X Data Api

import { wrapFetchWithPayment } from "x402-fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";

const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: base, transport: http() });
const fetch = wrapFetchWithPayment(globalThis.fetch, wallet);

// Fetch a tweet — payment handled automatically
const res = await fetch("https://metar.api/api/x/tweet/1234567890");
const tweet = await res.json();
console.log(tweet);

Option 2: Metar SDK (Solana native)

npm install @metar/metar-client

import { MetarClient, createNodeWallet } from "@metar/metar-client";
import { createConnection } from "@metar/shared-config";
import { Keypair } from "@solana/web3.js";

const keypair = Keypair.fromSecretKey(Buffer.from(process.env.WALLET_PRIVATE_KEY!, "base64"));
const wallet = createNodeWallet(keypair);
const connection = createConnection("mainnet");

const client = new MetarClient({
  providerBaseURL: "https://metar.api",
  agentKeyId: "my-agent",
  agentPrivateKey: keypair.secretKey,
  wallet,
  connection,
  chain: "solana",
});

const response = await client.request("tweet:lookup", {
  method: "GET",
  headers: { "x-tweet-id": "1234567890" },
});
const tweet = await response.json();

Option 3: Run the installer

curl -fsSL https://metar.api/api/skill/install.sh | bash

Why Use This?

Built for:

• 🤖 AI agents and autonomous systems
• ⚡ Serverless functions and edge compute
• 🔁 Batch processing pipelines
• 🛠️ Developer scripts and prototypes
• 🔗 Microservices with usage-based billing

Supported Chains

Solana (Primary)

• Token: USDC (EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v)
• Speed: ~400ms finality
• Cost: ~$0.00025 per transaction fee
• Networks: solana (mainnet), solana-devnet
• Packages: @metar/metar-client, x402-solana

Base (EVM)

• Token: USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)
• Speed: ~2s finality
• Cost: ~$0.001 per transaction fee
• Network: base
• Packages: x402-fetch, viem

Ethereum (EVM)

• Token: USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48)
• Speed: ~12s finality
• Cost: ~$0.50+ per transaction fee (use Base for cheaper fees)
• Network: ethereum
• Packages: x402-fetch, viem

Auth Modes

x402-TAP (Solana native)

Uses Visa's Trusted Agent Protocol (TAP) — a stateless, cryptographic identity system for agents:

• Ed25519 keypair signs every request
• No sessions, no tokens, no state
• Works in serverless, edge, and distributed systems
• Replay-attack resistant (nonces + timestamps)

Authorization: Signature keyId="<agentId>", alg="ed25519", headers="(request-target) date x-meter-nonce x-meter-tx", signature="<base64>"

x402-fetch (EVM chains)

Standard x402 protocol via x402-fetch package:

• EIP-712 signed payment authorization
• Works with any EVM wallet (viem, ethers, wagmi)
• No custom headers — just wrap fetch

All Routes + Prices

Tweet Endpoints

User Endpoints

List Endpoints

Trending / Discovery

Meta Endpoints (free)

Code Examples

Solana — Fetch User Profile

import { MetarClient, createNodeWallet } from "@metar/metar-client";
import { createConnection } from "@metar/shared-config";
import { Keypair } from "@solana/web3.js";

async function getUserProfile(username: string) {
  const keypair = Keypair.fromSecretKey(
    Buffer.from(process.env.WALLET_PRIVATE_KEY!, "base64")
  );
  const wallet = createNodeWallet(keypair);
  const connection = createConnection("mainnet");

  const client = new MetarClient({
    providerBaseURL: "https://metar.api",
    agentKeyId: "my-agent-v1",
    agentPrivateKey: keypair.secretKey,
    wallet,
    connection,
    chain: "solana",
  });

  // Automatically fetches price, pays, and requests
  const response = await client.request("user:lookup", {
    method: "GET",
    // Route maps to /api/x/user/:username
    headers: { "x-username": username },
  });

  return response.json();
}

const user = await getUserProfile("elonmusk");
console.log(user.data.name, user.data.public_metrics.followers_count);

