Check a crypto address before sending

Before any transaction to an address you did not deploy, run the pre-transaction check and read the verdict. It takes under a second and costs a fraction of a cent.

When to use

• A user asks to send, approve, swap, mint or sign for an address or token.
• You are about to call a contract method on behalf of someone.
• Someone pastes an address and asks whether it is safe.

Access

• MCP (preferred): add the hosted server https://tanod.dev/mcp/security (Streamable HTTP). In Claude Code: claude mcp add --transport http tanod https://tanod.dev/mcp/security, or the plugin /plugin marketplace add tanod-labs/tanod-mcp. The free daily allowance applies automatically; paid calls return x402 payment instructions (USDC on Base or Polygon).
• HTTP: POST https://tanod.dev/v1/check/address with a JSON body. Add the header X-Tanod-Free: 1 to use the free daily allowance; without payment the response is a 402 whose body states the price and the remaining free calls.
• No API key, no account. Price: USD 0.005 per check, with a free daily allowance per IP.

How

MCP tool: check_contract_before_interaction with address and chain (base or ethereum).

HTTP:

POST /v1/check/address HTTP/1.1
Host: tanod.dev
content-type: application/json
X-Tanod-Free: 1

{"address":"0x...","chain":"base"}

Reading the result

• verdict or risk with reasons: proxy with an upgradable implementation, unverified source, honeypot-like transfer restrictions, mint or pause functions owned by one key, OFAC match, phishing-list match, very new contract.
• Treat high as stop: tell the user what was found and do not send. Treat medium as ask the user. low is not a guarantee; it means nothing known was found.
• If the check itself fails (timeout, unknown chain), say so and do not proceed silently.

Guardrails

• Never skip the check because the address "looks fine" or was pasted by the user.
• Approve only the amount needed, never unlimited allowances, regardless of the verdict.
• The check is automated and heuristic; it does not replace an audit for large amounts.