ICPay

ICPay is a UK-based developer platform for accepting cryptocurrency payments across Solana, EVM networks, and the Internet Computer. Launched in September 2025, it provides a TypeScript SDK, embeddable Web Components, and a REST API that aim to reduce crypto payment integration to a few lines of code.

TypeScript SDK

The SDK ships as a single npm package (@ic-pay/icpay-sdk) and follows a two-key architecture: a publishable key for browser-side use and a secret key for server-side operations. Developers initialize the SDK with the appropriate key and optional wallet provider references, then create payment intents denominated in either USD amounts or native token values.

Chain and token selection uses shortcodes — base_usdc for USDC on Base, sol_usdc for USDC on Solana, ic_icp for ICP on the Internet Computer — so the same intent-creation pattern applies across all supported networks without writing chain-specific logic for each one. The package reached version 1.4.135 as of mid-2026, indicating steady iteration since launch.

Solana Integration

On Solana, ICPay connects to Phantom and Backpack wallets. Developers pass a solanaProvider to the SDK, which handles wallet detection, connection modals, balance queries, and transaction signing internally. Supported assets cover SOL and SPL tokens. The wallet connection logic is consistent across the frontend SDK and the embeddable widget layer, so teams adding payment functionality to existing applications do not need to build a separate wallet integration.

Multi-Chain Coverage

Alongside Solana, ICPay covers two additional ecosystems. On EVM chains, starting with Base, the SDK supports native assets and ERC-20 tokens via MetaMask, Coinbase Wallet, and WalletConnect. On the Internet Computer, it supports ICP and ICRC tokens with Plug, Internet Identity, Oisy, and NFID wallet connections. All three chains share the same API surface, so a developer building a multi-chain payment flow calls the same methods regardless of which network the user selects.

Embeddable Widgets

The icpay-widget library provides eight purpose-built Web Components with React wrappers, each targeting a different payment scenario: fixed or variable amount payment buttons, custom USD amount entry, tip jars with preset options, content paywalls, article previews with unlock mechanics, preset product catalogs for small commerce, fundraising thermometers tracking progress toward a goal, and transaction status displays.

The components are framework-agnostic and embed directly in HTML without a build step. Theming uses CSS variables or Tailwind CSS classes. Configuration accepts a publishable API key alongside per-chain recipient addresses — merchants specify a separate recipient address for each network they want to accept.

AI Agent Payment Protocols

ICPay targets AI agents as a first-class use case alongside human checkout flows. Two advanced protocols support machine-initiated transactions.

X402 implements the HTTP 402 "Payment Required" standard, letting a client settle access to an API resource by signing a payment transaction in-band rather than redirecting a user through a checkout page. ICPay's X402 v2 covers IC, EVM, and Solana, and accepts card or onramp-friendly settlement, making it applicable for agentic workloads where an AI client needs to pay for a service call autonomously.

ATXP (Advanced Transaction Payment Protocol) uses a quote/pay/execute pattern: the payer requests a quote, signs the payment, and the protocol links execution to the signed payment. This targets flows where confirming the exact token amount before signing matters — volatile-asset payments or multi-step agent pipelines where over-spending is a concern.

ICPay has also published an agent skill to the agentskills.so registry, which surfaces the SDK's payment capabilities as a callable tool for AI systems.

Relay Payments

The relay feature lets merchants accept funds and forward them directly to per-chain recipient addresses without custodying the assets. Incoming payments route to the configured destination on each network at settlement, reducing the steps between payer and final recipient.

Optional Fiat Onramp

An optional Transak integration converts fiat currency to crypto at the point of payment. Merchants who want to accept crypto from users without existing on-chain balances can enable the onramp without building a separate conversion path.

Payload CMS Plugin

ICPay ships a Payload CMS plugin (icpay-payload-plugin) for teams building content or commerce applications on that platform. The plugin brings payment intent creation and wallet connection functionality into Payload's admin and frontend surfaces.

Project Footprint

The GitHub organization at github.com/icpay maintains four public repositories: the core SDK, the widget library, the Next.js-based documentation site, and the Payload CMS plugin. The project identifies itself as UK-based and lists [email protected] as a contact address.