What is Capxul?
A Stripe-shaped SDK for financial operations — accounts, payments, payroll, and organizations — built for developers and agents.
Capxul is a financial-operations platform. The Capxul SDK gives your app accounts, payments, payroll, payment requests, and organizations through a TypeScript client and a set of React hooks — without your code ever touching the crypto substrate underneath.
import { CapxulProvider, useCapxulAccountBalance } from "@capxul/sdk-react";
function Balance() {
const balance = useCapxulAccountBalance();
if (balance.isLoading) return <span>Loading…</span>;
return <span>{balance.data?.balance.value} {balance.data?.balance.currency}</span>;
}The surface is Stripe-shaped
Money is just money. A developer using the SDK never has to know the words "Safe", "UserOp", "wei", or a chain id to move money. Crypto is the substrate, never the vocabulary — any custody term appearing in the consumer-facing surface is treated as a defect (a leak). You work with:
- Money — a currency, a decimal value, and a precision. Never wei.
- Accounts — a person's or org's pot of money, identified by an opaque id. Never an address.
- Payments — money sent to a validated recipient, a handle, an email, or a saved payee. Never a raw chain address.
Read the mental model and the money & accounts glossary for the full vocabulary.
Two products, one platform
- Capxul App is the customer-facing financial-operations product.
- Capxul SDK (these docs) is the platform layer it is built on — the same primitives are published for other product teams, external developers, and agents to build with.
Agent-native by design
The SDK is built with the expectation that agents participate in both building and operating products. Every capability is a safe, structured primitive an agent can compose: the MCP server exposes financial operations as tools, every docs page is available as raw markdown, and llms.txt indexes the whole site for machine readers.
Packages
| Package | What it is |
|---|---|
@capxul/sdk | The core TypeScript client — createCapxulClient and method bundles for auth, accounts, payments, orgs, payroll, and more. |
@capxul/sdk-react | React bindings — CapxulProvider plus ~60 hooks built on TanStack Query. |
@capxul/sdk-testing | Test utilities for SDK adapters and proof harnesses. |
@capxul/mcp | The Capxul MCP server — financial operations as agent tools. |
@capxul/sandbox | Sandbox CLI — create test publishable keys and send testnet faucet funds. |
All packages publish to npm on the 1.0.0-alpha.x train. Pin exact versions;
see Capability status for what is live today.
Where to start
- Building a product UI? Start with Getting started, then the hooks reference.
- Wondering what's real today? Read Capability status.
- Contributing to the platform? Start at Contributing.
- Building with agents? See the agent surface.