DevX Multichain Balances

One call, nine chains. Native coin plus the major tokens for an address on Base, Ethereum, Arbitrum, Optimism, Polygon, Avalanche, BNB Chain, Solana and Tron. It is built for AI agents and apps that need to answer "what does this wallet hold?" without running their own RPC setup.

Everything here is read-only. It never asks for keys and never moves funds.

Live: https://wallet-balances.nextill-pos.workers.dev · token list: /tokens.json

CLI

npx devx-multichain-balances 9WzDXwBbmkg8ZTbNMqUxvQRAyrZzDsGYdLVL9zYtAWWM          # free: SOL + USDC on Solana
npx devx-multichain-balances TNXoiAJ3dct8Fjg4M9fkLFh9S2v9TXc32G                      # free: TRX + USDT on Tron
npx devx-multichain-balances 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 --chain arbitrum   # free: ETH + USDC on Arbitrum

# paid, 0.002 USDC per call: every matching chain, all majors, custom tokens
export X402_PRIVATE_KEY=0x...   # a Base wallet holding a little USDC (use a dedicated low-balance wallet)
npx devx-multichain-balances all 0xd8dA...6045,9WzD...AWWM --chains base,ethereum,solana

How paying works: the CLI asks the API for its x402 quote, checks that it is USDC on Base, goes to 0xB3cD…f247 and is at or under --max-usd (default 0.01), then signs a gasless EIP-3009 authorization with your key via @x402/fetch. The key stays on your machine. Without a key, all prints the quote, pays nothing and exits with code 2. Since v2.0.0 the package is a thin client. It no longer ships the balance-reading code, and the addresses you query are sent to the hosted API.

Related MCP server: chain-data

MCP

Claude Desktop / Cursor (stdio):

{ "mcpServers": { "multichain-balances": { "command": "npx", "args": ["-y", "devx-multichain-balances", "mcp"], "env": { "X402_PRIVATE_KEY": "0x... (optional, enables the paid tool)" } } } }

Or remote (streamable HTTP): https://wallet-balances.nextill-pos.workers.dev/mcp (free tool + info only)

Tools: basic_balance (free), multichain_balances (0.002 USDC per call, pays only if X402_PRIVATE_KEY is set and never above 0.01 USDC, otherwise returns the quote), multichain_balances_info.

Paid hosted call (x402)

GET https://wallet-balances.nextill-pos.workers.dev/v1/balances?address=0x...,<solana>,<T...>[&chains=base,ethereum,solana,tron][&tokens=base:0xToken,solana:<mint>,tron:<T...>]

• Answers 402 with an x402 v1 body (X-PAYMENT, network base) and a v2 PAYMENT-REQUIRED header (PAYMENT-SIGNATURE, eip155:8453). Both work. POST with a JSON body works too.

• 2000 atomic USDC (0.002 USDC) to 0xB3cDDccEe6B150c8efFD55B961afc0Ecefe7f247, settled through the Coinbase CDP facilitator, listed in the CDP x402 Bazaar.

• Settled only after a result is produced. Bad input, or every chain's RPC failing, is not charged. Failed chains are listed in summary.chains_failed.

• chains defaults to every chain that matches the addresses you gave (evm = the 7 EVM chains).

Limits

• It does not discover arbitrary tokens. It checks a fixed, verified list (see /tokens.json), and you can pass extra tokens yourself.

• On Solana it reads the owner's associated token accounts (where wallets normally keep tokens). Tokens held in other token accounts are not counted.

• The stablecoin total is face value (1 token = 1 unit), not a market price.

• Data comes from free public RPC nodes (publicnode.com with fallbacks: mainnet-beta / Tatum gateway for Solana, TronGrid for Tron). Identical calls within 20 s may be served from a short per-instance cache (cache.hit).

OpenAPI: /openapi.json · Terms: /terms

Related DevX tools

• Address Poisoning Check: is the recipient a lookalike of an address you trust?

• 7702 Sweeper Check: is an EIP-7702 sweeper delegation set on a wallet?

• Crypto Link Check: is a crypto URL a phishing / drainer lookalike?

Layout

• cli/: npm package devx-multichain-balances (CLI + stdio MCP client for the hosted API), npm test

• worker/: the Cloudflare Worker behind the hosted API (npm run build, npm test)

MIT. Made by DevX · madebydevx@gmail.com