Agent integration

1. Find what to buy

Fetch the master manifest. No auth, no payment required. Returns every skill, hosted API, and paid content endpoint with x402 metadata.

curl https://mondello.dev/api/catalog.json

Each item includes an x402 block with scheme, network, asset, payTo, priceMicroUsd — everything needed to pay programmatically.

2. OpenAPI for function calling

If your agent supports OpenAPI (Claude tool use, ChatGPT function calling, LangChain, etc.), skip straight to the spec:

curl https://mondello.dev/openapi.json

It's a valid OpenAPI 3.1 document with one custom extension — x-x402-payment — that tells the client how much a given operation costs and where to pay. The rest of the spec (paths, request schemas, response shapes) is fully standard, so most OpenAPI-aware tools can import it with no changes.

3. MCP server

Every EmDash site ships an MCP server over Streamable HTTP at /_emdash/api/mcp. Tools: content read/search, schema introspection, media, menus, taxonomy.

# Unauthenticated probe — returns 401 with WWW-Authenticate
curl -i https://mondello.dev/_emdash/api/mcp

# Auth discovery
curl https://mondello.dev/.well-known/oauth-protected-resource

Auth is OAuth 2.1 with dynamic client registration — point Claude Desktop, Cursor, or any MCP-aware tool at the URL and the flow is automatic. This is separate from x402: MCP is for site content read; x402 is for paid compute.

4. Pay with curl

The server returns HTTP 402 with a PAYMENT-REQUIRED header describing what's owed. Any x402-compatible wallet tool can sign the challenge and retry:

# Step 1: get the 402 challenge
curl -i https://mondello.dev/skills/emdash-deploy/raw

# Step 2: decode the challenge header, sign with your wallet,
# retry with the payment-signature header. Any x402 client
# (e.g. 'npx @x402/cli pay <url>') handles this for you.

Resources without needing a wallet: /skills/<slug> preview pages, /skills.json, /api/catalog.json, /api/stats.json, /api/x402/media/image/generate?inspect=1 style landing docs on every paid endpoint.

5. Pay from TypeScript

We publish a small helper at src/lib/x402-client.ts that wraps fetch() with the full x402 handshake. Any Cloudflare Worker, Node script, or Astro SSR can use it:

import { privateKeyToAccount } from "viem/accounts";
import { x402FetchBytes } from "@/lib/x402-client";

const signer = privateKeyToAccount(process.env.WALLET_PK);

const { bytes, paid, paidUsd } = await x402FetchBytes(
  "https://mondello.dev/api/x402/media/image/generate",
  {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ title: "an agent-era hero" }),
    signer,
    maxPriceUsd: 0.10,        // refuse anything above $0.10
    allowedNetworks: ["eip155:8453"], // Base only
  },
);

console.log(`Paid ${paidUsd} USDC, got ${bytes.length} byte image`);

The helper caps single-payment size, restricts networks + asset, and only retries once. See the source for the full API.

6. Use from Claude Code

Any Claude Code skill installed from this site is a pure Markdown recipe — no runtime payment needed after install. The paid step is the initial download:

curl -sSL https://mondello.dev/skills/emdash-deploy/install | bash

The install script fetches the x402-gated raw markdown and writes to ~/.claude/skills/<slug>/skill.md. If the agent shell has x402 configured it pays silently; otherwise you get clear instructions on stdout.

7. Fund a wallet

x402 today settles in USDC on Base mainnet. Minimum practical funding is a few dollars. Base bridge: bridge.base.org. For agents that already hold USDC on Ethereum mainnet, the native Base bridge is cheapest. For fresh wallets, Coinbase can send USDC directly to Base with no gas hassle.

Our treasury wallet: 0x0E4d1C7Ca47879C7Dd518526ef38f290C7081028 on Base. This is the payTo value in every x402 challenge from this site. You can verify settlements on BaseScan.