Bridge

API architecture: customers, transfers, and auto-routing primitives

Bridge's API reduces stablecoin movement to a small set of composable objects so a fintech never touches chains or wallets directly.

• Customer carries KYC/AML state; nothing settles until the customer is approved.
• Transfer is a one-off source → destination movement across crypto + fiat rails.
• Virtual Account = fiat bank details that auto-convert incoming fiat to stablecoin; Liquidation Address = on-chain address that auto-converts incoming crypto to a fiat/crypto destination.
• External Account holds payout bank details; Bridge Wallets custody balances; Developer Fees monetize volume.
• Webhooks deliver state changes — the integrator treats them, not the HTTP response, as the source of truth.

Issuance economics: reserves, T-bill yield, and the developer share

The strategic shift is who keeps the float. Legacy issuers (Circle, Tether) pocket the yield on reserves; Bridge inverts this to win developers.

• USDB / Open Issuance tokens are 1:1-backed by cash, money-market funds, and short-term US Treasuries.
• Reserves earn the short-term rate (~3–4%); Bridge shares the MAJORITY of that yield back as a developer fee.
• This makes the stablecoin a revenue line for the integrator — a structural lever Circle/Tether don't offer at the API layer.
• Rate risk: the model's economics compress directly with Fed rate cuts.
• Reserve managers/custodians: BlackRock (USDB), plus Fidelity and Superstate for Open Issuance.

Stripe distribution: from API to default rail

The ~$1.1B acquisition (closed Feb 4, 2025, Stripe's largest) is fundamentally a distribution play — Bridge gets Stripe's merchant base; Stripe gets a stablecoin backbone.

• Stripe's stablecoin Financial Accounts (launched May 20, 2025, 100+ countries) hold USDC and Bridge's USDB.
• Bridge + Visa stablecoin-linked cards launched in LatAm (Apr 2025) and target 100+ countries by end of 2026.
• Stablecoins moved ~$15.6T in 2024 (on par with Visa); B2B stablecoin payments hit ~$226B in 2025 — the TAM behind the bet.
• Concentration risk cuts both ways: Bridge's roadmap is now Stripe's roadmap.

Compliance & regulatory posture

As a bank-adjacent issuer, Bridge's moat increasingly is its regulatory standing under the new US stablecoin regime.

• Banking partner Lead Bank backs the card / fiat rails; KYC/AML and sanctions screening are built into the Customer object.
• Received OCC conditional approval to organize a federally-chartered national trust bank (Feb 2026) — would let it issue stablecoins and custody reserves under direct OCC oversight. [verify final approval]
• USDB ships with on-chain + off-chain validations, whitelisting, and freeze/burn controls for sanctions compliance.
• Operates under the emerging GENIUS Act framework for US payment stablecoins. [verify current status]

Architecture

Bridge sits between the chains and the banking system as a single orchestration API. The core objects are Customers (which carry KYC state), Transfers (a source → destination money movement), and the deposit primitives that make money move automatically: Virtual Accounts (fiat bank details that convert incoming fiat to stablecoin) and Liquidation Addresses (on-chain addresses that auto-convert and route incoming crypto to a fiat or crypto destination). External Accounts hold a customer's payout bank details; Bridge Wallets custody balances; Developer Fees let the integrator skim a fee on each transfer; and Cards provision Visa cards that draw down a stablecoin balance. State changes are delivered via Webhooks. All calls authenticate with a server-side Api-Key header and use an Idempotency-Key to make POSTs safe to retry.

Integration shape

Server-to-server REST. Onboard a Customer and clear KYC (hosted KYC Links or direct submission), attach an External Account for fiat payout, then either create one-off Transfers or stand up a Virtual Account / Liquidation Address so funds convert and route automatically. Configure Developer Fees once to monetize volume, and subscribe a Webhook endpoint to track Customer/KYC, transfer, and card events. Cursor-based pagination on all list endpoints.

API surface

POST /customers + POST /kyc-links

Create a customer and generate a hosted KYC link; KYC/AML and sanctions screening clear before money can move.

POST /transfers

Move money source → destination across crypto + fiat rails (e.g. fiat in → USDC out); specify amount, currency, and on/off-ramp details.

POST /virtual-accounts

Issue per-customer fiat bank details (ACH/SEPA/wire); incoming fiat auto-converts to a stablecoin and lands at the destination.

POST /liquidation-addresses

Create an on-chain address that auto-converts incoming crypto and routes it to a fiat external account or another address.

POST /external-accounts

Register a customer's destination bank account for fiat payouts; reusable across transfers.

PUT /developers/fees

Configure the developer fee taken on transfers; paired with POST /developers/fee-external-account for payout.

POST /card-accounts + POST /webhooks

Provision a Visa card that spends from a stablecoin balance; subscribe webhooks for transfer, KYC, and card events.

Minimal integration

Create a liquidation address that auto-converts incoming USDC to USD and pays out to a bank account.

const BRIDGE_API = 'https://api.bridge.xyz/v0';

async function createLiquidationAddress(customerId: string, externalAccountId: string) {
  const res = await fetch(`${BRIDGE_API}/customers/${customerId}/liquidation_addresses`, {
    method: 'POST',
    headers: {
      'Api-Key': process.env.BRIDGE_API_KEY!,        // server-side only
      'Idempotency-Key': crypto.randomUUID(),         // safe to retry
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      chain: 'ethereum',
      currency: 'usdc',
      // incoming USDC is converted and paid out as USD via ACH
      destination_payment_rail: 'ach',
      destination_currency: 'usd',
      external_account_id: externalAccountId,
    }),
  });

  if (!res.ok) throw new Error(`Bridge error ${res.status}: ${await res.text()}`);
  return res.json(); // -> { id, address, chain, currency, ... }
}

Build notes

• Treat webhooks (not the API response) as the source of truth for transfer + KYC state; verify the signature and make handlers idempotent.
• A Customer must reach an approved KYC state before transfers settle — gate money movement on the KYC webhook.
• Liquidation addresses and virtual accounts are the 'set-and-forget' primitives: stand one up per customer and money routes automatically without per-payment API calls.
• [verify exact base URL/version, path casing (snake_case vs hyphen), and supported chains/rails against the live apidocs.bridge.xyz — these evolve].