Blockchain API for Finance: What It Does
What a blockchain API does for payment and finance teams: wallets, transfers and deposit webhooks, plus what it does not cover, such as KYC and reporting.
Reviewed by Maurice Sobiera
A blockchain API for finance is a REST interface that lets a company’s backend create wallets, send transactions and receive deposit notifications on public blockchains without running its own nodes. Chaingateway offers this for Bitcoin, Ethereum, BNB Smart Chain, Tron, Solana, Polygon and Arbitrum. It moves value on chain. It does not replace compliance processes.
Which finance problem can a blockchain API address?
A blockchain API addresses the technical side of moving value on chain: wallets, transfers and confirmation of incoming payments. Cross-border payments are a typical motivation. The Financial Stability Board (FSB) describes the targets that the G20 set for them in its roadmap report.
| Segment | Cost target | Speed target (by end-2027) |
|---|---|---|
| Retail payments | Average cost of no more than 1 percent, no corridor above 3 percent, by end-2027 | 75 percent of payments available to the recipient within one hour |
| Remittances | Average cost of sending $200 of no more than 3 percent by 2030, no corridor above 5 percent | 75 percent of payments available within one hour |
| Wholesale | No target set | 75 percent credited within one hour |
An on-chain transfer is a technical way to approach the speed targets, because a confirmed transaction settles between the two wallets without intermediary banks. The cost targets depend on more than the transfer. Network fees, the conversion from and to local currency and the licensing of the parties involved all count. An API removes none of these. Treat any claim about cost savings as something to measure in your own flow.
What does the API do?
The Chaingateway API covers the steps of an on-chain payment flow through HTTP endpoints. You authenticate with a bearer token, and a request header selects mainnet or testnet.
- Create and manage addresses, for example
POST /api/v2/ethereum/addresses, and read balances. - Send native coins and tokens, for example
POST /api/v2/tron/transactions/trc20or the ERC-20 endpoints. - Read transactions and receipts.
- Register webhooks that notify your endpoint when a monitored address receives a transaction.
Webhooks are available on Bitcoin, Ethereum, BNB Smart Chain, Tron, Polygon and Arbitrum. Solana has no webhooks, so you detect deposits there by querying transactions. Webhook notifications are not retried automatically. Failed notifications are listed, and you can ask for them to be sent again, so your system should reconcile against the API as well. The article on webhook delivery guarantees explains how to design for this.
Chaingateway is non-custodial, so the service does not hold your funds.
What does a payment flow look like end to end?
A deposit flow has five steps, and each maps to an API call.
- Create an address for the customer or the order with
POST /api/v2/{chain}/addresses. On Bitcoin the resource is calledwallets. - Register a webhook for that address with
POST /api/v2/{chain}/webhooks, before the customer pays. - Receive the notification at your endpoint and verify its
X-Signatureheader. - Confirm the transaction with the API and credit the order after enough confirmations.
- Move the funds to your own treasury wallet with a transfer endpoint, for example
POST /api/v2/ethereum/transactions/erc20.
The table shows where this flow is available. The path segment {chain} is one of bitcoin, ethereum, bsc, tron, polygon, arbitrum or solana.
| Network | Addresses and transfers | Webhooks |
|---|---|---|
| Bitcoin | Yes | Yes |
| Ethereum | Yes | Yes |
| BNB Smart Chain | Yes | Yes |
| Tron | Yes | Yes |
| Polygon | Yes | Yes |
| Arbitrum | Yes | Yes |
| Solana | Yes | No |
Does a blockchain API handle compliance?
No. An API does not perform KYC, sanctions screening or regulatory reporting. Those duties stay with the company that offers the service, and which of them apply depends on its business model and jurisdiction. Our article on crypto payment KYC describes the checks to settle before you integrate.
What the chain does provide is a record. The US National Institute of Standards and Technology (NIST) explains in NISTIR 8202 that Bitcoin users are pseudonymous: the person behind an account is not named, but account identifiers are visible and all transactions are public. Your records can reference transaction hashes that anyone can verify. Linking an address to a customer is something your own onboarding process must do.
NIST also states that blockchains are tamper evident and tamper resistant, but not completely immutable. The newest blocks can be replaced by a longer competing chain. This is why most users wait for several block confirmations before they treat a payment as final. Decide the number of confirmations that your risk policy requires, and credit customers only after that point.
How do I start?
Start on a testnet. Add the X-Network: testnet header to your requests to use the test networks, create an address, send a small transfer and register a webhook to see a notification arrive. Chaingateway has a 7-day free trial that needs no card and no identity verification to begin. Paid plans start at €49 per month, or €490 per year.
For a practical build plan, read how to create a crypto wallet with an API and how crypto payment webhooks work.
Ready to build this yourself? Get your API key — 7-day trial, no card required — or see the Blockchain API for the full endpoint reference.