Payment

Vantack API

Introduction

Authentication

Generating API Keys

<p class="slate-p " >Accounts are the basic organizations that use Coinsub services. They can be individuals, businesses, or non-profit organizations. They can have one or more users associated with them, and they can be connected to other accounts. </p><p class="slate-p slate-indent-0" style="0px">Creating an account through the API will connect that account with your account, enabling you to call the API as that account in the future. This allows a platform account the ability to onboard users, and configure products, and payment agreements for their users. </p><p class="slate-p " ></p>

Accounts & API Keys

<p class="slate-p " >As a platform merchant, you can create accounts for your users (submerchants). </p><p class="slate-p " >If you’ve already collected information for your connected accounts, you set that information here.  We won’t ask for the prefilled information during account onboarding. You can prefill any information on the account. Creating connected accounts in this way allows you to call endpoints as that account, to perform actions for your users. </p><p class="slate-p " >Additionally, if you need to setup a wallet address for your users, you can send it in the <code class="slate-code">default_deposit_address</code> parameter of the request body. Alternativelly, you can leave it empty and the user will be guided to creating their own wallet when they sign up. </p><p class="slate-p " >For submitting the additional metadata about the user, below are the accepted values per input (<strong class="slate-bold">optional</strong>):</p><h4 class="slate-h4 " >Industry</h4><div class="code-block-wrapper"  style="width:100%" ><div class="code-block-header">Plain text</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden">software
financial_services
ecommerce
healthcare
education
blockchain_crypto
artificial_intelligence
cybersecurity
cloud_services
media_entertainment
gaming
telecommunications
retail
logistics
real_estate
insurance
legal_services
marketing_advertising
human_resources
energy_utilities
biotechnology
manufacturing
construction
agriculture
hospitality_tourism
transportation
non_profit
government
other </textarea><code class="language-plainText keep-markup drop-tokens"></code></pre></div><h4 class="slate-h4 " >UserRole</h4><div class="code-block-wrapper"  style="width:100%" ><div class="code-block-header">Plain text</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden">founder
ceo
cto
cfo
coo
vp_engineering
vp_product
vp_sales
vp_marketing
vp_operations
vp_finance
engineering_manager
product_manager
sales_manager
marketing_manager
operations_manager
senior_developer
developer
data_scientist
devops_engineer
product_owner
business_analyst
other </textarea><code class="language-plainText keep-markup drop-tokens"></code></pre></div><div class="slate-div"></div><h4 class="slate-h4 " >CompanySize</h4><div class="code-block-wrapper"  style="width:100%" ><div class="code-block-header">Plain text</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden">1_10
11_50
51_200
201_500
501_1000
1001_5000
5001_10000
10000_plus </textarea><code class="language-plainText keep-markup drop-tokens"></code></pre></div><h4 class="slate-h4 " >UseCase</h4><div class="code-block-wrapper"  style="width:100%" ><div class="code-block-header">Plain text</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden">subscriptions
one_time_payments
api_integration
marketplace
donations
crowdfunding
content_monetization
gaming_payments
other </textarea><code class="language-plainText keep-markup drop-tokens"></code></pre></div><p class="slate-p " ></p>

Create an account

<p class="slate-p " >Resends the verification email to the user (submerchant) if it was not received. This endpoint has a 20-minute cooldown period between requests.</p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Resend Verification Email

<p class="slate-p " >With Coinsub, you can update connected user/merchant accounts. To update your own account use the Coinsub dashboard. </p><p class="slate-p " >Notes:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Email field cannot be updated</div></li><li class="slate-li " ><div style="position:relative">The request will fail if wallet address already exists in the system
</div></li></ul><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Update an account

<p class="slate-p slate-indent-0" style="0px">Retrieves the details of a connected user/merchant account.
</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve an account

<p class="slate-p slate-indent-0" style="0px">Retrieves a list of connected accounts.
</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

List all connected accounts

<p class="slate-p slate-indent-0" style="0px">Creates an API Key for the connected account</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Create API Key for connected account

<p class="slate-p slate-indent-0" style="0px">Retrieves all API Keys for the connected account</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve API Keys for connected account

<p class="slate-p slate-indent-0" style="0px">Disables an API Key for the connected account</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Disable API Key for connected account

<p class="slate-p slate-indent-0" style="0px">Delete a connected account. Accounts with ongoing payment agreements can&apos;t be deleted until all payment agreements are deleted. 
</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Delete an account

<p class="slate-p " >Coinsub Merchant Wallets are secure, non-custodial wallets powered by <a href="https://www.dfns.co/" target="_self">DFNS’s</a> battle-tested wallet infrastructure. Designed with robust key management and WebAuthn-based authentication, these wallets ensure enterprise-grade security without exposing private keys or relying on vulnerable seed phrases. With Merchant Wallets, Coinsub merchants don’t need to connect external wallets or manage third-party integrations. Everything is built-in—making on-chain payments, managing funds, and receiving crypto subscriptions frictionless and secure, straight from your Coinsub dashboard.</p><p class="slate-p " >To get started with a merchant platform wallet of your own, sign up at <a href="https://test.coinsub.io" target="">test.coinsub.io</a> (development environment) or <a href="https://app.coinsub.io" target="">app.coinsub.io</a> (production).</p><p class="slate-p " >Signing up on the platform will get you a merchant wallet and setup your initial default passkey. If you&apos;re interested you can take a look at a short video below. </p><p class="slate-p " ></p><div class="iframe-embed"><iframe
                        title="embed"
                        frameBorder="0"
                        allowFullScreen=""
                        src="https://www.youtube.com/embed/fMUpygfdrrY"
                        id="fMUpygfdrrY"
                        provider="youtube"
                        class="slate-MediaEmbedElement-iframe"
                        width="100%"
                    ></iframe></div><p class="slate-p " ></p><p class="slate-p " ></p>

