eth_getBlockTransactionCountByNumber

eth_getBlockTransactionCountByNumber reports how many transactions sit inside an Avalanche C-Chain block, identified by its decimal height (passed as hex) or by a tag such as latest. Because the C-Chain runs the Snowman consensus engine with roughly 1–2 second finality, block heights advance quickly, so this call is a cheap way to sample how busy the chain is without pulling the full block body. AVAX is the native gas token that pays for every transaction counted here. Send the request to https://avalanche.therpc.io/YOUR_API_KEY (chain ID 43114, 0xa86a), and the node returns the transaction count for the requested block.

Use cases

• Poll the latest block's transaction count to gauge real-time C-Chain congestion before submitting time-sensitive swaps on Trader Joe or GMX.
• Build a per-block fullness time-series feeding AVAX fee-estimation heuristics, since the C-Chain's sub-2-second cadence makes density a fast-moving signal.
• Walk a range of block heights to flag empty blocks or unusually dense ones during incident analysis or indexer health checks.

Parameters

Response

Example request

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

Try it live in the Avalanche playground.

Errors & troubleshooting

Common pitfalls

• The pending tag counts transactions currently queued for the next C-Chain block; that figure can shift between two back-to-back calls as the mempool drains and refills.
• The result is a hex string (for example "0x2a"), so run parseInt(value, 16) before any numeric comparison or arithmetic.

Supported networks

• Mainnet — Chain ID: 43114
• Fuji

See also

• eth_getBlockTransactionCountByHash
• eth_blockNumber
• eth_getBlockByNumber
• eth_getTransactionByBlockNumberAndIndex

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