SuprSend supports three authentication methods:
  • Workspace Key & Secret → Used to authenticate requests from Backend SDKs.
  • API Keys → Used to authenticate REST APIs as Bearer <API_KEY>.
  • Public Key & Signing Key → Used to authenticate Client SDKs (with enhanced security options).
All keys and secrets are unique per workspace. This is done to keep your testing and production workspace separate and safeguards against accidentally sending wrong notification to your production users during testing.

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1. Authenticating Backend SDKs

Backend SDKs are authenticated using a Workspace Key and Workspace Secret. To find these credentials:
  1. Go to SuprSend Dashboard → Developers → API Keys.
  2. The Workspace Key and Secret for the selected workspace are shown at the top.
Save this as environment variable in your backend SDK configuration for safekeeping.

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2. Authenticating REST API Requests

REST API requests are authenticated using API Keys. Pass the API Key in the Authorization header with Bearer scheme: 
Authorization: Bearer <API_KEY>
Content-Type: application/json
To find these credentials:
  1. Navigate to Dashboard → Developers → API Keys.
  2. Click Generate API Key.
  3. Provide a name and select Create and Save.
  4. Copy the API Key and store it securely — it will be shown only once at generation.
API Keys are confidential and are shown only once at generation. We recommend keeping them in your environment variables or secure vault to avoid accidental exposure.

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3. Authenticating Client-side SDKs

Client SDKs (Web/Mobile) use Public Keys for authentication. You can manage these in Dashboard → Developers → API Keys → Public Keys. Generate new keys or rotate/delete existing ones. For Production workspaces, Public Keys alone are insecure. Enable Enhanced Security Mode, which requires a Signed User Token (JWT) from your backend.
📘 Some legacy mobile SDKs may still use Workspace Key/Secret. These are being phased out.

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Enhanced Security Mode with signed User Token

When enhanced security mode is on, user level authentication is performed for all requests. This is recommended for Production workspaces. All requests will be rejected by SuprSend if enhanced security mode is on and signed user token is not provided. This signed user token should be generated by your backend application and should be passed to your client.
1

Generate Signing Key

You can generate Signing key from SuprSend Dashboard (below Public Keys section in API Keys page).Once signing key is generated it won’t be shown again, so copy and store it securely. It contains 2 formats:
  • Base64 format: This is single line text, suitable for storing as an environment variable.
  • PEM format: This is multiline text format string.
You can use any of the above format. This key will be used as secret to generate JWT token as shown in below step.
2

Creating Signed User JWT Token

This should be created on your backend application only. You will need to sign the JWT token with the signing key from above step and expose this JWT token to your Frontend application.
  • JWT Algorithm:ES256
  • JWT Secret:Signing key in PEM format generated in step1. If you are using Base64 format, it should be converted in to PEM format.
  • JWT Payload: 
{
  "entity_type": 'subscriber', // hardcode this value to subscriber
  "entity_id": your_distinct_id, // replace this with your actual distinct id
  "exp": 1725814228, // token expiry timestamp in seconds
  "iat": 1725814228 // token issued timestamp in seconds.
  "scope": { "tenant_id": "string" }
}
SuprSend requests will be scoped to tenant. If tenant passed by you in SDK doesn’t match with the JWT payload scope tenant_id then requests will throw 403 error.If tenant_id is not passed, it is assumed to be default tenant.Currently only Inbox requests supports scope, later on we will extend it to preferences and other requests.
Create JWT token using above information:
import jwt from 'jsonwebtoken';

const payload  = { entity_type:'subscriber', entity_id:"johndoe", exp:1725814228 };

const secret = 'your PEM format signing key';

// if base64 signing key format is used use below code to convert to PEM format.
const secret = Buffer.from('your_base64_signingKey', 'base64').toString('utf-8')

const signedUserToken = jwt.sign(payload, secret,{ algorithm: 'ES256' })
3

Using signed user token in client

After creating user token on backend send it to your Frontend application to be used in SuprSend SDK as user token.
import SuprSend from '@suprsend/web-sdk';

const suprSendClient = new SuprSend(publicApiKey: string);

const authResponse = await suprSendClient.identify(user.id, user.userToken);

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Token expiry handling

To handle cases of token expiry our client SDK’s have Refresh User Token callback as parameter in identify method which gets called to get new user token when existing token is expired. 
const authResponse = await suprSendClient.identify(user.id, user.userToken,
  { refreshUserToken: (oldUserToken, tokenPayload) => {
     //.... write your logic to get new token by making API call to your server...
     // return new token
  }});