Merchant Wallet

<p class="slate-p " >Merchant wallets on our platform support two types of credentials:</p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">FIDO2 / Passkeys</strong>
FIDO2 credentials (commonly referred to as passkeys) offer a secure, passwordless authentication method based on public key cryptography. These credentials are typically linked to a user and stored in secure authenticators (e.g., platform authenticators like Face ID, or external security keys). Upon sign up, a default passkey will be added to your Coinsub account. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Key Credentials (Raw Key Pairs)</strong>
This credential type allows you to register and use your own asymmetric key pairs (e.g., ECDSA or RSA). These keys are not tied to a user identity and can be stored and used programmatically—for example, in secure backend services or HSMs. </div></li></ol><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Remote Signing via API Credentials</h3><p class="slate-p " >If you&apos;re integrating with our platform programmatically (e.g., to initiate or approve wallet actions from a backend service), you can attach additional key credentials to your merchant wallet. This enables cryptographic signing of wallet operations <strong class="slate-bold">without requiring user login or passkey interaction</strong>.</p><p class="slate-p " >To do this:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Generate a key pair (ECDSA or RSA). </div></li><li class="slate-li " ><div style="position:relative">Register the public key via our API to create a new credential. </div></li><li class="slate-li " ><div style="position:relative">Use the corresponding private key in your remote service to sign requests. </div></li></ul><p class="slate-p " >This allows you to maintain secure, non-interactive access to wallet features while preserving the integrity of the signature flow.</p><div class="slate-div"><p class="slate-p " ><strong class="slate-bold">Note:</strong> You can associate multiple credentials with a merchant wallet, including both passkeys and key credentials, enabling flexibility for both user-interactive and backend-driven operations.</p></div><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Creating a Key Credential</h3><p class="slate-p " >In order to create a new Key Credential you can use the sample code provided in this GitHub Repository. The <a href="https://github.com/CoinSub/public/blob/d1aef044e62f1eeb9584ba8114b4c51a7c9aa39c/src/keyManager.ts#L7" target="_self">getOrCreateKeyPair</a> function will create a new keypair and store it locally, or read one from the file system if it&apos;s already created. Alternativelly, you can generate keys using tools like OpenSSL, or programmatically in your language of choice. Here&apos;s an example using OpenSSL to generate an ECDSA key pair:</p><div class="code-block-wrapper"  style="width:100%;min-width:100%" ><div class="code-block-header">Bash</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden"> </textarea><code class="language-bash keep-markup drop-tokens"><div class="slate-code_line"><div class="slate-code_line">Generate private key (P-256 curve)</div><div class="slate-code_line">openssl ecparam -name prime256v1 -genkey -noout -out private_key.pem</div><div class="slate-code_line"></div><div class="slate-code_line">Extract the public key</div><div class="slate-code_line">openssl ec -in private_key.pem -pubout -out public_key.pem</div></div></code></pre></div><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " >The rest of the flow will walk you through the platform APIs to create a new Key credential in our system. All of the endpoints and steps needed to create and add a Key Credential to your merchant account are described in these 2 videos below. </p><h4 class="slate-h4 " >Steps 1 and 2</h4><p class="slate-p " ></p><div class="iframe-embed"><iframe
                        title="embed"
                        frameBorder="0"
                        allowFullScreen=""
                        src="https://www.youtube.com/embed/EiK24salyjU"
                        id="EiK24salyjU"
                        provider="youtube"
                        class="slate-MediaEmbedElement-iframe"
                        width="100%"
                    ></iframe></div><p class="slate-p " ></p><h4 class="slate-h4 " >Steps 3 and 4</h4><p class="slate-p " ></p><div class="iframe-embed"><iframe
                        title="embed"
                        frameBorder="0"
                        allowFullScreen=""
                        src="https://www.youtube.com/embed/lLTAKRxfHXM"
                        id="lLTAKRxfHXM"
                        provider="youtube"
                        class="slate-MediaEmbedElement-iframe"
                        width="100%"
                    ></iframe></div><p class="slate-p " ></p><p class="slate-p " ></p>

Wallet Credentials

<p class="slate-p " >Traditionally, sending crypto funds requires users to pay <em class="slate-italic">gas fees</em> using the native token of the blockchain they&apos;re operating on — for example, ETH on Ethereum or MATIC (POL) on Polygon. This can be a barrier, especially for users who don’t already hold these tokens.</p><p class="slate-p " >To improve the user experience, we’ve introduced <strong class="slate-bold">gasless transfers</strong> — a simple and seamless way to send funds without needing to hold or spend native tokens. This makes transactions faster, easier, and more accessible for all users.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >How Gasless Transfers Work</h3><p class="slate-p " >Gasless transfers on our platform can be executed in two different ways:</p><h4 class="slate-h4 " >1. Platform-Signed Transfers</h4><p class="slate-p " >In this mode, the <strong class="slate-bold">Platform handles the transaction signature on behalf of the Merchant</strong>.</p><p class="slate-p " >The Merchant grants the Platform permission to sign transfers up to a specified threshold (e.g. $100 per transfer). If a transfer exceeds this threshold, the Platform will request a manual signature from the Merchant before proceeding.</p><p class="slate-p " >This setup is ideal for minimizing operational friction while maintaining control over large or sensitive transfers.</p><h4 class="slate-h4 " >2. Merchant-Signed Transfers</h4><p class="slate-p " >Alternatively, the <strong class="slate-bold">Merchant can handle the signing process directly</strong>, maintaining full control over every transaction.</p><p class="slate-p " >In this case, each transfer must be individually approved and signed by the Merchant&apos;s system, typically via a connected private key or WebAuthn device.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Security Restrictions</h3><p class="slate-p " >To protect users from potential abuse or unauthorized activity, <strong class="slate-bold">gasless transfers are only permitted between wallets registered within our system</strong>. This ensures traceability, accountability, and reduces the risk of fraud or phishing attempts.</p><p class="slate-p " ></p><p class="slate-p " ></p>

Wallet Transfers

<p class="slate-p " >This section outlines a set of API endpoints designed to retrieve information related to wallets, including wallet details, associated assets, and transaction history.</p><p class="slate-p " ></p>

Wallet Information

<p class="slate-p " >At <strong class="slate-bold">Coinsub</strong>, a <strong class="slate-bold">product</strong> is a digital offer created by a merchant that users can purchase in exchange for access to a service, benefit, or digital experience. While many products are traditional subscriptions, they can also represent <strong class="slate-bold">one-time access</strong> or <strong class="slate-bold">single-purchase offerings</strong>.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Core Aspects of a Coinsub Product:</h3><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Merchant-Defined</strong>:
 Each product is owned and managed by a specific merchant, who determines its pricing, duration, and usage. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Descriptive Name</strong>:
 Every product has a clear and user-friendly title that communicates what the offering is. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Flexible Pricing Model</strong>:
 Products are priced in U.S. dollars, but payment may be made using crypto. The pricing supports both <strong class="slate-bold">recurring subscriptions</strong> and <strong class="slate-bold">one-time purchases</strong>. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Blockchain Integration</strong>:
 Payments are directed to a dedicated blockchain address, enabling secure, on-chain transactions. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Lifecycle Status</strong>:
 Products can be marked as active (available for purchase), inactive (temporarily paused), or discontinued (retired), giving merchants control over their offerings. </div></li></ul><p class="slate-p " ></p>

Subscription Products

<p class="slate-p " >List all products for your merchant account.</p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve all Subscription Products

<p class="slate-p " >List all active subscriptions for a subscriber.</p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve Subscriptions For Subscriber

<p class="slate-p " >List all active subscriptions for a subscriber.</p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve Subscriptions For Subscriber and Product Id

<p class="slate-p " >This endpoint checks the subscription status of a subscriber based on metadata. It returns one of three responses: active subscription, inactive subscription, or no matching subscription.</p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Retrieve the Subscription Status of a Product with a Subscriber’s Metadata

Agreements

Cancel an Agreement

Retrieve an agreement

Retrieve all agreements

Payments

Retrieve a payment

Retrieve all payments

Purchase Sessions

Create A Purchase Session

Retrieve Purchase Session Status

Delete Purchase Session 

<p class="slate-p " >Force expires a specific purchase session.</p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Expire Purchase Session

