Crypto infrastructure without custody.
The API for businesses that need to know when money moves on chain, without giving us the keys.
You supply an xpub or a plain address. Bitcoin runs on our nodes; EVM reads through yours. We watch those addresses, detect transfers, track them through their confirmation policy, and push signed events to your endpoint. Your keys, your signing and your ledger never leave your side of the line.
Take deposits
The core job: an address per user, order or account, and an event you can credit from.
Casinos and sportsbooks
One deposit address per player on Bitcoin or Base, watched from creation. Detected transfers arrive as signed events your backend already knows how to handle, so wagering and risk stay entirely on your side.
POST /v1/addresses · POST /v1/webhook-endpoints
Fintech apps
Add on-ramp deposits without building ingestion, cursors, reorg handling or delivery. You receive exact amounts and block evidence, and you decide what a confirmed deposit unlocks.
POST /v1/wallets/{id}/addresses
Marketplaces
Derive a unique address per order from your public xpub. The address round-trips with your own reference, so reconciliation is a lookup in your database, not a matching exercise in ours.
GET /v1/addresses · GET /v1/transfers
Merchant payments
Accept BTC and stablecoin payments without becoming a payment processor or a custodian. We watch and report, you credit, and every event can be re-checked against the chain.
GET /v1/transfers/{id}
Fund accounts
Stablecoin funding where the balance lives in your ledger, not in ours.
Exchanges
Deposit addresses per customer on Bitcoin and Base, a per network confirmation policy, and revisions that survive reorgs. Sweeps and withdrawals need the preparation and broadcast API, which is in progress.
PUT /v1/confirmation-policies/{networkId}
Trading platforms
Credit trading balances from confirmed stablecoin deposits while custody stays with your signer. Policy versions are pinned per transfer, so a later policy change cannot silently reinterpret an old deposit.
GET /v1/transfers?status=confirmed
OTC desks and brokers
Watch settlement addresses on both sides of a trade and confirm incoming funds with evidence you can hand to a counterparty: transaction hash, block hash and receipt log position.
GET /v1/transactions/{chainId}/{hash}
Watch and normalize
For teams whose product is the wallet, the market or the game.
Wallet apps
Normalized chain events with stable identity: a logical transfer, its inclusion history and its lifecycle revisions, rather than raw logs or UTXO diffs you have to interpret per chain. Bitcoin deposits carry txid:vout; EVM carries the receipt log position.
GET /v1/transfers · usage:read
Prediction markets and gaming
Chain events in, internal accounting stays yours. Monitoring keeps running through pause and resume, and any gap in coverage is reported as a gap instead of being papered over.
POST /v1/addresses/{id}/pause
Pay out
Leaving a customer account needs the outgoing half of the product. It is the next work item, not a shipped feature.
Payroll and payouts
RoadmapPrepare unsigned transfers, validate them locally, sign in your own environment and ask us to broadcast the signed bytes. Same-hash retries are not billed twice, and a timeout is treated as uncertain, never as failure.
POST /v1/transactions/prepare · POST /v1/transactions/{id}/broadcast
Exchange withdrawals
RoadmapThe same flow for customer withdrawals: we never hold a key, and nonce ownership stays explicitly with you rather than being promised by a lock.
planned
What stays yours
Keys and signing. We never ask for a seed, a private key or an xprv, and the API rejects them at the boundary. Every address we issue can be reproduced locally from the public material you gave us.
Balances, sweeps and gas. A transfer record means we observed a transfer on chain. It never credits an account, never moves a coin, and never becomes a second ledger.
Risk and crediting. Confirmed means a policy was met on recorded evidence. Whether that unlocks a bet, a trade or a withdrawal is your decision, made with your own rules.
Where we are today
Bitcoin mainnet and signet run on Retransact nodes and followers: BIP84 derivation, outputs-only detection and exact satoshis. Base Sepolia runs the EVM pilot, Base mainnet is staged behind it, and Ethereum follows through the same adapter. Supported transfers are native value, an allowlisted ERC-20 set led by USDC, and Bitcoin outputs.
On EVM you bring the RPC; Bitcoin needs no endpoint. Not shipped yet, and stated plainly rather than implied: managed EVM nodes, Solana and Tron, automated sweeps, and the outgoing prepare and broadcast API. Teams that need those today should not sign up expecting them tomorrow.
Bring the addresses you already control — a plain address or a BIP84 xpub on Bitcoin, or an EVM endpoint — and see the first signed event land in your own endpoint. Test environments include $5 of usage each month.