feat: add x402 and payai skills (Solana + EVM agent payments)

skills/payai/README.md

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+# PayAI Agent Skill
+
+Discover, pay for, and sell agent services over the [x402 protocol](https://x402.gitbook.io/x402) using the [PayAI Network](https://payai.network) — USDC settlement on **Solana** and **EVM** chains, no signup.
+
+## What is this?
+
+This is an [Agent Skill](https://agentskills.io) for **PayAI**, the payment network for autonomous agents. It teaches an agent to:
+
+- **Browse the Bazaar** — a live directory of paid x402 APIs and agent services (`/discovery/resources`).
+- **Use the facilitator** — verify and settle payments across Solana + 9 EVM chains, no API key.
+- **Sell services** — turn any HTTP endpoint into a paid, discoverable x402 resource.
+
+For the mechanics of building and signing a payment, pair this with the companion [`x402`](../x402/) skill.
+
+## Install
+
+### Claude Code
+
+```bash
+mkdir -p ~/.claude/skills/payai
+cp -r SKILL.md scripts ~/.claude/skills/payai/
+```
+
+### OpenAI Codex
+
+```bash
+mkdir -p ~/.codex/skills/payai
+cp -r SKILL.md scripts ~/.codex/skills/payai/
+```
+
+### VS Code / GitHub Copilot
+
+```bash
+mkdir -p .github/skills/payai
+cp -r SKILL.md scripts .github/skills/payai/
+```
+
+Works with any agent that supports the [Agent Skills](https://agentskills.io) standard.
+
+## Try it (safe, no spend)
+
+`scripts/discover.mjs` lists live paid services from the PayAI Bazaar (zero dependencies, Node 18+):
+
+```bash
+node scripts/discover.mjs                  # recent resources
+node scripts/discover.mjs --network solana # only Solana-payable
+node scripts/discover.mjs --query weather  # filter by keyword
+```
+
+## Key details
+
+| Feature | Detail |
+|---|---|
+| Facilitator | `https://facilitator.payai.network` (no signup) |
+| Bazaar | `GET /discovery/resources` |
+| Chains | Solana + 9 EVM (Base, Polygon, Arbitrum, Avalanche, Sei, X Layer, SKALE) |
+| Asset | USDC (6 decimals) |
+| Solana gas | Paid by the facilitator |
+| Sell | `x402-express` / `x402-hono` / `x402-next` middleware |
+
+## Links
+
+- **Website:** https://payai.network
+- **Docs:** https://docs.payai.network
+- **Bazaar (live):** https://facilitator.payai.network/discovery/resources
+- **Supported networks (live):** https://facilitator.payai.network/supported
+- **Companion skill:** [`x402`](../x402/) — pay for any 402-gated resource
+- **Example consumer:** [`sp3nd`](../sp3nd/) — buy from Amazon with USDC via PayAI
+
+## License
+
+MIT