Purchase Messages

Request Purchase Message to Sign

Submit Signed Purchase Message

Permit Messages

Submit Signed Permit Message

<p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">This comprehensive guide provides detailed information about integrating Coinsub payment processing into your application. Coinsub offers four distinct integration methods designed to accommodate different technical requirements and use cases, from simple no-code solutions to advanced API integrations with full customization capabilities.</span></p><p class="slate-p " ></p><div class="table-container" style="width:100%;
  min-width:100%;"><table class="slate-table" style="min-width:100%"><div class="published-table-header" style="width:100%;min-width:100%;"><div style="width:100px;">Option</div><div style="width:100px;">Integration Level</div><div style="width:100px;">Customization</div><div style="width:100px;">Hosted Checkout UI</div></div><colgroup ><col style="width:initial"><col style="width:initial"><col style="width:initial"><col style="width:initial"></colgroup><tbody class="slate-TableElement-tbody"><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">1. Standard Checkout Link</span></p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">🔹 No Code</span></p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">✅ (full control)</span></p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">✅</span></p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >2. Button Embed</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Low Code</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (button color)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅</p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >3. iFrame Embed</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Medium Code</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (full control)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅</p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >4. Headless API</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Developer</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (fully programmable)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >❌</p></td></div></tr></tbody></table></div><p class="slate-p " ></p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h2 class="slate-h2 " >Which Integration Option Should You Use?</h2><p class="slate-p " >Choosing the right integration depends on your <strong class="slate-bold">technical resources</strong>, <strong class="slate-bold">business model</strong>, and <strong class="slate-bold">how much control</strong> you want over the checkout experience.</p><h3 class="slate-h3 " ><span style="color:rgb(0, 0, 0)">🔹 </span>Standard Checkout Link – Best for Non-Technical Merchants</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Individual creators</div></li><li class="slate-li " ><div style="position:relative">Small merchants or service providers</div></li><li class="slate-li " ><div style="position:relative">Teams with no dev resources</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Zero development required</div></li><li class="slate-li " ><div style="position:relative">Shareable across any platform (email, social, website)</div></li><li class="slate-li " ><div style="position:relative">Fastest way to start accepting stablecoin payments</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Button Embed – Best for Low-Code Teams</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Marketing teams with light dev help</div></li><li class="slate-li " ><div style="position:relative">Shopify, WordPress, or Webflow users</div></li><li class="slate-li " ><div style="position:relative">Sites that need a call-to-action button with minimal backend setup</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Simple HTML embed</div></li><li class="slate-li " ><div style="position:relative">Button styling via <code class="slate-code">data-color</code></div></li><li class="slate-li " ><div style="position:relative">Redirects to secure hosted checkout</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Modal iFrame – Best for Custom Frontends That Want In-Site UX</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Sites with web developers</div></li><li class="slate-li " ><div style="position:relative">Businesses that care about seamless branding and user experience</div></li><li class="slate-li " ><div style="position:relative">Publishers, SaaS sites, or gated content platforms</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Fully embedded experience</div></li><li class="slate-li " ><div style="position:relative">Controlled modal styling</div></li><li class="slate-li " ><div style="position:relative">Checkout stays within your UI context</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Headless API – Best for Crypto-Native Platforms &amp; Advanced Teams</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Web3 apps, dApps, DeFi platforms</div></li><li class="slate-li " ><div style="position:relative">Teams already managing wallets or signing flows</div></li><li class="slate-li " ><div style="position:relative">Platforms needing custom onboarding, wallet UX, or nonstandard product logic</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Full control over the payment process</div></li><li class="slate-li " ><div style="position:relative">You manage wallet interaction and signing</div></li><li class="slate-li " ><div style="position:relative">Suitable for integrations with other on-chain or backend systems</div></li></ul><p class="slate-p " ></p><p class="slate-p " ></p>

Integration Options

<p class="slate-p " >Before using any integration option, follow these steps to create a product and get its unique checkout link:</p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Visit the Merchant Dashboard</strong>
 <a href="https://test.coinsub.io/merchant/products/" target="_new">https://test.coinsub.io/merchant/products/</a></div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Click “+ Add Product”</strong>
Fill in the product name, pricing, and other details. You can create one-time or recurring subscription products. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Get Your Product Link &amp; ID</strong>
After creation, you’ll be shown a <strong class="slate-bold">unique product checkout link</strong>, like: <a href="https://test-buy.coinsub.io/9d205d5012" target="_self">https://test-buy.coinsub.io/9d205d5012</a>
This ID (9d205d5012) is your product identifier, and it&apos;s used in embed code, API requests, and iframe integrations.</div></li></ol><p class="slate-p " >Now, let’s look at how you can integrate Coinsub with your site or product.</p><p class="slate-p " ></p>

Create a Product

<p class="slate-p " ><span style="color:var(--tw-prose-bold)"><strong class="slate-bold">Best for:</strong></span><span style="color:oklch(0.3039 0.04 213.68)"> Merchants who need to start accepting payments immediately without any technical implementation</span></p><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">This is the simplest way to accept payments with Coinsub. No coding knowledge is required - merchants simply create products through the merchant dashboard and share checkout links with customers.</span></p><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Implementation Steps:</span></h2><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Create a product</strong></span><span style="color:oklch(0.3039 0.04 213.68)"> on the merchant dashboard</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Configure payment settings and preferences</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Get your checkout link, </strong></span><span style="color:oklch(0.3039 0.04 213.68)">example</span><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">:</strong></span><span style="color:oklch(0.3039 0.04 213.68)"> </span><a href="https://test-buy.coinsub.io/9d205d5012" target="_self"><span style="color:oklch(0.3039 0.04 213.68)">https://test-buy.coinsub.io/9d205d5012</span></a></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Share the link </strong></span><span style="color:oklch(0.3039 0.04 213.68)">(send the link to customers via email, SMS, or social media or embed the link in your website, app, or marketing materials)</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Customers click the link to access the Coinsub checkout UI</span></div></li></ol><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Customer Experience:</span></h2><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Customers are redirected to the secure Coinsub checkout page</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Full payment processing with stablecoin support</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Automatic order confirmation</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Mobile-optimized checkout experience</span></div></li></ul><p class="slate-p " ></p>

Standard Checkout Link

<p class="slate-p " ><span style="color:var(--tw-prose-bold)"><strong class="slate-bold">Best for:</strong></span><span style="color:oklch(0.3039 0.04 213.68)"> Websites and applications that want seamless payment buttons with minimal development effort</span></p><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">This method allows you to embed customizable payment buttons directly into your website with just a single script tag.</span></p><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">Look:</span></p><div style="text-align:left"><img src="https://d24lr4zqs1tgqh.cloudfront.net/39059c7a-257d-4175-8cbb-23331b558fa7.jpg" style="width:auto;height:auto" /></div><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Prerequisites:</span></h2><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">A product created via the merchant dashboard</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Basic HTML/JavaScript knowledge for customization</span></div></li></ul><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Implementation:</span></h2><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">After creating your product, you&apos;ll receive an HTML code snippet:</span></p><div class="code-block-wrapper"  style="width:60%" ><div class="code-block-header">HTML</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden"><script class="crypto-button-script" data-id="9d205d5012" data-color="#0484fc" src="https://test-buy.coinsub.io/djs/button.js"></script> </textarea><code class="language-html keep-markup drop-tokens"></code></pre></div><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">After receiving the snippet, you can embed it as shown in this </span><a href="https://codesandbox.io/p/sandbox/button-embed-m5gthv" target=""><span style="color:oklch(0.3039 0.04 213.68)">Demo project&apos;s</span></a><span style="color:oklch(0.3039 0.04 213.68)"> </span><a href="index.html" target="_self"><span style="color:oklch(0.3039 0.04 213.68)">index.html</span></a> <span style="color:oklch(0.3039 0.04 213.68)">with various changes to button attributes for your brand.</span></p><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Customization Options:</span></h2><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Button Color</strong></span><span style="color:oklch(0.3039 0.04 213.68)">: Modify the </span><span style="background-color:oklch(var(--background-color-200));color:oklch(0.3039 0.04 213.68)"><code class="slate-code">data-color</code></span><span style="color:oklch(0.3039 0.04 213.68)"> attribute to match your brand</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Button Size</strong></span><span style="color:oklch(0.3039 0.04 213.68)">: Additional sizing options available in the button library</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Custom CSS</strong></span><span style="color:oklch(0.3039 0.04 213.68)">: Apply additional styling to integrate with your design syste</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)"><strong class="slate-bold">Product Id</strong></span><span style="color:oklch(0.3039 0.04 213.68)">: Modify the </span><span style="background-color:oklch(var(--background-color-200));color:oklch(0.3039 0.04 213.68)"><code class="slate-code">data-id</code></span><span style="color:oklch(0.3039 0.04 213.68)"> attribute to reuse for another product</span></div></li></ul><p class="slate-p " ></p>

