Developers

One API for the regulated middle.

Issue wallets, move money, and react to events through a typed, idempotent API. Identical requests are safe to retry; conflicting ones are caught before they cause damage.

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Typed errorsIdempotentOpenAPI 3.0Signed webhooks

withdrawals.create.ts

import { Cystody } from "@cystody/sdk";const cystody = new Cystody({ apiKey: process.env.CYSTODY_KEY });// Idempotent, safe to retry, never double-spends.const withdrawal = await cystody.withdrawals.create(  {    accountId: "acct_8f21",    asset: "USDC",    network: "base",    to: "0x9f...",    amount: "2500.00",  },  { idempotencyKey: "payout-2026-06-17" },);withdrawal.status; // "pending", durable from here

Surfaces

Three APIs, one model.

Each surface is scoped to its audience, with the same conventions: typed errors, idempotency, and an OpenAPI reference.

Public APIFor your application. API-key auth, rate-limited.

Portal APIPowers the merchant dashboard. Session + MFA.

Admin APIPlatform operations. Session, MFA, and granular roles.

Conventions

Built to be retried.

Idempotent: Retry safely; conflicts return 409
Typed errors: Specific codes; failing field named
Reference: OpenAPI 3.0, generated from source
Webhooks: Signed, retried, dead-lettered

SDKs

In the languages you ship.

With built-in retries, idempotency-key generation, and webhook signature verification.

Go · roadmapNode / TypeScript · roadmapPython · roadmap

Read the docs. Ship in a sprint.

The hard parts are already built. Your integration is mostly wiring, and we'll help with that.

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