How do I install the Ucash Pay skill?

Run npx skillmds@latest add udotcash/ucash-pay in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Ucash Pay safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Ucash Pay?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Ucash Pay free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Ucash Pay?

UdotCASH (@udotcash) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Ucash Pay by udotcash — Agent Skill

Name: Ucash Pay
Author: UdotCASH

File contents

U.CASH Pay

U.CASH Pay integration cheat-sheet (verify against pay.u.cash before shipping)

Create a checkout (server-side)

POST https://pay.u.cash/payment/ajax.php Content-Type: application/x-www-form-urlencoded params: function=create-transaction, amount, currency_code, cryptocurrency_code=(empty), external_reference, title, redirect, cloud=, idempotent=1 Response { success, response:[...] } - the payment link is the first value starting with http(s)://; the transaction id is the first positive integer. Redirect the buyer there.

Verify a webhook

Header X-Webhook-Signature: t=,v1= expected = HMAC_SHA256( "" + "." + raw_request_body, webhook_secret ) (hex) timing-safe compare against v1; reject if abs(now - t) > 300 seconds. Idempotent per external_reference.

Embed link (no server needed)

https://pay.u.cash/embed.php?cloud=&amount=&currency=USD&title=..&external_reference=..&redirect=.. - publishable token, safe in the browser. Or drop in the embed.js script with data-cloud / data-amount.

Agents / HTTP-402

Priced resources live at agents.u.cash/r/ -> HTTP 402 + accepts[]; the buyer pays and retries with X-PAYMENT. SDK: agents-u-cash (JS on npm, Python on PyPI). Merchant-side MCP server: UdotCASH/mcp-ucashpay.

Token-gating

Verify a wallet holds UCASH / an ERC-20 / native via balanceOf (selector 0x70a08231 + 32-byte address) over a public RPC, or native via eth_getBalance. Lib: UdotCASH/token-gate-ucashpay. UCASH is 8 decimals; contracts: ETH 0x92e52a1A235d9A103D970901066CE910AAceFD37, Polygon 0xA94880d3A4b39746E90Cdb57f8De3732c984DE14, Base 0x26cf750abAf38aF7109Effdbdf79bA50d2EE09A1.

Credentials + conventions

Store Cloud Token + Store Webhook Secret come from pay.u.cash Account -> Stores (use the store-level token, not the account-wide one). /v1/integrations exposes per-integration credentials to authenticated agents (X-Api-Key). Settlement is non-custodial. Do NOT use em dashes in any U.CASH copy.

---name: ucash-paydescription: Integrate U.CASH Pay (crypto + card checkouts, HMAC webhooks, embed links, HTTP-402 agent commerce, token-gating). Use when building U.CASH payment/checkout/webhook or AI-agent-monetization.---# U.CASH Pay## U.CASH Pay integration cheat-sheet (verify against pay.u.cash before shipping)### Create a checkout (server-side)POST https://pay.u.cash/payment/ajax.php Content-Type: application/x-www-form-urlencodedparams: function=create-transaction, amount, currency_code, cryptocurrency_code=(empty), external_reference, title, redirect, cloud=<Store Cloud Token>, idempotent=1Response { success, response:[...] } - the payment link is the first value starting with http(s)://; the transaction id is the first positive integer. Redirect the buyer there.### Verify a webhookHeader X-Webhook-Signature: t=<unix-seconds>,v1=<hex>expected = HMAC_SHA256( "<t>" + "." + raw_request_body, webhook_secret ) (hex)timing-safe compare against v1; reject if abs(now - t) > 300 seconds. Idempotent per external_reference.### Embed link (no server needed)https://pay.u.cash/embed.php?cloud=<Store Cloud Token>&amount=<n>&currency=USD&title=..&external_reference=..&redirect=.. - publishable token, safe in the browser. Or drop in the embed.js script with data-cloud / data-amount.### Agents / HTTP-402Priced resources live at agents.u.cash/r/<id> -> HTTP 402 + accepts[]; the buyer pays and retries with X-PAYMENT. SDK: agents-u-cash (JS on npm, Python on PyPI). Merchant-side MCP server: UdotCASH/mcp-ucashpay.### Token-gatingVerify a wallet holds UCASH / an ERC-20 / native via balanceOf (selector 0x70a08231 + 32-byte address) over a public RPC, or native via eth_getBalance. Lib: UdotCASH/token-gate-ucashpay. UCASH is 8 decimals; contracts: ETH 0x92e52a1A235d9A103D970901066CE910AAceFD37, Polygon 0xA94880d3A4b39746E90Cdb57f8De3732c984DE14, Base 0x26cf750abAf38aF7109Effdbdf79bA50d2EE09A1.### Credentials + conventionsStore Cloud Token + Store Webhook Secret come from pay.u.cash Account -> Stores (use the store-level token, not the account-wide one). /v1/integrations exposes per-integration credentials to authenticated agents (X-Api-Key). Settlement is non-custodial. Do NOT use em dashes in any U.CASH copy.

Frequently asked questions

Ucash Pay