Button Embed

<p class="slate-p " ><span style="color:var(--tw-prose-bold)"><strong class="slate-bold">Best for:</strong></span><span style="color:oklch(0.3039 0.04 213.68)"> Providing a seamless checkout experience while keeping customers on your website</span></p><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">This method embeds the checkout experience directly into your website using an iframe within a modal overlay, ensuring customers never leave your site during the payment process.</span></p><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">Look: </span></p><p class="slate-p " ></p><div style="text-align:left"><img src="https://d24lr4zqs1tgqh.cloudfront.net/60cf256b-28c1-490c-86fa-1631b6113385.jpg" style="
              width:1296px;
	            height:2042px;
	            aspect-ratio:1296 / 2042"
         /></div><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Prerequisites:</span></h2><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">A product created via the merchant dashboard</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">Basic HTML/JavaScript knowledge for customization</span></div></li></ul><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Implementation:</span></h2><p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">After creating your product, you should use your checkout link to generate the iframe code as follows: </span></p><div class="code-block-wrapper"  style="width:100%;min-width:100%" ><div class="code-block-header">HTML</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden"><iframe
          src="https://test-buy.coinsub.io/9d205d5012"
          allow="clipboard-read *; publickey-credentials-create *; publickey-credentials-get *"
        ></iframe> </textarea><code class="language-html keep-markup drop-tokens"></code></pre></div><p class="slate-p " >Y<span style="color:oklch(0.3039 0.04 213.68)">ou can embed it as shown in this </span><a href="https://codesandbox.io/p/sandbox/iframe-embed-qm5rz4" target="_self"><span style="color:oklch(0.3039 0.04 213.68)">Demo project&apos;s</span></a><span style="color:oklch(0.3039 0.04 213.68)"> index.html</span> <span style="color:oklch(0.3039 0.04 213.68)">file.</span> </p><h2 class="slate-h2 " ><span style="color:oklch(0.3039 0.04 213.68)">Security Considerations:</span></h2><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">The iframe includes necessary permissions for secure crypto payments</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">All payment processing occurs within the Coinsub secure environment</span></div></li><li class="slate-li " ><div style="position:relative"><span style="color:oklch(0.3039 0.04 213.68)">No sensitive payment data is handled by your website</span></div></li></ul><p class="slate-p " ></p>

iFrame Embed

<p class="slate-p " ><strong class="slate-bold">Best for:</strong> Advanced integrations requiring full control over the payment flow, UI, and custom business logic.</p><p class="slate-p " >This method allows you to programmatically create purchase sessions via the platform’s API. You can then:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Use the returned checkout link with any of the standard integration methods, <strong class="slate-bold">or</strong></div></li><li class="slate-li " ><div style="position:relative">Build your own UI, implement custom signing flows, and handle blockchain transactions directly.</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Prerequisites</h3><p class="slate-p " >Before using the Headless API, ensure you have:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">An API key (see <a href="https://app.theneo.io/crypto-payment/api/coinsub-api/generating-api-keys" target="_self">how to create an API key</a>)</div></li><li class="slate-li " ><div style="position:relative">Familiarity with HTTP requests and handling JSON</div></li><li class="slate-li " ><div style="position:relative">Capability to manage wallet connections and signature flows (e.g., using MetaMask, WalletConnect)</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Summary</h3><p class="slate-p " >With the headless integration flow, the platform allows you to:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Create a purchase session per customer</div></li><li class="slate-li " ><div style="position:relative">Retrieve a typed data message (EIP-712) for signing the purchase message</div></li><li class="slate-li " ><div style="position:relative">Implement a custom UI for checkout that includes wallet connection + signing experience</div></li><li class="slate-li " ><div style="position:relative">Submit signed messages to Coinsub to initiate blockchain payment</div></li><li class="slate-li " ><div style="position:relative">Handle webhook events to track payment completion</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Flow: Step-by-Step</h3><h4 class="slate-h4 " >1. Create a Purchase Session</h4><p class="slate-p " ><strong class="slate-bold">POST</strong> to the platform’s API with product and buyer details (see<a href="https://app.theneo.io/crypto-payment/api/purchase-sessions/create-a-payment-request" target="_self"> how to create a purchase session</a>).
   Response includes a unique <code class="slate-code">purchase_session_id</code>.</p><h4 class="slate-h4 " >2. Request Message to Sign</h4><p class="slate-p " >Use the <code class="slate-code">purchase_session_id</code> as well as customer data to obtain a typed data message describing the purchase (see <a href="https://app.theneo.io/crypto-payment/api/purchase-messages/create-a-purchase-session-copy-1" target="_self">how to get message</a>)
   The response returns EIP-712 typed data for user signature.</p><h4 class="slate-h4 " >3. Handle Wallet &amp; Sign Message</h4><p class="slate-p " >Your frontend connects to the wallet (e.g., MetaMask).
   Prompt the user to sign the provided typed data and store the resulting signature (see <a href="https://codesandbox.io/p/sandbox/eip712-message-signing-2scgy6" target="_self">how to sign typed data</a>). </p><h4 class="slate-h4 " >4. Submit Signature</h4><p class="slate-p " ><strong class="slate-bold">POST</strong> the signature back to the platform using the <code class="slate-code">Submit Signer Purchase Message</code> <a href="https://app.theneo.io/crypto-payment/api/purchase-messages/request-purchase-message-to-sign-copy-3" target="_self">API endpoint</a>.
   The Coinsub platform processes and broadcasts the transaction on-chain.</p><h4 class="slate-h4 " >5. Listen for Webhook Events</h4><p class="slate-p " >Receive webhook notifications such as described in our <a href="https://app.theneo.io/crypto-payment/api/webhooks-3" target="_self">Webhooks section</a>. 
   Use these to unlock access, show success screens, or retry flows for your users. </p><p class="slate-p " ></p>

Headless API

<p class="slate-p " >Webhooks allow real-time communication between systems.</p><p class="slate-p " >Webhooks are used to synchronize disparate systems by publishing automated messages with predefined payloads that can be interpreted by integrated systems. They allow real-time communication between applications, enabling instant updates and data sharing without the need for continuous polling.</p><p class="slate-p " >Our platform webhooks provide notifications when specific actions occur on your account, such as when a customer subscribes to a product, purchases a one-off product, makes a payment, or cancels a subscription. By setting up webhooks, you can automate processes and keep your systems in sync with our platform in real-time.</p><p class="slate-p " ></p>

Webhooks

<div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Sign into the platform</strong></div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Navigate to Merchant Settings</strong></div><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">From the dashboard, select the Settings menu located on the sidebar, then merchant settings </div></li></ul></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Input Webhook URL</strong></div><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Input your webhook URL and other merchant details in the settings.</div></li></ul></li></ol><p class="slate-p " >If you are looking to control the webhook URLs configuration for your other connected merchant accounts, you can do so </p>

How to Use the Webhooks

<div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h4 class="slate-h4 " >The webhook is triggered during the following actions:</h4><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">When a customer subscribes to a product.</div></li><li class="slate-li " ><div style="position:relative">When a customer purchases a one-off product.</div></li><li class="slate-li " ><div style="position:relative">When a customer makes a payment.</div></li><li class="slate-li " ><div style="position:relative">When a customer cancels a subscription.</div></li><li class="slate-li " ><div style="position:relative">When you execute a wallet send transaction from your account</div></li></ul><p class="slate-p " ></p>

Webhook Triggers

Webhook Payloads

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<h2 class="slate-h2 " ><strong class="slate-bold">Advanced API Structure for Seamless Integration</strong></h2><p class="slate-p " >To enable third-party platforms to integrate Vantack&apos;s capabilities, we&apos;ve meticulously designed a comprehensive and flexible API structure. Our API facilitates easy integration, providing developers with the tools to incorporate blockchain payment solutions into their applications.</p><h3 class="slate-h3 " ><strong class="slate-bold">Core API Components</strong></h3><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Secure Authentication</strong>: Utilizing API keys we ensure secure and authorized access to our services.</div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Blockchain Interaction</strong>: Developers can easily select networks, manage tokens, and authorize transactions, offering unparalleled flexibility across blockchains.</div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Dynamic Payment Processing</strong>: Our API supports the creation and management of various payment types, including one-time invoices, recurring subscriptions, and usage-based billing, with built-in support for handling overdue payments.</div></li></ul><p class="slate-p " ></p><p class="slate-p " >

</p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Advanced API Structure for Seamless Integration

To enable third-party platforms to integrate Vantack's capabilities, we've meticulously designed a comprehensive and flexible API structure. Our API facilitates easy integration, providing developers with the tools to incorporate blockchain payment solutions into their applications.

