Description
Creators currently have no on-form visibility into the Stellar network fee they will pay when submitting or releasing an invoice payment, leading to surprises at signing time. This issue embeds a live fee estimator in the /invoice/new form that queries the Stellar fee stats endpoint in real time, shows the base, median, and surge fee in stroops alongside a human-readable XLM equivalent, and updates whenever the operation count changes (i.e., as recipients are added or removed).
Technical Context
Create hooks/useFeeEstimate.ts that polls StellarSdk.Server.feeStats() every 10 seconds and exposes { baseFee, medianFee, p90Fee, loading, error }. Build components/invoice/FeeEstimateBar.tsx that consumes this hook and accepts operationCount: number as a prop to compute total fee (fee multiplied by ops). Display three tiers (economy/standard/priority) as a segmented bar with tooltips explaining each. Wire operationCount from the current recipient list length in app/invoice/new/page.tsx. The selected fee tier should be surfaced to the Freighter signing call as the fee parameter on TransactionBuilder. Polling must stop when the component unmounts.
Acceptance Criteria
Description
Creators currently have no on-form visibility into the Stellar network fee they will pay when submitting or releasing an invoice payment, leading to surprises at signing time. This issue embeds a live fee estimator in the
/invoice/newform that queries the Stellar fee stats endpoint in real time, shows the base, median, and surge fee in stroops alongside a human-readable XLM equivalent, and updates whenever the operation count changes (i.e., as recipients are added or removed).Technical Context
Create
hooks/useFeeEstimate.tsthat pollsStellarSdk.Server.feeStats()every 10 seconds and exposes{ baseFee, medianFee, p90Fee, loading, error }. Buildcomponents/invoice/FeeEstimateBar.tsxthat consumes this hook and acceptsoperationCount: numberas a prop to compute total fee (fee multiplied by ops). Display three tiers (economy/standard/priority) as a segmented bar with tooltips explaining each. WireoperationCountfrom the current recipient list length inapp/invoice/new/page.tsx. The selected fee tier should be surfaced to the Freighter signing call as thefeeparameter onTransactionBuilder. Polling must stop when the component unmounts.Acceptance Criteria
feeStatsresponsefeeStatspercentiles and their XLM equivalents rounded to 7 decimal placesfeeparameter toTransactionBuilderwhen Freighter initiates the signing flowfeeStatsreturns an error or times out, with a fallback to the Stellar minimum base fee (100 stroops)