Cancel Subscription

Overview

The DELETE /subscription endpoint cancels one or more active subscriptions for a user. The cancellation is processed on-chain via the smart contract wallet system.

How It Works

Signature Verification: Request must include valid HMAC-SHA256 signature proving it comes from your authorized app
Ownership Check: Only subscriptions owned by the requesting user can be cancelled
On-Chain Execution: Subscription streams are closed via smart contract interaction
Gas Fee Handling: Gas fees are automatically estimated and added (with 10% safety markup)

Request Parameters

Headers

Header	Required	Description
`X-utilsio-Signature`	Conditional	HMAC-SHA256 signature. Required unless using Safari fallback flow (see below)
`X-utilsio-Timestamp`	Conditional	Unix timestamp in seconds. Required unless using Safari fallback flow

Body

Field	Type	Required	Description
`userId`	string	Yes	User ID who owns the subscription
`deviceId`	string	Conditional	Device ID. Optional if using Safari fallback - will be read from cookies
`appId`	string	Yes	Your application ID
`subscriptionIds`	string[]	Yes	Array of subscription IDs to cancel
`signatureCallbackUrl`	string	Conditional	Required for Safari fallback when signature headers are not provided. URL to your `/api/signature-callback` endpoint

Signature Generation

Normal Flow (Client-Side)

When deviceId is available (Chrome, Firefox, etc.), generate the signature client-side:

import { deriveAppHashHex, signRequest, nowUnixSeconds } from '@utilsio/react/server';

// Derive key (do this once at startup)
const appHashHex = deriveAppHashHex({
  appSecret: process.env.UTILSIO_APP_SECRET!,
  salt: process.env.UTILSIO_APP_SALT!,
});

// Sign the request
const timestamp = nowUnixSeconds();
const additionalData = subscriptionIds.sort().join(','); // Include subscription IDs in signature

const signature = signRequest({
  appHashHex,
  deviceId,
  appId: process.env.NEXT_PUBLIC_UTILSIO_APP_ID!,
  timestamp,
  additionalData, // IMPORTANT: Include this for DELETE requests
});

Safari Fallback Flow (Server-Side)

In Safari, third-party cookies are blocked so deviceId is not available client-side. Instead:

Client makes DELETE request without deviceId or signature headers
Include signatureCallbackUrl in request body
Server reads deviceId from first-party cookies
Server makes callback to your /api/signature-callback endpoint
Your endpoint generates and returns signature
Server verifies signature and processes deletion

Your callback endpoint (/api/signature-callback):

export async function POST(req: NextRequest) {
  const { deviceId, appId, additionalData, timestamp } = await req.json();

  const signature = signRequest({
    appHashHex,
    deviceId,
    appId,
    timestamp,
    additionalData, // subscriptionIds sorted and joined
  });

  return NextResponse.json({ signature, timestamp });
}

Security: For DELETE requests, you MUST include sorted subscriptionIds (comma-separated) as additionalData in the signature to prevent tampering.

Example Request

curl -X DELETE 'https://utilsio.dev/api/v1/subscription' \
  -H 'Content-Type: application/json' \
  -H 'X-utilsio-Signature: abc123...' \
  -H 'X-utilsio-Timestamp: 1705334400' \
  -d '{
    "userId": "user_123",
    "deviceId": "device_abc",
    "appId": "app_xyz",
    "subscriptionIds": ["sub_abc123"]
  }'

Response

Success (200)

{
  "success": true
}

Error Responses

Status	Error	Cause
400	`userId, appId, and subscriptionIds are required`	Missing required fields
400	`Device ID not found. Please ensure cookies are enabled.`	Safari flow failed to read deviceId from cookies
400	`signatureCallbackUrl is required when signature is not provided`	Safari flow missing callback URL
400	`User wallet not configured`	User hasn’t set up their wallet
401	`Invalid signature`	Signature verification failed
403	`Some subscriptions not found or unauthorized`	User doesn’t own all specified subscriptions
404	`No valid subscriptions found to delete`	None of the provided IDs exist
500	`Failed to obtain signature from app`	Safari flow: callback to app failed
500	`Failed to delete subscription stream`	On-chain transaction failed

Gas Fees

Gas fees are automatically handled:

Estimated based on current network conditions
10% safety markup added to prevent failures
Deducted from user’s wallet balance
No manual gas fee calculation required

Using the SDK

The React SDK handles all complexity for you:

'use client';
import { useUtilsio } from '@utilsio/react/client';

export default function ManageSubscription() {
  const { user, deviceId, currentSubscription, cancelSubscription } = useUtilsio();

  const handleCancel = async () => {
    if (!currentSubscription) return;
    if (!confirm('Are you sure you want to cancel your subscription?')) return;

    try {
      await cancelSubscription([currentSubscription.id]);
      // refresh() is called automatically, component re-renders
    } catch (err) {
      console.error('Cancellation failed:', err);
    }
  };

  return currentSubscription ? (
    <button onClick={handleCancel}>
      Cancel Subscription
    </button>
  ) : null;
}

Notes

Cancellations are immediate and irreversible
Users can re-subscribe at any time
On-chain confirmation may take a few seconds
Consider showing a loading state during cancellation
The SDK’s cancelSubscription() automatically refreshes subscription state after success

Authorizations

X-utilsio-Signature

string

header

required

Headers

X-utilsio-Signature

string

required

HMAC signature for request authentication

X-utilsio-Timestamp

string

required

Unix timestamp for request signing

Body

application/json

userId

string

required

The user ID who owns the subscription

deviceId

string

required

The device ID that initiated the subscription

appId

string

required

The application ID of the subscription

subscriptionIds

string[]

required

Array of subscription IDs to cancel

Unique identifier for a subscription

Response

Subscriptions cancelled successfully.

success

boolean

Whether the cancellation was successful

error

string

Error message if the cancellation failed

Subscriptions

Documentation Index

​Overview

​How It Works

​Request Parameters

​Headers

​Body

​Signature Generation

​Normal Flow (Client-Side)

​Safari Fallback Flow (Server-Side)

​Example Request

​Response

​Success (200)

​Error Responses

​Gas Fees

​Using the SDK

​Notes

Authorizations

Headers

Body

Response

Overview

How It Works

Request Parameters

Headers

Body

Signature Generation

Normal Flow (Client-Side)

Safari Fallback Flow (Server-Side)

Example Request

Response

Success (200)

Error Responses

Gas Fees

Using the SDK

Notes