Advanced API Structure for Seamless IntegrationTo enable third-party platforms to integrate Vantack's capabilities, we&apos;ve meticulously designed a

<p class="slate-p " >Accounts are the basic organizations that use Vantack services. They can be individuals, businesses, or non-profit organizations. They can have one or more users associated with them, and they can be connected to other accounts. </p><p class="slate-p slate-indent-0" style="0px">Creating an account through the API will connect that account with your account, enabling you to call the API as that account in the future. This allows a platform account the ability to onboard users, and configure products, and payment agreements for their users. </p><p class="slate-p " ></p><p class="slate-p " ></p>

Accounts are the basic organizations that use Vantack services. They can be individuals, businesses, or non-profit organizations. They can have one or more users associated with them, and they can be connected to other accounts. 

Creating an account through the API will connect that account with your account, enabling you to call the API as that account in the future. This allows a platform account the ability to onboard users, and configure products, and payment agreements for their users. 

<p class="slate-p " >Vantack Merchant Wallets are secure, non-custodial wallets powered by <a href="https://www.dfns.co/" target="_self">DFNS’s</a> battle-tested wallet infrastructure. Designed with robust key management and WebAuthn-based authentication, these wallets ensure enterprise-grade security without exposing private keys or relying on vulnerable seed phrases. With Merchant Wallets, Vantack merchants don’t need to connect external wallets or manage third-party integrations. Everything is built-in—making on-chain payments, managing funds, and receiving crypto subscriptions frictionless and secure, straight from your Vantack dashboard.</p><p class="slate-p " >To get started with a merchant platform wallet of your own, sign up at <a href="https://test.vantack.com" target="">test.vantack.com</a> (development environment) or <a href="https://app.vantack.com" target="">app.vantack.com</a> (production).</p><p class="slate-p " >Signing up on the platform will get you a merchant wallet and setup your initial default passkey.</p><p class="slate-p " ></p><p class="slate-p " ></p>

Vantack Merchant Wallets are secure, non-custodial wallets powered by 

 battle-tested wallet infrastructure. Designed with robust key management and WebAuthn-based authentication, these wallets ensure enterprise-grade security without exposing private keys or relying on vulnerable seed phrases. With Merchant Wallets, Vantack merchants don’t need to connect external wallets or manage third-party integrations. Everything is built-in—making on-chain payments, managing funds, and receiving crypto subscriptions frictionless and secure, straight from your Vantack dashboard.

To get started with a merchant platform wallet of your own, sign up at 

Signing up on the platform will get you a merchant wallet and setup your initial default passkey.

<p class="slate-p " >Merchant wallets on our platform support two types of credentials:</p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">FIDO2 / Passkeys</strong>
FIDO2 credentials (commonly referred to as passkeys) offer a secure, passwordless authentication method based on public key cryptography. These credentials are typically linked to a user and stored in secure authenticators (e.g., platform authenticators like Face ID, or external security keys). Upon sign up, a default passkey will be added to your Vantack account. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Key Credentials (Raw Key Pairs)</strong>
This credential type allows you to register and use your own asymmetric key pairs (e.g., ECDSA or RSA). These keys are not tied to a user identity and can be stored and used programmatically—for example, in secure backend services or HSMs. </div></li></ol><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Remote Signing via API Credentials</h3><p class="slate-p " >If you&apos;re integrating with our platform programmatically (e.g., to initiate or approve wallet actions from a backend service), you can attach additional key credentials to your merchant wallet. This enables cryptographic signing of wallet operations <strong class="slate-bold">without requiring user login or passkey interaction</strong>.</p><p class="slate-p " >To do this:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Generate a key pair (ECDSA or RSA). </div></li><li class="slate-li " ><div style="position:relative">Register the public key via our API to create a new credential. </div></li><li class="slate-li " ><div style="position:relative">Use the corresponding private key in your remote service to sign requests. </div></li></ul><p class="slate-p " >This allows you to maintain secure, non-interactive access to wallet features while preserving the integrity of the signature flow.</p><div class="slate-div"><p class="slate-p " ><strong class="slate-bold">Note:</strong> You can associate multiple credentials with a merchant wallet, including both passkeys and key credentials, enabling flexibility for both user-interactive and backend-driven operations.</p></div><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Creating a Key Credential</h3><p class="slate-p " >In order to create a new Key Credential you can use the sample code provided in this GitHub Repository. The <a href="https://github.com/CoinSub/public/blob/d1aef044e62f1eeb9584ba8114b4c51a7c9aa39c/src/keyManager.ts#L7" target="_self">getOrCreateKeyPair</a> function will create a new keypair and store it locally, or read one from the file system if it&apos;s already created. Alternativelly, you can generate keys using tools like OpenSSL, or programmatically in your language of choice. Here&apos;s an example using OpenSSL to generate an ECDSA key pair:</p><div class="code-block-wrapper"  style="width:100%;min-width:100%" ><div class="code-block-header">Bash</div><pre class="slate-CodeBlockElement slate-code_block"><textarea id="publishedPageCodeblock" style="display:none !important; visibility: hidden; opacity: 0; width: 1px; height: 1px;" type="hidden"> </textarea><code class="language-bash keep-markup drop-tokens"><div class="slate-code_line"><div class="slate-code_line">Generate private key (P-256 curve)</div><div class="slate-code_line">openssl ecparam -name prime256v1 -genkey -noout -out private_key.pem</div><div class="slate-code_line"></div><div class="slate-code_line">Extract the public key</div><div class="slate-code_line">openssl ec -in private_key.pem -pubout -out public_key.pem</div></div></code></pre></div><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " >The rest of the flow will walk you through the platform APIs to create a new Key credential in our system. </p>

Merchant wallets on our platform support two types of credentials:

If you're integrating with our platform programmatically (e.g., to initiate or approve wallet actions from a backend service), you can attach additional key credentials to your merchant wallet. This enables cryptographic signing of wallet operations 

without requiring user login or passkey interaction

This allows you to maintain secure, non-interactive access to wallet features while preserving the integrity of the signature flow.

In order to create a new Key Credential you can use the sample code provided in this GitHub Repository. The 

 function will create a new keypair and store it locally, or read one from the file system if it's already created. Alternativelly, you can generate keys using tools like OpenSSL, or programmatically in your language of choice. Here's an example using OpenSSL to generate an ECDSA key pair:

The rest of the flow will walk you through the platform APIs to create a new Key credential in our system. 