skills/payai/SKILL.md

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+---
+name: payai
+description: Discover, pay for, and sell agent services over the x402 protocol using the PayAI Network. Browse the PayAI Bazaar — a live directory of paid APIs and agent services — pay any of them autonomously with USDC on Solana or EVM chains via the open PayAI facilitator, and expose your own endpoints as x402-monetized resources so other agents pay you. Use when an agent needs to find a paid tool/API/service, settle an x402 payment across chains, or accept crypto payments for the work it does.
+metadata: {"openclaw":{"emoji":"🌐","homepage":"https://payai.network","primaryEnv":"SOLANA_PRIVATE_KEY"}}
+---
+
+# PayAI — The Payment Network for Autonomous Agents
+
+## What is PayAI?
+
+**PayAI** is an open payment network that lets AI agents **find, pay for, and sell** services to each other using the [x402 protocol](https://x402.gitbook.io/x402) — HTTP-native payments settled in stablecoins (USDC). It has three parts an agent cares about:
+
+1. **The facilitator** (`https://facilitator.payai.network`) — a neutral, no-signup service that **verifies** and **settles** x402 payments across many chains. It settles **Solana** (and pays the gas for you) and **9 EVM chains**.
+2. **The Bazaar** (`/discovery/resources`) — a live, queryable directory of paid x402 resources: APIs, tools, and agent services you can call and pay for right now.
+3. **Merchant support** — libraries and facilitator endpoints that let *your* agent price an endpoint in USDC and get paid by other agents.
+
+Think of PayAI as the marketplace + settlement layer. This skill covers **discovering** services and **selling** yours. For the mechanics of *constructing and signing a payment*, use the companion [`x402`](../x402/) skill.
+
+## When to use this skill
+
+- You need a capability (data, inference, a tool, a physical good) and want to **find an agent/API that sells it**.
+- You have an x402 payment to **verify or settle** and need a facilitator.
+- You want to know **which chains/assets** are supported before paying.
+- You want to **monetize** your own agent or API so other agents pay you in USDC.
+
+## Part 1 — Discover services (the Bazaar)
+
+Query the live directory of paid resources:
+
+```bash
+curl -s "https://facilitator.payai.network/discovery/resources?limit=25" | jq
+```
+
+The response is a paginated list of resources:
+
+```json
+{
+  "x402Version": 1,
+  "items": [
+    {
+      "resource": "https://tripadvisor.x402.paysponge.com/api/v1/location/:locationId/details",
+      "type": "http",
+      "method": "GET",
+      "x402Version": 2,
+      "accepts": [
+        {
+          "scheme": "exact",
+          "network": "eip155:8453",
+          "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
+          "payTo": "0x6302D9e6DBB22fEC3c350551568Bb39B4b35Ad57",
+          "amount": "10000",
+          "maxTimeoutSeconds": 300
+        }
+      ],
+      "inputSchema": { "type": "http", "method": "GET", "pathParams": { "locationId": "154943" } },
+      "outputSchema": { "type": "json", "example": {} },
+      "lastUpdated": "2026-07-24T05:18:11.665Z"
+    }
+  ],
+  "pagination": { "limit": 25, "offset": 0 }
+}
+```
+
+Each item tells you everything needed to call and pay for it:
+
+- **`resource`** — the URL to call (with `:param` path params described in `inputSchema`).
+- **`method`** — HTTP verb.
+- **`x402Version`** — the item's protocol version. **v2** items use CAIP-2 networks (`eip155:8453`, `solana:<genesis>`) and the `PAYMENT-SIGNATURE` header; **v1** items use plain names (`base`) and `X-PAYMENT`. (The discovery envelope's own `x402Version` is separate — read each item's.)
+- **`accepts`** — the same payment-requirements array you'd get from a `402` (network, asset, price, `payTo`).
+- **`inputSchema` / `outputSchema`** — how to call it and what comes back.
+
+### Workflow: find → pay → use
+
+1. **Search** the Bazaar for a resource that does what you need (filter `items` by keywords in `resource`, or by a `network`/asset you hold).
+2. **Read the price** from `accepts[].amount` (base units; USDC = 6 decimals).
+3. **Call + pay** using the [`x402`](../x402/) skill — send the request, get a `402`, build the payment, retry with the payment header (`X-PAYMENT` for v1, `PAYMENT-SIGNATURE` for v2 — matched to the item's `x402Version`).
+
+`scripts/discover.mjs` (zero dependencies, Node 18+) fetches the Bazaar and prints a readable table, with optional filtering:
+
+```bash
+node scripts/discover.mjs                 # list recent resources
+node scripts/discover.mjs --network solana # only Solana-payable resources
+node scripts/discover.mjs --query weather  # match resource URL/description
+```
+
+## Part 2 — The facilitator API
+
+Base URL: `https://facilitator.payai.network`. No API key, no signup.
+
+### `GET /supported` — which chains & schemes settle
+
+```bash
+curl -s https://facilitator.payai.network/supported | jq '.kinds[] | {scheme, network}'
