Meld API - Streamlined API Solutions for Fintech Integration

Meld API — The Complete Integration Guide for US Fintech Developers

If you're building a fintech product in the USA and need to connect users to crypto onramps, bank accounts, or stablecoin infrastructure — the Meld API is one of the most powerful tools available today. Rather than stitching together a dozen separate provider integrations, Meld gives developers a single, unified API layer to manage everything from fiat-to-crypto purchases to bank account linking and virtual payouts.

This guide covers everything a US developer or fintech team needs to understand about the Meld API: what it does, how it works, its core products, real code examples, integration steps, and answers to the most common questions.

What Is the Meld API?

The Meld API is a global digital asset and stablecoin network that bridges financial institutions and applications, enabling seamless onramp and offramp services across the Meld Network. Meld For US-based fintech companies, it solves one of the hardest engineering problems: connecting users to crypto and banking infrastructure without building and maintaining separate integrations for each provider.

With just a few lines of code, developers using the Meld API can boost conversion rates by 55% and unlock customers across 200+ countries, 113 fiat currencies, 500+ crypto tokens, and 50+ payment methods. Meld

Website: https://www.meldapi.com

Core Products in the Meld API Suite

The Meld API is not a single endpoint — it's a platform with three specialized product tracks plus a bank linking layer:

How the Meld API Works: Architecture Overview

At its core, the Meld API acts as an orchestration layer between your application and a network of licensed financial service providers. Here's how a typical crypto purchase flows through it:

User App (US)
    │
    ▼
Meld API (Single Integration Point)
    │
    ├──► Onramp Provider Selection (RampScore™ Algorithm)
    │         └── Topper / Transak / Robinhood Connect / Stripe / Coinbase / etc.
    │
    ├──► KYC / Bank Linking (OAuth2)
    │
    ├──► Payment Processing (ACH / Credit Card / Bank Transfer)
    │
    └──► Crypto Settlement → User Wallet

Meld API: Get a Quote (Code Example)

The first step in any Meld White-Label integration is fetching real-time quotes from available onramp providers. Here's what a quote request and response looks like:

Request:

POST /v1/quotes
{
  "countryCode": "US",
  "sourceCurrencyCode": "USD",
  "destinationCurrencyCode": "BTC",
  "paymentMethodType": "CREDIT_DEBIT_CARD",
  "sourceAmount": 100
}

Response (single quote example):

{
  "quotes": [
    {
      "transactionType": "CRYPTO_PURCHASE",
      "sourceAmount": 100.00,
      "sourceCurrencyCode": "USD",
      "totalFee": 4.18,
      "networkFee": 0.28,
      "transactionFee": 2.9,
      "partnerFee": 1.0,
      "destinationAmount": 0.00105423,
      "destinationCurrencyCode": "BTC",
      "exchangeRate": 94856.0,
      "paymentMethodType": "CREDIT_DEBIT_CARD",
      "serviceProvider": "TOPPER",
      "rampIntelligence": {
        "rampScore": 21.66,
        "lowKyc": false
      }
    }
  ]
}

The rampScore field is powered by Meld's RampScore™ algorithm — Meld scores each onramp based on price, breadth of payment methods, and conversion on the Meld network, and updates this score based on millions of monthly transactions so users consistently get the best price and settlement experience.

Create a Transaction (Code Example)

Once the user selects a quote, you initiate the transaction:

POST /v1/transactions
{
  "countryCode": "US",
  "sourceCurrencyCode": "USD",
  "destinationCurrencyCode": "BTC",
  "paymentMethodType": "CREDIT_DEBIT_CARD",
  "sourceAmount": 100,
  "serviceProvider": "TRANSAK",
  "walletAddress": "bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh"
}

Meld handles the rest — payment routing, KYC checks, and crypto delivery to the wallet — and sends real-time status updates to your webhook endpoint.

Webhook Events: Real-Time Transaction Tracking

Meld uses webhooks to push transaction status updates to your backend. A typical webhook payload looks like this:

{
  "eventType": "TRANSACTION_CRYPTO_PENDING",
  "eventId": "AAsuLXHXD3mS1cjNBuHHzv",
  "timestamp": "2025-03-01T16:36:41.717262Z",
  "accountId": "WQ5RyhdFzE45qjsomdzQ1u",
  "version": "2025-03-01",
  "payload": {
    "paymentTransactionId": "WePZCYJW7cdXR7SxUMp8mE",
    "externalCustomerId": "user_12345",
    "paymentTransactionStatus": "PENDING",
    "transactionType": "CRYPTO_PURCHASE",
    "sessionId": "WePjVaT4iBHPpqW49F419x"
  }
}

Key webhook statuses to handle in your app:

Meld Bank Linking API

Beyond crypto, the Meld API includes a full bank linking product for US fintech apps that need to connect to users' financial accounts. This is comparable to Plaid but offered as part of the same unified Meld platform.