<p class="slate-p " >Traditionally, sending crypto funds requires users to pay <em class="slate-italic">gas fees</em> using the native token of the blockchain they&apos;re operating on — for example, ETH on Ethereum or MATIC (POL) on Polygon. This can be a barrier, especially for users who don’t already hold these tokens.</p><p class="slate-p " >To improve the user experience, we’ve introduced <strong class="slate-bold">gasless transfers</strong> — a simple and seamless way to send funds without needing to hold or spend native tokens. This makes transactions faster, easier, and more accessible for all users.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >How Gasless Transfers Work</h3><p class="slate-p " >Gasless transfers on our platform can be executed in two different ways:</p><h4 class="slate-h4 " >1. Platform-Signed Transfers</h4><p class="slate-p " >In this mode, the <strong class="slate-bold">Platform handles the transaction signature on behalf of the Merchant</strong>.</p><p class="slate-p " >The Merchant grants the Platform permission to sign transfers up to a specified threshold (e.g. $100 per transfer). If a transfer exceeds this threshold, the Platform will request a manual signature from the Merchant before proceeding.</p><p class="slate-p " >This setup is ideal for minimizing operational friction while maintaining control over large or sensitive transfers.</p><h4 class="slate-h4 " >2. Merchant-Signed Transfers</h4><p class="slate-p " >Alternatively, the <strong class="slate-bold">Merchant can handle the signing process directly</strong>, maintaining full control over every transaction.</p><p class="slate-p " >In this case, each transfer must be individually approved and signed by the Merchant&apos;s system, typically via a connected private key or WebAuthn device.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Security Restrictions</h3><p class="slate-p " >To protect users from potential abuse or unauthorized activity, <strong class="slate-bold">gasless transfers are only permitted between wallets registered within our system</strong>. This ensures traceability, accountability, and reduces the risk of fraud or phishing attempts.</p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Traditionally, sending crypto funds requires users to pay 

 using the native token of the blockchain they're operating on — for example, ETH on Ethereum or MATIC (POL) on Polygon. This can be a barrier, especially for users who don’t already hold these tokens.

To improve the user experience, we’ve introduced 

 — a simple and seamless way to send funds without needing to hold or spend native tokens. This makes transactions faster, easier, and more accessible for all users.

Gasless transfers on our platform can be executed in two different ways:

Platform handles the transaction signature on behalf of the Merchant

The Merchant grants the Platform permission to sign transfers up to a specified threshold (e.g. $100 per transfer). If a transfer exceeds this threshold, the Platform will request a manual signature from the Merchant before proceeding.

This setup is ideal for minimizing operational friction while maintaining control over large or sensitive transfers.

Merchant can handle the signing process directly

, maintaining full control over every transaction.

In this case, each transfer must be individually approved and signed by the Merchant's system, typically via a connected private key or WebAuthn device.

To protect users from potential abuse or unauthorized activity, 

gasless transfers are only permitted between wallets registered within our system

. This ensures traceability, accountability, and reduces the risk of fraud or phishing attempts.

<p class="slate-p " >For merchants who prefer not to sign each transfer manually, we offer an option to <strong class="slate-bold">delegate signing responsibility to the Platform</strong> — securely and without compromising control or access to your wallet.</p><p class="slate-p " >With <strong class="slate-bold">Platform-Signed Transfers</strong>, you authorize us (just once) to generate and add a secure key pair to your merchant wallet. After this one-time setup, transfers can be executed without requiring your signature each time — making day-to-day operations smoother and faster.</p><p class="slate-p " >The setup involves just two steps:</p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Grant Permission</strong> – Authorize the Platform to generate and manage a key pair tied to your merchant wallet.</div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Send Transfers</strong> – Once set up, you can initiate transfers without needing to sign them yourself, as long as they fall within your pre-approved threshold.</div></li></ol><p class="slate-p " >It’s fast, secure, and optimized for scale. </p><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

For merchants who prefer not to sign each transfer manually, we offer an option to 

delegate signing responsibility to the Platform

 — securely and without compromising control or access to your wallet.

, you authorize us (just once) to generate and add a secure key pair to your merchant wallet. After this one-time setup, transfers can be executed without requiring your signature each time — making day-to-day operations smoother and faster.

It’s fast, secure, and optimized for scale. 

Platform-Signed Transfers

<p class="slate-p " >The first step is to authorize the Platform to sign gasless transfers on your behalf. This is done by requesting a <strong class="slate-bold">transfer permission challenge</strong> — a secure payload that confirms your intent to delegate limited signing rights to the Platform.</p><p class="slate-p " >The challenge you receive is structurally similar to a regular transfer challenge, but its purpose is to grant signing permission, not execute a transfer. It includes key information such as:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">The challenge identifier (used for signing — make sure to use the one inside the <code class="slate-code">challenge</code> object),</div></li><li class="slate-li " ><div style="position:relative">The supported credential type,</div></li><li class="slate-li " ><div style="position:relative">Additional metadata required for the signing process.</div></li></ul><p class="slate-p " >Once signed, the Platform securely generates and stores a dedicated key pair in an<strong class="slate-bold"> Secure Enclave</strong>. This key will be used to sign transfer requests on your behalf — but only for transactions under the predefined threshold.</p><div class="slate-div"><p class="slate-p " >⚠️ You remain in control: This permission is <strong class="slate-bold">revocable at any time</strong> by the merchant. You can disable Platform signing whenever needed.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Signing with an Existing Passkey</h3><p class="slate-p " >To approve the permission setup, the signature challenge must be signed using an <strong class="slate-bold">existing passkey</strong> already linked to the merchant&apos;s account/wallet. This ensures that only authorized entities can grant signing permissions.</p><p class="slate-p " >You can approve the challenge through:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Or directly via our<a href="https://test.coinsub.io/sign-test" target=""> test signing page</a></div></li><li class="slate-li " ><div style="position:relative">The <strong class="slate-bold">Platform UI</strong> under <strong class="slate-bold">Wallet → Security (comming soon)</strong></div></li></ul><p class="slate-p " ></p><p class="slate-p " >⚠️This step outputs a signature that is required for the second step (Grant Transfer Permission). </p></div><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

The first step is to authorize the Platform to sign gasless transfers on your behalf. This is done by requesting a 

 — a secure payload that confirms your intent to delegate limited signing rights to the Platform.

The challenge you receive is structurally similar to a regular transfer challenge, but its purpose is to grant signing permission, not execute a transfer. It includes key information such as:

Once signed, the Platform securely generates and stores a dedicated key pair in an

. This key will be used to sign transfer requests on your behalf — but only for transactions under the predefined threshold.

Request Transfer Permission

Content-Type

API-Key

Merchant-ID

Maximum amount that we can transfer on your behalf

max_allowance

data

status

A human-readable text providing additional information, intended to aid the client developer in understanding the error that occurred. This field is optional and should be avoided if there is a concern that it could leak sensitive information.

error

A code indicating the type of error that occurred. For client authentication failures, invalid_client is commonly used.

The 401 Unauthorized HTTP status code indicates that the request has not been executed because it lacks valid authentication credentials for the target resource. 

<p class="slate-p " >In this step, you complete the permission setup by submitting the signed challenge back to the Platform.</p><p class="slate-p " >Here&apos;s what you need to provide:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><code class="slate-code"><strong class="slate-bold">firstFactor</strong></code> – This contains the signed challenge.</div></li><li class="slate-li " ><div style="position:relative"><code class="slate-code"><strong class="slate-bold">challengeIdentifier</strong></code> – Include the specific identifier used during signing (from inside the <code class="slate-code">challenge</code> object).</div></li><li class="slate-li " ><div style="position:relative"><code class="slate-code"><strong class="slate-bold">credentialRequest</strong></code> – This is the full data object you received in response to the initial permission request.</div></li></ul><p class="slate-p " >Once submitted, the Platform will validate the request and, if successful, securely activate the signing key.</p><div class="slate-div"><p class="slate-p " >✅ That’s it — you&apos;re all set.
From this point on transfer requests under your configured threshold will no longer require a manual signature. </p></div><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><div class="slate-div"></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

In this step, you complete the permission setup by submitting the signed challenge back to the Platform.

Once submitted, the Platform will validate the request and, if successful, securely activate the signing key.