Base (EVM) — Search Recent Tweets

import { wrapFetchWithPayment } from "x402-fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";

const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: base, transport: http() });
const fetch = wrapFetchWithPayment(globalThis.fetch, wallet);

const query = encodeURIComponent("AI agents lang:en -is:retweet");
const res = await fetch(`https://metar.api/api/x/search/recent?query=${query}&max_results=10`);
const data = await res.json();

for (const tweet of data.data) {
  console.log(`@${tweet.author_id}: ${tweet.text}`);
}

Ethereum — Get User Timeline

import { wrapFetchWithPayment } from "x402-fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { mainnet } from "viem/chains";

const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: mainnet, transport: http() });
const fetch = wrapFetchWithPayment(globalThis.fetch, wallet);

// Get @vitalikbuterin's timeline
const res = await fetch("https://metar.api/api/x/user/44196397/tweets?max_results=20");
const timeline = await res.json();

timeline.data.forEach((tweet: any) => {
  console.log(tweet.text, "\n---");
});

Solana Devnet — Testing

import { MetarClient, createNodeWallet } from "@metar/metar-client";
import { createConnection } from "@metar/shared-config";
import { Keypair } from "@solana/web3.js";

// Use devnet for testing — free devnet USDC airdrop available
const keypair = Keypair.generate(); // or load from file
const wallet = createNodeWallet(keypair);
const connection = createConnection("devnet");

const client = new MetarClient({
  providerBaseURL: "https://metar.api",
  agentKeyId: `test-agent-${Date.now()}`,
  agentPrivateKey: keypair.secretKey,
  wallet,
  connection,
  chain: "solana-devnet",
});

// Get price before paying
const priceRes = await fetch("https://metar.api/.meter/price?route=tweet:lookup");
const price = await priceRes.json();
console.log(`Tweet lookup costs ${price.price} ${price.currency}`);

Batch Processing — Analyze 100 Tweets

import { wrapFetchWithPayment } from "x402-fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";

const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const wallet = createWalletClient({ account, chain: base, transport: http() });
const fetch = wrapFetchWithPayment(globalThis.fetch, wallet);

const tweetIds = [
  "1234567890", "1234567891", "1234567892",
  // ... up to 100
];

// Single payment covers the batch
const res = await fetch("https://metar.api/api/x/tweets", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ ids: tweetIds }),
});

const { data } = await res.json();
console.log(`Fetched ${data.length} tweets for $0.008 USDC`);

Troubleshooting

402 Payment Required on every request

• Your wallet has insufficient USDC balance
• Check balance: connect to Solana devnet/mainnet and verify USDC token account
• For devnet testing, use a USDC faucet

Payment verification failed

• Timestamp drift: ensure your system clock is accurate (NTP sync recommended)
• Nonce reuse: nonces must be unique per request (UUID v7 recommended)
• Wrong recipient: payment must go to the address returned by /.meter/price

TAP signature invalid

• Ensure agentPrivateKey matches the registered agentKeyId
• Don't share keypairs across multiple agent instances with different IDs
• Check that the signature covers the correct headers (request-target, date, nonce, tx)

Route not found

• Verify the route ID exactly matches the table above (case-sensitive)
• Check /api/pricing for a complete, up-to-date route list

EVM: Insufficient funds

• USDC balance must cover the route price + gas fees on Base/Ethereum
• Use Base for 100x cheaper gas vs Ethereum mainnet

Connection timeouts

• Check network connectivity to Solana RPC
• Consider using a private RPC (Helius, Triton, Alchemy) for production
• Default public RPC may rate-limit under high load

Need help?

• Service status: GET https://metar.api/api/info
• Full pricing: GET https://metar.api/api/pricing
• Trust manifest: GET https://metar.api/.well-known/trust.json