+```
+
+Returns the authoritative list. Currently:
+
+| Chain | Networks | x402 versions |
+|---|---|---|
+| **Solana** | `solana`, `solana-devnet`, `solana:<genesis>` (v2) | v1 + v2 |
+| **Base** | `base`, `base-sepolia`, `eip155:8453` | v1 + v2 (incl. `upto`) |
+| **Polygon** | `polygon`, `polygon-amoy`, `eip155:137` | v1 + v2 |
+| **Arbitrum** | `arbitrum`, `arbitrum-sepolia`, `eip155:42161` | v1 + v2 |
+| **Avalanche** | `avalanche`, `avalanche-fuji`, `eip155:43114` | v1 + v2 |
+| **Sei** | `sei`, `sei-testnet`, `eip155:1329` | v1 + v2 |
+| **X Layer** | `xlayer`, `xlayer-testnet`, `eip155:196` | v1 + v2 |
+| **SKALE** | `skale-base`, `skale-base-sepolia` | v1 + v2 |
+
+On Solana, the facilitator is the **fee payer** — the payer spends only USDC, no SOL. Always trust the live `/supported` output over this table.
+
+### `POST /verify` — check a payment is valid (no settlement)
+
+```json
+POST /verify
+{ "paymentPayload": { … }, "paymentRequirements": { … } }
+→ { "isValid": true, "payer": "…" }
+```
+
+### `POST /settle` — broadcast/settle the payment on-chain
+
+```json
+POST /settle
+{ "paymentPayload": { … }, "paymentRequirements": { … } }
+→ { "success": true, "transaction": "<signature-or-hash>", "network": "solana", "payer": "…" }
+```
+
+Servers usually call `/verify` + `/settle` for you when you send the payment header (`X-PAYMENT` in v1, `PAYMENT-SIGNATURE` in v2). Some flows (e.g. the [`sp3nd`](../sp3nd/) skill in this repo) have the **client** call `/verify` then `/settle` directly. The payload shapes are defined by the [`x402`](../x402/) skill.
+
+## Part 3 — Sell your own services (get paid by agents)
+
+Any HTTP endpoint can become a paid, discoverable x402 resource:
+
+1. **Gate the route** so it returns `402 Payment Required` with an `accepts` array (your `scheme`, `network`, `payTo`, and price). The x402 server middlewares make this a few lines: **v2** — `@x402/express`, `@x402/hono`, `@x402/next` (built on `@x402/core` + a scheme from `@x402/evm` / `@x402/svm`); **v1** — `x402-express`, `x402-hono`, `x402-next`.
+2. **Settle** incoming payments via the PayAI facilitator — point the middleware's facilitator client at `https://facilitator.payai.network` and it calls `/verify` + `/settle` for you.
+3. **Get discovered** — to appear in the Bazaar (`/discovery/resources`), a **v2** route must declare the discovery extension with `declareDiscoveryExtension()` from `@x402/extensions/bazaar` (hand-rolling `extensions.bazaar.schema` passes through but **fails silently** in the discovery crawler). See the seller guide at https://docs.payai.network.
+
+Conceptually, a v2 Express seller settled by PayAI:
+
+```javascript
+// npm i @x402/express @x402/core @x402/evm
+import express from "express";
+import { paymentMiddleware } from "@x402/express";
+import { x402ResourceServer, HTTPFacilitatorClient } from "@x402/core/server";
+import { ExactEvmScheme } from "@x402/evm/exact/server";
+
+const app = express();
+const payTo = "0xYourWallet";
+
+const facilitator = new HTTPFacilitatorClient({ url: "https://facilitator.payai.network" }); // PayAI settles
+const server = new x402ResourceServer(facilitator);
+server.register("eip155:*", new ExactEvmScheme());   // add ExactSvmScheme from @x402/svm for Solana
+
+app.use(paymentMiddleware(
+  {
+    "GET /premium": {
+      accepts: [{ scheme: "exact", price: "$0.01", network: "eip155:8453", payTo }], // CAIP-2
+      description: "Premium content",
+      mimeType: "application/json",
+    },
+  },
+  server,
+));
+app.get("/premium", (_req, res) => res.json({ data: "🎁 paid content" }));
+app.listen(3000);
+```
+
+> Confirm exact signatures against the x402 docs (https://x402.gitbook.io/x402) and PayAI's seller docs — config formats evolve. Start on a testnet (`base-sepolia`, `solana-devnet`).
+
+## A real consumer in this repo
+
+The [`sp3nd`](../sp3nd/) skill (buy from Amazon with USDC) settles every order through the **PayAI facilitator** on **Solana** — a working example of x402 + PayAI end to end.
+
+## Key facts
+
+- **Facilitator:** `https://facilitator.payai.network` — no signup, multi-chain.
+- **Bazaar / discovery:** `GET /discovery/resources` (paginated `items[]`).
+- **Verify / settle:** `POST /verify`, `POST /settle` with `{ paymentPayload, paymentRequirements }`.
+- **Supported:** `GET /supported` — Solana (+ gas paid for you) and 9 EVM chains.
+- **Asset:** USDC, 6 decimals. Solana mint `EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v`; Base contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`.
+- **Pay mechanics + v1/v2 headers:** see the [`x402`](../x402/) skill (v2 uses `PAYMENT-SIGNATURE` / `PAYMENT-RESPONSE`; v1 uses `X-PAYMENT` / `X-PAYMENT-RESPONSE`).
+- **Seller middlewares:** v2 — `@x402/express`, `@x402/hono`, `@x402/next` (+ `@x402/extensions/bazaar` for discovery); v1 — `x402-express`, `x402-hono`, `x402-next`.
+- **Website:** https://payai.network · **Docs:** https://docs.payai.network