Grant Transfer Permission

challengeIdentifier

firstFactor

credentialRequest

<p class="slate-p " >You must provide the following parameters:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><code class="slate-code">to_address</code>: The recipient’s email address (must be registered with the Platform) or wallet - Use the same email used when creating a purchase session. </div></li><li class="slate-li " ><div style="position:relative"><code class="slate-code">amount</code>: Amount of tokens to transfer </div></li><li class="slate-li " ><div style="position:relative"><code class="slate-code">chainId</code>: ID of the target blockchain </div></li><li class="slate-li " ><div style="position:relative"><code class="slate-code">token</code>: Symbol of the token being transferred (e.g., USDC) </div></li></ul><p class="slate-p " >This endpoint transfers funds directly to the recepieng without requiring any signatures from the merchant. </p><div class="slate-div"><p class="slate-p " >⚠️ The recipient&apos;s email must be registered with the Platform to prevent unauthorized or accidental transfers.</p></div><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

You must provide the following parameters:

This endpoint transfers funds directly to the recepieng without requiring any signatures from the merchant. 

Create Transfer Request

to_address

amount

chainId

token

<p class="slate-p " >If you prefer full control over every transfer, you can opt to handle the signing process yourself. In this mode, <strong class="slate-bold">every transaction requires explicit approval from your side</strong>, using your existing passkey or credential.</p><p class="slate-p " >The process is simple and secure, and involves three steps:</p><ol class="slate-ol " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Request Transfer</strong> – Initiate a transfer by submitting the transaction details.</div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Sign Challenge</strong> – Sign the user action challenge using your existing passkey or private key.</div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Submit Challenge</strong> – Send the signed challenge back to start processing the transfer.</div></li></ol><p class="slate-p " >This approach ensures maximum control and security for every outgoing transaction. </p><p class="slate-p " ></p>

If you prefer full control over every transfer, you can opt to handle the signing process yourself. In this mode, 

every transaction requires explicit approval from your side

, using your existing passkey or credential.

The process is simple and secure, and involves three steps:

This approach ensures maximum control and security for every outgoing transaction. 

Merchant-Signed Transfers

<p class="slate-p " >This section outlines a set of API endpoints designed to retrieve information related to wallets, including wallet details, associated assets, and transaction history.</p><p class="slate-p " ></p><p class="slate-p " ></p>

This section outlines a set of API endpoints designed to retrieve information related to wallets, including wallet details, associated assets, and transaction history.

<p class="slate-p " >At <strong class="slate-bold">Vantack</strong>, a <strong class="slate-bold">product</strong> is a digital offer created by a merchant that users can purchase in exchange for access to a service, benefit, or digital experience. While many products are traditional subscriptions, they can also represent <strong class="slate-bold">one-time access</strong> or <strong class="slate-bold">single-purchase offerings</strong>.</p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h3 class="slate-h3 " >Core Aspects of a Vantack Product:</h3><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Merchant-Defined</strong>:
 Each product is owned and managed by a specific merchant, who determines its pricing, duration, and usage. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Descriptive Name</strong>:
 Every product has a clear and user-friendly title that communicates what the offering is. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Flexible Pricing Model</strong>:
 Products are priced in U.S. dollars, but payment may be made using crypto. The pricing supports both <strong class="slate-bold">recurring subscriptions</strong> and <strong class="slate-bold">one-time purchases</strong>. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Blockchain Integration</strong>:
 Payments are directed to a dedicated blockchain address, enabling secure, on-chain transactions. </div></li><li class="slate-li " ><div style="position:relative"><strong class="slate-bold">Lifecycle Status</strong>:
 Products can be marked as active (available for purchase), inactive (temporarily paused), or discontinued (retired), giving merchants control over their offerings. </div></li></ul><p class="slate-p " ></p><p class="slate-p " ></p>

 is a digital offer created by a merchant that users can purchase in exchange for access to a service, benefit, or digital experience. While many products are traditional subscriptions, they can also represent 

<p class="slate-p " >Payment agreements generate recurring payments through Vantack&apos;s payment network based on the pre-defined agreements signed by the customer. The customer is required to agree to any changes to a payment agreement. </p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

Payment agreements generate recurring payments through Vantack's payment network based on the pre-defined agreements signed by the customer. The customer is required to agree to any changes to a payment agreement. 

<p class="slate-p " >Payments in this system represent transactions that merchants receive from their customers. Each payment record contains important information about a transaction, such as:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">The amount paid</div></li><li class="slate-li " ><div style="position:relative">The currency used (like USDC)</div></li><li class="slate-li " ><div style="position:relative">When the payment was made</div></li><li class="slate-li " ><div style="position:relative">The status of the payment</div></li><li class="slate-li " ><div style="position:relative">Details about the customer</div></li><li class="slate-li " ><div style="position:relative">Information about what was purchased</div></li><li class="slate-li " ><div style="position:relative">Whether it was a one-time purchase or part of a subscription</div></li></ul><p class="slate-p " >Merchants can use this service to:</p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">View their complete payment history</div></li><li class="slate-li " ><div style="position:relative">Look up specific payment details</div></li><li class="slate-li " ><div style="position:relative">Monitor transaction statuses</div></li><li class="slate-li " ><div style="position:relative">Keep records of customer purchases</div></li></ul><p class="slate-p " >This helps merchants keep track of their business transactions and maintain a clear record of all payments they&apos;ve received through the platform.</p><p class="slate-p " ></p><p class="slate-p " ></p>

Payments in this system represent transactions that merchants receive from their customers. Each payment record contains important information about a transaction, such as:

This helps merchants keep track of their business transactions and maintain a clear record of all payments they've received through the platform.

<p class="slate-p " >A crypto payment system purchase session is a digital payment request, enabling users to specify and request a cryptocurrency amount from another party. 
Upon creation, the system generates a unique URL for the session, including details on the payment amount (if specified) and any additional instructions or metadata. This URL can be shared via email, messaging, QR code, or other methods, directing the payer to a secure payment interface to complete the transaction using their crypto wallet. This approach ensures precise payment amounts and offers a clear, trackable way to request and receive crypto payments, making it ideal for businesses, freelancers, and anyone needing a straightforward method for crypto transactions.
Purchase sessions securely transmit user information to Vantack upon initialization using a secure backchannel. Sessions can also be set to expire after a certain period, allowing for expirable quotes and adding a layer of security to the payment process.

</p><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

A crypto payment system purchase session is a digital payment request, enabling users to specify and request a cryptocurrency amount from another party. 
Upon creation, the system generates a unique URL for the session, including details on the payment amount (if specified) and any additional instructions or metadata. This URL can be shared via email, messaging, QR code, or other methods, directing the payer to a secure payment interface to complete the transaction using their crypto wallet. This approach ensures precise payment amounts and offers a clear, trackable way to request and receive crypto payments, making it ideal for businesses, freelancers, and anyone needing a straightforward method for crypto transactions.
Purchase sessions securely transmit user information to Vantack upon initialization using a secure backchannel. Sessions can also be set to expire after a certain period, allowing for expirable quotes and adding a layer of security to the payment process.



<p class="slate-p " ></p><p class="slate-p " >Purchase messages are designed for integrators who want to build and control their own checkout experience. Instead of redirecting customers to a hosted checkout page, integrators request a raw payload from Vantack, which contains all necessary transaction details.</p><p class="slate-p " >The integrator then signs this payload on the client or server side using their private key, following the <a href="https://eips.ethereum.org/EIPS/eip-712" target="_blank">EIP-712</a> structured data signing standard. Once signed, the integrator submits the message back to Vantack&apos;s API to finalize the transaction.</p><p class="slate-p " >This approach gives developers full flexibility over the user interface and transaction flow, while still leveraging Vantack&apos;s backend for transaction processing, validation, and reconciliation.</p><div class="slate-div"><p class="slate-p " >A short demo on how to sign a message using EIP-712 is available here: <a href="https://codesandbox.io/p/sandbox/eip712-forked-2scgy6" target="_blank">CodeSandbox EIP-712 Demo</a></p></div><p class="slate-p " ></p><p class="slate-p " ></p>

Purchase messages are designed for integrators who want to build and control their own checkout experience. Instead of redirecting customers to a hosted checkout page, integrators request a raw payload from Vantack, which contains all necessary transaction details.

