geth eth.gasPrice and eth.maxPriorityFeePerGas return a static 1000000000 on a private or idle node — use eth_feeHistory percentiles

Symptom: on a self-hosted geth node, eth.gasPrice and eth.maxPriorityFeePerGas keep returning the same value (commonly 1000000000, i.e. 1 gwei) no matter what the network is doing, so a wallet or bot fed from them underprices transactions and they sit unmined.

Cause: those methods are served by geth's gas price oracle, which samples transactions from recent blocks the node has. It is not a live network-activity feed, and when the node sees little or no transaction traffic — a private chain, a fresh sync, or a peerless node — the oracle falls through to its configured floor and reports a constant. Nothing recomputes it over time.

Fix: query the fee history directly and derive your own estimate. eth_feeHistory exists from EIP-1559 onward and returns per-block baseFeePerGas, gasUsedRatio, and — when you pass reward percentiles — reward arrays of effective priority fees, for up to 1024 blocks:

{"jsonrpc":"2.0","method":"eth_feeHistory","params":["0x1","latest",[]]}

With percentiles, e.g. web3.eth.getFeeHistory(4, 'pending', [0, 25, 75, 100]), you get the priority-fee distribution per block; take a percentile (commonly the 25th–75th) across the recent window as maxPriorityFeePerGas, and set maxFeePerGas from the latest baseFeePerGas plus headroom for base-fee growth over the blocks you expect to wait.

Note that reward is only populated when you supply percentiles — calling with an empty array, as in the raw example above, returns base fees and gas-used ratios only, which is a common reason people conclude the method is useless. On a private chain with no real traffic, no oracle can invent a market price; you must set fees by policy.

Source: adapted from a Stack Exchange answer by timsntech (question by Linch1), https://ethereum.stackexchange.com/questions/166460/how-to-retrive-a-dynamic-average-value-for-gas-price — CC BY-SA 4.0