skills/payai/_meta.json

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+{
+  "owner": "PayAINetwork",
+  "slug": "payai",
+  "displayName": "PayAI — Payment Network for Agents",
+  "latest": {
+    "version": "1.0.0",
+    "publishedAt": 1784871635427
+  },
+  "history": []
+}

skills/payai/scripts/discover.mjs

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+#!/usr/bin/env node
+// discover.mjs — Browse the PayAI Bazaar: live x402 paid resources you can call.
+//
+// Usage:
+//   node discover.mjs [--network <name>] [--query <text>] [--limit <n>] [--json]
+//
+// Examples:
+//   node discover.mjs                     # recent resources
+//   node discover.mjs --network solana    # only resources payable on Solana
+//   node discover.mjs --query weather     # match resource URL / description
+//
+// Zero dependencies — requires Node 18+ (global fetch).
+
+const FACILITATOR = process.env.PAYAI_FACILITATOR || "https://facilitator.payai.network";
+
+const args = process.argv.slice(2);
+let network, query, limit = 25, asJson = false;
+for (let i = 0; i < args.length; i++) {
+  if (args[i] === "--network") network = (args[++i] || "").toLowerCase();
+  else if (args[i] === "--query") query = (args[++i] || "").toLowerCase();
+  else if (args[i] === "--limit") limit = Number(args[++i]) || 25;
+  else if (args[i] === "--json") asJson = true;
+  else if (args[i] === "-h" || args[i] === "--help") {
+    console.log("Usage: node discover.mjs [--network <name>] [--query <text>] [--limit <n>] [--json]");
+    process.exit(0);
+  }
+}
+
+const ASSETS = {
+  EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v: { symbol: "USDC", decimals: 6 },
+  "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913":  { symbol: "USDC", decimals: 6 },
+};
+const assetInfo = a => ASSETS[a] || ASSETS[String(a).toLowerCase()] || { symbol: "token", decimals: 6 };
+
+function human(baseUnits, decimals) {
+  try {
+    const n = BigInt(baseUnits), d = BigInt(10) ** BigInt(decimals);
+    const frac = (n % d).toString().padStart(decimals, "0").replace(/0+$/, "");
+    return frac ? `${n / d}.${frac}` : `${n / d}`;
+  } catch { return String(baseUnits); }
+}
+
+const res = await fetch(`${FACILITATOR}/discovery/resources?limit=${Math.max(limit * 3, 50)}`);
+if (!res.ok) {
+  console.error(`Failed to reach Bazaar: HTTP ${res.status} ${res.statusText}`);
+  process.exit(1);
+}
+const data = await res.json();
+let items = data.items || [];
+
+if (network) items = items.filter(it => (it.accepts || []).some(a => String(a.network).toLowerCase().includes(network)));
+if (query)   items = items.filter(it => JSON.stringify(it).toLowerCase().includes(query));
+items = items.slice(0, limit);
+
+if (asJson) { console.log(JSON.stringify(items, null, 2)); process.exit(0); }
+
+console.log(`\nPayAI Bazaar — ${items.length} resource(s)  (facilitator: ${FACILITATOR})`);
+if (network) console.log(`filter: network~="${network}"`);
+if (query)   console.log(`filter: query~="${query}"`);
+
+for (const it of items) {
+  const opts = (it.accepts || []).map(a => {
+    const info = assetInfo(a.asset);
+    const amt = a.maxAmountRequired ?? a.amount;
+    return `${human(amt, info.decimals)} ${info.symbol} on ${a.network}`;
+  });
+  console.log(`\n• ${it.method || "GET"} ${it.resource}`);
+  if (it.accepts?.[0]?.description) console.log(`  ${it.accepts[0].description}`);
+  console.log(`  pay: ${opts.join("  |  ") || "(no accepts listed)"}`);
+  if (it.accepts?.[0]?.payTo) console.log(`  payTo: ${it.accepts[0].payTo}`);
+}
+
+console.log(`\nTo call + pay one of these, use the companion \`x402\` skill.`);