GST on advertising services

tip

Status: LIVE — Real-time data from the upstream regulator. Updated on the regulator's publication cadence.

What it does

Advertising-service GST is a thicket of SAC codes (998361, 998362, 998363) with edge cases for OOH, digital, programmatic, and influencer marketing. Our API exposes the canonical SAC-to-rate mapping with place-of-supply rules and TDS interaction notes — useful for digital agencies, brand teams, and media-buying platforms.

Base URL

https://gstad.sahayakonline.co.in/v1/

Endpoints

Method	Path	Description
GET	/health	Liveness probe
GET	/v1/gst/ad/rate	All advertising SACs with current rate
GET	/v1/gst/ad/rate/{sac}	Single SAC with rules and history
GET	/v1/gst/ad/lookup?q=<query>	Free-text service → SAC + rate

Sample request

cURL

curl -sS https://gstad.sahayakonline.co.in/v1/gst/ad/lookup?q=programmatic+display \
  -H "Authorization: Bearer $SAHAYAK_KEY" \
  -H "Accept: application/json"

Python

import os, requests
resp = requests.get(
    "https://gstad.sahayakonline.co.in/v1/gst/ad/lookup?q=programmatic+display",
    headers={"Authorization": f"Bearer {os.environ['SAHAYAK_KEY']}", "Accept": "application/json"},
    timeout=10,
)
resp.raise_for_status()
print(resp.json())

Node.js

const fetch = (await import('node-fetch')).default;
const resp = await fetch('https://gstad.sahayakonline.co.in/v1/gst/ad/lookup?q=programmatic+display', {
  headers: {
    'Authorization': `Bearer ${process.env.SAHAYAK_KEY}`,
    'Accept': 'application/json',
  },
});
console.log(await resp.json());

Sample response

{
  "spec_ref": "spec_11_GST_on_Advertising_Services_API",
  "endpoint": "/v1/gst/ad/lookup",
  "method": "GET",
  "results": [
    {
      "sac": "998365",
      "description": "Sale of internet advertising space (programmatic, display, video)",
      "rate_pct": 18,
      "place_of_supply_rule": "location of recipient (B2B); location of service provider (B2C)"
    }
  ],
  "meta": { "fixture_mode": false, "url": "https://gstad.sahayakonline.co.in/v1/" }
}

Error codes

Code	Meaning	Recommended action
400	Malformed request (missing required param, invalid format)	Fix request shape. Response body includes error.field pinpointing the issue.
401	Missing or invalid Authorization header	Verify key prefix matches your tier and that the header is Authorization: Bearer ….
403	Key valid but not entitled to this endpoint	Sandbox keys cannot call live-tier endpoints. Upgrade or request entitlement.
404	Resource not found	Check identifier format. Some endpoints return 200 with empty results[] instead of 404 — verify the endpoint convention.
429	Rate limit exceeded	Honor Retry-After header. Sandbox 30 r/m, Starter 300 r/m, Growth 1500 r/m.
503	Upstream regulator unreachable after retries	Live-tier only. Sahayak retries 3× with backoff before surfacing. Implement circuit-breaker on caller side.

Rate limits

Tier	Rate limit	Monthly cap
Sandbox	30 r/min	1,000 live calls (shared across 3 LIVE endpoints)
Starter	300 r/min	10,000 live calls
Growth	1,500 r/min	100,000 live calls
Scale	custom	500,000+

SLA reference

See Status & SLA for uptime targets, latency targets, and incident communication. Rate changes land within 24 hours of CBIC notification.