Address Poisoning Check

Address Poisoning Check

Is this the address you meant? Address poisoning plants a lookalike address (same first and last characters, different middle) in a wallet's history with a zero-value, dust or fake-token transfer, and waits for the owner (or their AI agent) to copy it. Bitquery counted about $76M stolen on Ethereum alone in the 12 months to July 2026.

This repo has three pieces, all read-only (we never ask for keys and never move funds):

	What	Cost
CLI / stdio MCP devx-address-poisoning-check	Offline: is the recipient a lookalike of any address you trust? Is its EIP-55 checksum valid? Nothing leaves your machine.	free
Remote MCP https://address-poisoning-check.nextill-pos.workers.dev/mcp	Same offline check as a hosted MCP tool	free
HTTP API GET /v1/check?from=<sender>&to=<recipient>	On-chain: scans the sender's real transfer history (Ethereum + Base, optional Avalanche) and flags lookalikes of real counterparties, zero-value / dust / fake-token poisoning transfers (with tx hashes), recipients that only ever appeared through such transfers, and senders that were already poisoned. Returns ok | caution | danger and the address you probably meant.	0.005 USDC via x402 on Base

Live: https://address-poisoning-check.nextill-pos.workers.dev

CLI

npx devx-address-poisoning-check 0xd9A1C3788D81257612E2581A6ea0aDa244853a91 --known 0xd9A1b0B1e1aE382DbDc898Ea68012FfcB2853a91
# DANGER: Looks like 0xd9a1...3a91 (same first 4 / last 6 hex chars) but is a different address. Classic address-poisoning lookalike.

Exit code 2 on danger, so it can gate scripts and agent payment flows.

MCP

Claude Desktop / Cursor (stdio):

{ "mcpServers": { "address-poisoning-check": { "command": "npx", "args": ["-y", "devx-address-poisoning-check", "mcp"] } } }

Or remote (streamable HTTP): https://address-poisoning-check.nextill-pos.workers.dev/mcp

Tools: check_recipient_lookalike (free), onchain_check_info (how to buy the on-chain check; does not pay).

Paid on-chain check (x402)

GET https://address-poisoning-check.nextill-pos.workers.dev/v1/check?from=0x...&to=0x...[&chains=ethereum,base,avalanche]

• Answers 402 with an x402 v1 body (X-PAYMENT, network base) and a v2 PAYMENT-REQUIRED header (PAYMENT-SIGNATURE, eip155:8453). Both work.
• 5000 atomic USDC (0.005 USDC) to 0xB3cDDccEe6B150c8efFD55B961afc0Ecefe7f247, settled through the Coinbase CDP facilitator, listed in the CDP x402 Bazaar.
• Settled only after the report is produced; bad input or data-source errors are not charged.
• Data: Ethereum/Avalanche via the Routescan explorer API (last 300 token transfers + 150 transactions of the sender); Base via the Coinbase CDP SQL API (last 14 days of all ERC-20 transfers, including unknown/fake tokens), falling back to public RPC logs for a shorter window. Typical paid response: about 1-2 s. Data collection has a 3.5 s budget; if a source is slow you still get a report with "partial": true and the scanned window stated per chain in chains[].window. It is a heuristic over a window of public data: always confirm the full address with the payee.

Example (the May 2024 $68M WBTC case): from=0x1E227979f0b5BC691a70DEAed2e0F39a6F538FD5&to=0xd9A1C3788D81257612E2581A6ea0aDa244853a91 returns danger / possibly_already_poisoned: the victim did send real value to that address, but it first appeared in their history through a zero-value transfer.

OpenAPI: /openapi.json · Terms: /terms

Related DevX tools

• 7702 Sweeper Check: is an EIP-7702 sweeper delegation set on a wallet?
• Crypto Link Check: is a crypto URL a phishing / drainer lookalike?
• Repo Run Check: is a GitHub repo safe to clone and run?

Layout

• cli/: npm package devx-address-poisoning-check (CLI + stdio MCP), npm test
• worker/: the Cloudflare Worker behind the hosted API (npm run build)

MIT. Made by DevX · [email protected]