The integrator then signs this payload on the client or server side using their private key, following the 

 structured data signing standard. Once signed, the integrator submits the message back to Vantack's API to finalize the transaction.

This approach gives developers full flexibility over the user interface and transaction flow, while still leveraging Vantack's backend for transaction processing, validation, and reconciliation.

<p class="slate-p " >Permit messages enable gasless token approvals by allowing users to sign an off-chain message that authorizes Vantack&apos;s smart contract to spend their tokens. Instead of requiring an on-chain approval transaction—which costs gas—users can simply sign a structured message with their wallet. This reduces friction at checkout and makes the payment process faster and more cost-effective.</p><p class="slate-p " >When you submit a signed purchase session, Vantack checks whether the user has already approved token spending. If so, the payment is processed immediately. If not, the response will include a permit message in typed data format. You can present this message to the user for signing. Once signed, submit it to Vantack to complete the approval and proceed with the transaction—all without requiring an additional on-chain approval step.</p><p class="slate-p " ></p><p class="slate-p " ></p>

Permit messages enable gasless token approvals by allowing users to sign an off-chain message that authorizes Vantack's smart contract to spend their tokens. Instead of requiring an on-chain approval transaction—which costs gas—users can simply sign a structured message with their wallet. This reduces friction at checkout and makes the payment process faster and more cost-effective.

When you submit a signed purchase session, Vantack checks whether the user has already approved token spending. If so, the payment is processed immediately. If not, the response will include a permit message in typed data format. You can present this message to the user for signing. Once signed, submit it to Vantack to complete the approval and proceed with the transaction—all without requiring an additional on-chain approval step.

Permit messages enable gasless token approvals by allowing users to sign an off-chain message that authorizes Vantack's smart contract to spend their

<p class="slate-p " ><span style="color:oklch(0.3039 0.04 213.68)">This comprehensive guide provides detailed information about integrating Vantack payment processing into your application. Vantack offers four distinct integration methods designed to accommodate different technical requirements and use cases, from simple no-code solutions to advanced API integrations with full customization capabilities.</span></p><p class="slate-p " ></p><div class="table-container" style="width:100%;
  min-width:100%;"><table class="slate-table" style="min-width:100%"><div class="published-table-header" style="width:100%;min-width:100%;"><div style="width:100px;">Option</div><div style="width:100px;">Integration Level</div><div style="width:100px;">Customization</div><div style="width:100px;">Hosted Checkout UI</div></div><colgroup ><col style="width:initial"><col style="width:initial"><col style="width:initial"><col style="width:initial"></colgroup><tbody class="slate-TableElement-tbody"><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >1. Standard Checkout Link</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">🔹 </span>No Code</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">✅ </span>(full control)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " ><span style="color:rgb(0, 0, 0)">✅</span></p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >2. Button Embed</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Low Code</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (button color)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅</p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >3. iFrame Embed</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Medium Code</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (full control)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅</p></td></div></tr><tr class="slate-tr " ><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >4. Headless API</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >🔸 Developer</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >✅ (fully programmable)</p></td></div><div class="slate-TableCellElement-content"><td class="slate-td"><p class="slate-p " >❌</p></td></div></tr></tbody></table></div><p class="slate-p " ></p><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><h2 class="slate-h2 " >Which Integration Option Should You Use?</h2><p class="slate-p " >Choosing the right integration depends on your <strong class="slate-bold">technical resources</strong>, <strong class="slate-bold">business model</strong>, and <strong class="slate-bold">how much control</strong> you want over the checkout experience.</p><h3 class="slate-h3 " ><span style="color:rgb(0, 0, 0)">🔹 </span>Standard Checkout Link – Best for Non-Technical Merchants</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Individual creators</div></li><li class="slate-li " ><div style="position:relative">Small merchants or service providers</div></li><li class="slate-li " ><div style="position:relative">Teams with no dev resources</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Zero development required</div></li><li class="slate-li " ><div style="position:relative">Shareable across any platform (email, social, website)</div></li><li class="slate-li " ><div style="position:relative">Fastest way to start accepting stablecoin payments</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Button Embed – Best for Low-Code Teams</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Marketing teams with light dev help</div></li><li class="slate-li " ><div style="position:relative">Shopify, WordPress, or Webflow users</div></li><li class="slate-li " ><div style="position:relative">Sites that need a call-to-action button with minimal backend setup</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Simple HTML embed</div></li><li class="slate-li " ><div style="position:relative">Button styling via <code class="slate-code">data-color</code></div></li><li class="slate-li " ><div style="position:relative">Redirects to secure hosted checkout</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Modal iFrame – Best for Custom Frontends That Want In-Site UX</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Sites with web developers</div></li><li class="slate-li " ><div style="position:relative">Businesses that care about seamless branding and user experience</div></li><li class="slate-li " ><div style="position:relative">Publishers, SaaS sites, or gated content platforms</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Fully embedded experience</div></li><li class="slate-li " ><div style="position:relative">Controlled modal styling</div></li><li class="slate-li " ><div style="position:relative">Checkout stays within your UI context</div></li></ul><div class="slate-hr"><hr contenteditable="false" class="slate-HrElement-hr"/></div><p class="slate-p " ></p><h3 class="slate-h3 " >🔸 Headless API – Best for Crypto-Native Platforms &amp; Advanced Teams</h3><p class="slate-p " ><strong class="slate-bold">Who it&apos;s for:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Web3 apps, dApps, DeFi platforms</div></li><li class="slate-li " ><div style="position:relative">Teams already managing wallets or signing flows</div></li><li class="slate-li " ><div style="position:relative">Platforms needing custom onboarding, wallet UX, or nonstandard product logic</div></li></ul><p class="slate-p " ><strong class="slate-bold">Why use it:</strong></p><ul class="slate-ul " ><li class="slate-li " ><div style="position:relative">Full control over the payment process</div></li><li class="slate-li " ><div style="position:relative">You manage wallet interaction and signing</div></li><li class="slate-li " ><div style="position:relative">Suitable for integrations with other on-chain or backend systems</div></li></ul><p class="slate-p " ></p><p class="slate-p " ></p><p class="slate-p " ></p>

This comprehensive guide provides detailed information about integrating Vantack payment processing into your application. Vantack offers four distinct integration methods designed to accommodate different technical requirements and use cases, from simple no-code solutions to advanced API integrations with full customization capabilities.

Option

Integration Level

Customization

Hosted Checkout UI

Choosing the right integration depends on your 

Standard Checkout Link – Best for Non-Technical Merchants

🔸 Button Embed – Best for Low-Code Teams

🔸 Modal iFrame – Best for Custom Frontends That Want In-Site UX

🔸 Headless API – Best for Crypto-Native Platforms & Advanced Teams

<p class="slate-p " >Webhooks allow real-time communication between systems.</p><p class="slate-p " >Webhooks are used to synchronize disparate systems by publishing automated messages with predefined payloads that can be interpreted by integrated systems. They allow real-time communication between applications, enabling instant updates and data sharing without the need for continuous polling.</p><p class="slate-p " >Our platform webhooks provide notifications when specific actions occur on your account, such as when a customer subscribes to a product, purchases a one-off product, makes a payment, or cancels a subscription. By setting up webhooks, you can automate processes and keep your systems in sync with our platform in real-time.</p><p class="slate-p " ></p><p class="slate-p " ></p>

Webhooks allow real-time communication between systems.

Webhooks are used to synchronize disparate systems by publishing automated messages with predefined payloads that can be interpreted by integrated systems. They allow real-time communication between applications, enabling instant updates and data sharing without the need for continuous polling.

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