eth_getTransactionCount

eth_getTransactionCount returns the number of transactions an address has sent on OP Mainnet — that is, its account nonce — measured at the block you specify. The nonce is what you set on the next transaction you sign, so this call is a prerequisite for building and broadcasting any send. OP Mainnet is an OP Stack optimistic rollup (Bedrock) settling to Ethereum L1, with gas paid in ETH and ~2s blocks, which means the pending nonce advances quickly when you fire transactions in sequence. Send the request to https://optimism.therpc.io/YOUR_API_KEY (chain ID 10, 0xa).

Use cases

• Get the next nonce to assign when constructing a new OP Mainnet transaction.
• Detect stuck transactions by comparing the latest nonce against the pending nonce — a gap means something is queued but not yet mined.
• Batch-send several transactions back-to-back by pre-calculating each nonce from the pending count.
• Analyze an account's activity over time by querying its nonce at historical OP Mainnet blocks.

Parameters

Response

Example request

1curl https://optimism.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_getTransactionCount",
7    "params": [
8        "0x0000000000000000000000000000000000000000",
9        "latest"
10      ],
11    "id": 1
12  }'

Try it live in the Optimism playground.

Errors & troubleshooting

Common pitfalls

• Use the pending tag when firing transactions back-to-back on OP Mainnet; latest returns the same nonce for all of them until each is mined, causing collisions.
• A nonce gap — submitting nonce N+1 before N lands — leaves the later transaction stuck in the queue indefinitely until N arrives.
• For a contract account the nonce counts contracts it has created (each CREATE/CREATE2), not ordinary calls, so it grows differently from an EOA nonce.

Supported networks

• Mainnet — Chain ID: 10
• Sepolia — Chain ID: 11155420

See also

• eth_sendRawTransaction
• eth_getTransactionByHash
• eth_getBalance

1curl https://optimism.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionCount","params":["0x0000000000000000000000000000000000000000",""]}'