I Added x402 Payments to Base’s Agent Skills — Here’s How

If you build agents on Base, two things landed recently that are worth connecting.

First: Base shipped its own Agent Skills. There’s now a base/skills repo with consolidated skills that teach an AI agent to connect to Base, deploy contracts, authenticate wallets, and run nodes — installed with one command via Vercel’s npx skills CLI.

Second: that CLI is part of a fast-growing, cross-agent ecosystem most crypto devs haven’t clocked yet. So this post does two things — explains how npx skills and skills.sh actually work, and shows where the payment layer in Base’s skills stops and how to extend it with x402 pay-per-call and batch disbursement.

What npx skills actually is

npx skills is an open CLI from Vercel Labs for installing “skills” — modular SKILL.md files that teach an agent a specific capability without stuffing everything into its context window. A few things make it different from what crypto devs usually expect:

• GitHub is the registry. There’s no central package server. Any public GitHub repo with a SKILL.md at its root is a valid, installable skill. Install with npx skills add owner/repo.
• It’s cross-agent. The same skill installs into Claude Code, Cursor, Codex, GitHub Copilot, Goose, Windsurf, Gemini, and dozens more. You write once; it works across the agent you (or your users) actually run.
• skills.sh is the directory + leaderboard. It ranks skills by real install counts pulled from telemetry, with all-time, trending, and hot lists. There’s no editorial submission step — you publish by putting a skill in a repo, and installs surface it.

The format underneath — SKILL.md — is an open spec, which is why Base, Vercel, Anthropic, and a long tail of independent devs all use the same files.

Here’s Base’s install, for reference:

# Base's official agent skills
npx skills add base/skills --skill build-on-base
npx skills add base/skills --skill base-mcp

build-on-base is a consolidated Base dev playbook; base-mcp wires up a Base MCP server that gives an agent a wallet — sending, swapping, signing, batched calls, balances.

Where Base’s skills stop

This is the interesting gap. Base’s skills give an agent a wallet and the ability to transact: send a payment, swap a token, sign, batch several calls into one transaction. That’s the on-chain action layer, and it’s well covered.

What that layer doesn’t do is two distinct things the agent economy actually runs on:

1. Pay-per-call consumption. When an agent needs to buy data or compute — a price feed, a web search, an LLM completion — it needs to pay for that call, per call, without an API key or a billing account. That’s x402: the HTTP 402 “Payment Required” status code turned into a machine-readable micropayment handshake. The agent hits an endpoint, gets a 402 with a price, signs a USDC authorization, retries, and gets the data. No signup.

2. Batch disbursement. “Batched calls” (bundling operations into one tx) is not the same as paying many different recipients in one transaction — payroll, airdrops, contributor payouts, refunds. That’s a disbursement primitive, and it’s what the Batch Payments for Agents (BPA 1.0) spec standardizes.

Both settle in USDC on Base. Neither is something a wallet-only skill handles. So they’re a clean, complementary layer to drop on top of what Base ships.

Adding the payment layer

I published three skills that fill exactly that gap, each its own repo so you install only what you need:

• defi-intelligence-x402 — pay-per-call data + market intelligence on Base (prices, oracles, swap quotes, wallet analytics, ENS/Basename)
• ai-compute-x402 — pay-per-call AI inference (200+ LLMs, Bittensor, image gen, embeddings, GPU)
• agent-payments-x402 — batch payments, payroll, invoicing, escrow (BPA 1.0)

# Pay-per-call data + market intelligence on Base
npx skills add plagtech/defi-intelligence-x402

# Pay-per-call AI inference (200+ LLMs, Bittensor, GPU)
npx skills add plagtech/ai-compute-x402

# Batch payments, payroll, invoicing, escrow (BPA 1.0)
npx skills add plagtech/agent-payments-x402

All three call the Spraay x402 Gateway, which is x402-native end to end — no API keys, no accounts. You fund a wallet with USDC on Base, set one env var, and the x402 client signs and retries payments automatically.

npm install x402-client
export EVM_PRIVATE_KEY=0x...   # wallet holding USDC on Base

Worked example: an agent that prices before it acts

A read call costs a fraction of a cent and needs no key:

import { createClient } from "x402-client";

const client = createClient({
  baseUrl: "https://gateway.spraay.app",
  privateKey: process.env.EVM_PRIVATE_KEY,
});

// Live oracle prices — pays ~$0.008 USDC, automatically
const prices = await client.get("/api/v1/oracle/prices");
// { ETH: 2847.50, BTC: ... }

// Profile a wallet before interacting with it
const profile = await client.get("/api/v1/analytics/wallet?address=0xabc...");

Worked example: pay 50 people in one transaction

This is the disbursement primitive a wallet-only skill can’t express:

// Batch-send USDC to many recipients in a single tx
const tx = await client.post("/api/v1/batch/execute", {
  chain: "base",
  token: "USDC",
  recipients: [
    { address: "0xabc...", amount: "10.00" },
    { address: "0xdef...", amount: "25.50" },
    // ...up to your full roster
  ],
});

Estimate first with /api/v1/batch/estimate (≈$0.001) if you want a gas/fee preview before sending.

Why this matters for agents on Base

The mental model is two layers:

• Base’s skills = the agent has a wallet and can transact.
• x402 skills = the agent can pay for each call it makes, and pay many parties at once.

Put them together and you have an agent that can read on-chain state, buy the data and compute it needs per call, and disburse funds — all in USDC on Base, all without a single API key or account. That’s most of what an autonomous economic agent actually needs to do a job end to end.

If you’re building on Base, the install lines above are the fastest way to try the payment layer. Skills are just SKILL.md files — open them before you install (it takes 30 seconds) and you’ll see exactly which endpoints get called and what they cost.

Skills: agent-payments-x402 · defi-intelligence-x402 · ai-compute-x402

Links: Spraay Gateway · Docs / full endpoint catalog · Live gateway traffic · BPA 1.0 spec