose a GST API tier

02

Generate or assign an API key

03

Call the start route and retain the returned session context

04

Submit GSTIN and captcha data to the published data route

05

Refresh captcha when required and handle errors explicitly

Plans

Choose the request capacity you need

Pricing and limits below are read from the active subscription tiers in the API system.

Star

INR 499.00/month
Subscribe

  • 100,000 requests/day
  • 3,000,000 requests/month
Integration notes

Before you go live

GST data can be business-sensitive. Validate your lawful basis and downstream use, and do not log sensitive payloads unnecessarily.

Contact Information

India

Talk to us+91 9123288803support@vismrit.tech