Bank Linking Products Available:

Bank linking uses a secure OAuth2-based widget flow — Meld's bank linking and KYC orchestration enables unified authentication across the Meld Network, and they never store individual identity documents or payment method information, with all stored data governed by independently audited security policies. 

Supported Onramp Partners (US Market)

Meld's integration enables support for multiple providers including Meso, Coinbase, Robinhood Connect, Stripe, Unlimit, Topper, Transak, and Blockchain.com — all through a single API.

Meld API Integration Steps (For US Developers)

Getting started with the Meld API follows a clear four-step process:

Step 1: Accept Dashboard Invite Create your Meld account and access the developer dashboard at meld.io.

Step 2: Add Service Providers Configure which onramp providers you want to activate (Transak, Topper, Coinbase, etc.) and set up their credentials within the Meld dashboard.

Step 3: Make Your First API Call Use your API key to authenticate and fetch quotes in the sandbox environment. Meld automatically enables several test onramps for sandbox testing.

Step 4: Set Up Webhooks Configure a webhook endpoint in your backend to receive real-time transaction events. Meld supports webhook retries and authentication signatures for security.

Step 5: Go Live Switch from sandbox to production credentials, complete compliance review, and launch.

Security & Compliance

For US fintech companies, compliance is non-negotiable. The Meld API is built with this in mind:

• KYC Orchestration — Meld handles identity verification across providers, reducing your compliance burden

• No PII Storage — Identity documents and payment method data are never permanently stored by Meld

• Independent Security Audits — Data security policies are independently reviewed and audited

• OAuth2 Authentication — All bank linking uses industry-standard OAuth2 protocols

• Webhook Signature Verification — Prevent spoofed events with HMAC signature validation

• Sandbox Environment — Fully isolated testing environment before any real money moves

Why US Fintechs Choose the Meld API

Integrating with multiple onramp and offramp providers is challenging to manage in-house, requiring a dedicated team to oversee and implement — which means fewer engineering resources working on your core product. Meld The Meld API solves this by collapsing that entire maintenance burden into a single integration point.

Key reasons US fintech teams use Meld:

• Single API, multiple providers — No more managing 5–10 separate onramp contracts and integrations

• RampScore™ routing — Automatically routes transactions to the highest-converting provider in real time

• Faster time to market — Meld helped Phantom reduce go-to-market costs and speed up time to launch by minimizing development and testing efforts Meld

• Broad payment method support — ACH, credit/debit cards, Google Pay, and more

• Built for scale — Handles millions of monthly transactions across the network

FAQ

Q1: What is the Meld API used for? 

The Meld API is used by US fintech developers to integrate crypto onramp/offramp capabilities, bank account linking, and stablecoin payment infrastructure into their applications — all through a single unified API.

Q2: How is the Meld API different from Plaid? 

Plaid is focused primarily on bank account linking and financial data access. The Meld API covers crypto onramp/offramp, stablecoin infrastructure, virtual accounts, and bank linking together under one platform. For teams building crypto-adjacent or digital asset products, Meld offers capabilities Plaid doesn't provide.

Q3: Does the Meld API support US users specifically?

Yes. The Meld API fully supports US-based users including USD as a source currency, US payment methods (ACH, credit/debit cards), and compliance with US KYC/AML requirements through its onramp partner network.

Q4: What is RampScore™ in the Meld API? 

RampScore™ is Meld's proprietary routing algorithm that scores each connected onramp provider based on price, payment method coverage, and transaction conversion rates. When a user initiates a purchase, Meld automatically routes them to the highest-scoring provider for their specific transaction profile.

Q5: Is there a sandbox environment for testing the Meld API? 

Yes. Meld provides a fully functional sandbox environment where developers can test end-to-end flows including quotes, transactions, webhooks, and bank linking — without using real money or real user credentials.

Q6: What payment methods does the Meld API support in the USA? 

For US users, Meld supports credit and debit cards, ACH bank transfers, and in some cases Google Pay — depending on the onramp provider selected. Payment method availability varies by provider and is surfaced in the quote response.

Q7: How does the Meld API handle KYC for US users? 

Meld's onramp providers handle KYC directly for crypto transactions. For bank linking, Meld uses OAuth2 flows that authenticate users with their bank — no credentials are stored by Meld. Identity documents are never permanently stored on Meld's platform.

Q8: How long does it take to integrate the Meld API? 

A basic integration using the Meld Checkout (hosted widget) can be done in hours. A full white-label API integration with custom UI and webhook handling typically takes 1–2 weeks for an experienced development team.

Q9: How does FintegrationFS help with Meld API integration? 

FintegrationFS is a US-focused fintech development company that has built production applications using the Meld API. We handle end-to-end implementation — from API setup and onramp configuration to webhook handling, compliance alignment, and deployment — so your team can stay focused on product.