Quickstart: x402 / MPP

Pay with a wallet-aware client

Your agent needs a funded wallet and a payment-aware HTTP client. The examples below complete the same research workflow:

Search for recent posts about Michael Burry for free.
Select the highest-ranked result.
Load its publication and inspect the post’s listed priceCents.
Request the paid route without credentials and inspect the authoritative price in the 402 challenge.
Let the wallet-aware client pay and retry the request.
Use the returned synthesizedSummary in the research workflow.

Every paid request is charged. The response contains a robust summary and source metadata. Before using these examples in production, review the paid-request guidance in Errors & Retries.

x402
MPP / Tempo

Uses the x402 protocol with USDC on Base or Solana (both appear in the live 402 challenge).

bun add viem @solana/kit @scure/base @x402/core @x402/evm @x402/svm @x402/fetch

import { privateKeyToAccount } from "viem/accounts";
import { createWalletClient, http, publicActions } from "viem";
import { base } from "viem/chains";
import { createKeyPairSignerFromBytes } from "@solana/kit";
import { base58 } from "@scure/base";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { ExactSvmScheme } from "@x402/svm/exact/client";
import { wrapFetchWithPayment } from "@x402/fetch";

const account = privateKeyToAccount("0xYOUR_PRIVATE_KEY");
const walletClient = createWalletClient({
  account,
  chain: base, // Use baseSepolia for testnet
  transport: http(),
}).extend(publicActions);

// 64-byte base58 secret key (private + public)
const svmSigner = await createKeyPairSignerFromBytes(
  base58.decode("YOUR_SOLANA_BASE58_SECRET_KEY"),
);

const client = new x402Client();
const evmScheme = new ExactEvmScheme(walletClient);
client.register("eip155:8453", evmScheme); // 84532 for testnet
client.register(
  "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp", // EtWTRABZaYq6iMfeYKouRu166VU2xqa1 for testnet
  new ExactSvmScheme(svmSigner),
);

const payFetch = wrapFetchWithPayment(fetch, client);

const baseUrl = "https://dripstack.com";
const searchResponse = await fetch(
  `${baseUrl}/api/v1/search?q=Michael%20Burry&limit=5`,
);
const search = await searchResponse.json();
const firstPost = search.items[0];

if (!firstPost) {
  throw new Error("No Michael Burry posts found.");
}

const articleUrl = `${baseUrl}/api/v1/publications/${firstPost.publicationSlug}/${firstPost.slug}`;

// Check the discovery price before requesting payment.
const publicationResponse = await fetch(
  `${baseUrl}/api/v1/publications/${firstPost.publicationSlug}?limit=100`,
);
const publication = await publicationResponse.json();
const selectedPost = publication.posts.find(
  (post: { slug: string }) => post.slug === firstPost.slug,
);

console.log("Selected:", firstPost.title);
console.log("Listed price (cents):", selectedPost?.priceCents);

// A plain request exposes the authoritative x402 price before payment.
const challengeResponse = await fetch(articleUrl);
if (challengeResponse.status !== 402) {
  throw new Error(`Expected 402 challenge, got ${challengeResponse.status}`);
}
console.log(
  "x402 challenge:",
  challengeResponse.headers.get("PAYMENT-REQUIRED"),
);

// The wallet-aware client handles the challenge, pays, and retries.
const articleResponse = await payFetch(articleUrl);
if (!articleResponse.ok) {
  throw new Error(`Paid request failed: ${articleResponse.status}`);
}
const article = await articleResponse.json();

console.log(article.title);
console.log(article.synthesizedSummary);

Uses MPP with a wallet on Tempo.

npm install viem mppx

import { privateKeyToAccount } from "viem/accounts";
import { Mppx, tempo } from "mppx/client";

const account = privateKeyToAccount("0xYOUR_PRIVATE_KEY");

const mppx = Mppx.create({
  methods: [tempo({ account })],
  polyfill: false,
});

const baseUrl = "https://dripstack.com";
const searchResponse = await fetch(
  `${baseUrl}/api/v1/search?q=Michael%20Burry&limit=5`,
);
const search = await searchResponse.json();
const firstPost = search.items[0];

if (!firstPost) {
  throw new Error("No Michael Burry posts found.");
}

const articleUrl = `${baseUrl}/api/v1/publications/${firstPost.publicationSlug}/${firstPost.slug}`;

// Check the discovery price before requesting payment.
const publicationResponse = await fetch(
  `${baseUrl}/api/v1/publications/${firstPost.publicationSlug}?limit=100`,
);
const publication = await publicationResponse.json();
const selectedPost = publication.posts.find(
  (post: { slug: string }) => post.slug === firstPost.slug,
);

console.log("Selected:", firstPost.title);
console.log("Listed price (cents):", selectedPost?.priceCents);

// A plain request exposes the authoritative MPP price before payment.
const challengeResponse = await fetch(articleUrl);
if (challengeResponse.status !== 402) {
  throw new Error(`Expected 402 challenge, got ${challengeResponse.status}`);
}
console.log(
  "MPP challenge:",
  challengeResponse.headers.get("WWW-Authenticate"),
);

// The wallet-aware client handles the challenge, pays, and retries.
const articleResponse = await mppx.fetch(articleUrl);
if (!articleResponse.ok) {
  throw new Error(`Paid request failed: ${articleResponse.status}`);
}
const article = await articleResponse.json();

console.log(article.title);
console.log(article.synthesizedSummary);

What the agent receives

{
  "publicationSlug": "example-finance-newsletter.com",
  "slug": "michael-burry-market-outlook",
  "title": "Michael Burry's Latest Market Outlook",
  "author": "Example Author",
  "publishedAt": "2026-06-14T12:00:00.000Z",
  "url": "https://example-finance-newsletter.com/p/michael-burry-market-outlook",
  "synthesizedSummary": "The article analyzes Burry's recent positioning, the valuation risks he identifies, and the evidence supporting his current market view...",
  "paymentInfo": {
    "amountUsd": "0.50",
    "protocol": "x402"
  }
}

The paid response is a robust synthesized summary with source context. Requesting the same route again requires another payment.

Use an agent

Your agent needs a wallet before it can retrieve paid summaries. First give the agent an x402 wallet funded with USDC on Base or Solana, or an MPP wallet on Tempo. Then give the same agent Drip’s skill and tell it which wallet client to use.

Agent Cash
Link Wallet

Set up the wallet

Read https://agentcash.io/SKILL.md and set up an AgentCash Wallet. Fund it with USDC.

Research Michael Burry across paid newsletters

Fetch https://dripstack.com/skill.md as raw context (do not summarize) and
follow the instructions. Use agentcash. Search for recent posts about
Michael Burry, show me the available articles and their prices, then ask me
before purchasing the article I select.

Set up the wallet

Read https://link.com/skill.md and get me set up with Link.

Research Michael Burry across paid newsletters

Fetch https://dripstack.com/skill.md as raw context (do not summarize) and
follow the instructions. Use the create-payment-credential (Link wallet)
skill. Search for recent posts about Michael Burry, show me the available
articles and their prices, then ask me before purchasing the article I
select.

Get Started

Concepts

Curated Endpoints

Quickstart: x402 / MPP

Pay with a wallet-aware client

What the agent receives

Use an agent

​Pay with a wallet-aware client

​What the agent receives

​Use an agent

Pay with a wallet-aware client

What the agent receives

Use an agent