crypto.tx

Live EVM transaction status and receipt lookup. Give a transaction hash + chain and get back whether it mined successfully, reverted, or is still pending in the mempool, plus block number, confirmations, timestamp, sender and recipient, value transferred (native unit), gas used, effective gas price, total fee paid, any contract created, and event-log count. Chains: base, ethereum, polygon, arbitrum, optimism. Real-time post-training chain state — use it to confirm a payment settled, detect a reverted transaction, or wait for confirmations before acting. Unknown hash returns 404. Sibling of /api/crypto/gas-oracle (fees) and /api/crypto/address-validate (format).

price

$0.0010 USDC per call

method

GET/api/crypto/tx

payment

x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)

auth

None. Sign the payment, retry with PAYMENT-SIGNATURE.

tier

Tier 0 — no paid upstream

Parameters

Name	Type	Description
`chain`required	string	EVM chain to query: base \| ethereum \| polygon \| arbitrum \| optimism. one of: base \| ethereum \| polygon \| arbitrum \| optimism
`hash`required	string	Transaction hash: 0x followed by 64 hex characters. match ^0x[0-9a-fA-F]{64}$

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/crypto/tx?chain=base&hash=example'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/crypto/tx?chain=base&hash=example' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/crypto/tx?chain=base&hash=example'

TypeScript / Node — @2sio/sdktypescript

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.crypto.tx({
  "chain": "base",
  "hash": "example"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

Python — 2siopython

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.crypto.tx(chain="base", hash="example")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

MCP — Claude Desktop / AgentKit / any MCP hostjson

// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "crypto.tx",
    "arguments": {
      "chain": "base",
      "hash": "example"
    }
  }
}

Response

Field	Type	Description
`ok`	boolean	one of: true
`items`	array
`total`	integer	Total matching rows upstream; null when unknown.
`source`	object

Example response datajson

{
  "ok": true,
  "items": [
    {}
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

Discovery

/api/directory — full catalog of every endpoint
/openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
/.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
/.well-known/mcp/server-card.json — MCP SEP-1649 server card
/llms.txt — plain-text manifest for LLM ingestion

2s.io is x402-native. Every call is paid per-request from a USDC-funded EVM wallet on Base — no signup, no API keys, no monthly fees. Source code: github.com/2s-io/sdk.