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OneSource Ethereum RPC – Get Address Nonce
x402
OneSource Ethereum RPC – Get Address Nonce is a paid API for AI agents from api.onesource.io, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-08).
Returns the transaction count (nonce) for an Ethereum address at a specified block on mainnet or Sepolia testnet
Price / call$0.003
Success—
StatusUnknown
How this service works
Two data families for AI agents: live Ethereum mainnet, Sepolia testnet, and Robinhood Chain RPC reads, plus Deepstate on-chain market data (order books, trades, candles, and analytics). Pay per call or use batch/session mode: USDC on Base via x402, or pathUSD/USDC.e on Tempo via MPP. No API key required to start; a flat-rate monthly subscription is also available.
Output
A JSON object containing the address, the requested block tag or number, and the nonce as a hex-encoded integer (e.g. '0x4d2'), representing the total number of transactions sent from that address up to the specified block.
Example use cases
Detect replay attacks across chains
“Check the nonce for my wallet address 0x742d35Cc6634C0532925a3b844Bc9e7595f42456 on Ethereum mainnet and Sepolia — I need to verify if someone could reuse my transaction signature on the testnet.”
Audit transaction history for compliance
“Get the total transaction count for the contract deployer address 0x1234567890abcdef1234567890abcdef12345678 at block 18,000,000 on mainnet — our audit team needs to document all submitted transactions up to that point.”
Validate pending transactions before signing
“What's the nonce at the latest block for my address 0x9876543210fedcba9876543210fedcba98765432? I want to make sure I'm not submitting duplicate transactions while waiting for confirmations.”
Technical details
Endpoint
GEThttps://api.onesource.io/api/chain/nonce/%7Baddress%7DWhen to prefer
Use this endpoint when an AI agent needs to construct, sign, or validate an Ethereum transaction and must know the correct nonce for a sender address. Also useful for auditing how many transactions an address has sent, detecting replay attack risks, or checking pending vs confirmed transaction counts. Prefer over generic JSON-RPC providers when no API key is available and micropayment-per-call billing via x402/USDC is acceptable.
Side effects
- Invalid address format (not 0x-prefixed 40-char hex) returns an error
- Invalid block reference returns an error
- Address with no transactions returns nonce 0x0
- Network parameter typo returns a validation error
- Payment failure or insufficient USDC balance blocks the request
- Node unavailability or rate limits may cause transient 5xx errors
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"data": {
"nonce": "0x4d2"
},
"meta": {
"endpoint": "/api/chain/nonce/{address}",
"cost_usdc": "0.001",
"request_id": "00000000abcdef01",
"payment_chain": "base",
"payment_token": "USDC"
}
}
}Tags
x402
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