Avoid dust coin selection in transactions - #548
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Add MINIMUM_UTXO_VALUE_SATS constant (default 546 sats, configurable via environment variable) and use it to filter dust UTXOs out of coin selection both server-side in NodeGuardService and in the Wallets UI. - Introduce MINIMUM_UTXO_VALUE_SATS in Constants with env-var override - Server-side: append dust outpoints to ignoreOutpoints so selection strategies don't count them toward requested amounts (which would otherwise result in short selections after local stripping) - UI: mark dust UTXOs with a warning "dust" badge and disable the freeze toggle for them, since they are auto-excluded
Jossec101
enabled auto-merge (squash)
July 30, 2026 11:50
When `NBXPLORER_ENABLE_CUSTOM_BACKEND` is enabled, locked, frozen and dust UTXOs were counted by the backend towards the requested amount and only stripped by the local filter afterwards, producing selections that fell short of the target. - Extract `GetLockedFrozenOutpoints` from `FilterLockedFrozenUTXOs` so the outpoint list can be reused. - Fetch all UTXOs, compute dust outpoints (<= `MINIMUM_UTXO_VALUE_SATS`) and merge them with locked/frozen outpoints, then forward the combined list to `GetUTXOsByLimitAsync` as `ignoreOutpoints`. - Make `Constants.NBXPLORER_ENABLE_CUSTOM_BACKEND` mutable so tests can toggle the custom-backend path.
RodriFS
reviewed
Jul 30, 2026
Jossec101
disabled auto-merge
July 30, 2026 13:33
…ern of maximum amount of ignored outpoints. When `NBXPLORER_ENABLE_CUSTOM_BACKEND` is enabled and the custom UTXO selection endpoint throws, callers previously got a hard failure. Wrap the custom-backend path in a try/catch and degrade to the plain `GetUTXOsAsync` listing on error, matching the code path used when the custom backend is disabled. The local filter still strips locked, frozen and dust UTXOs, so none can leak through. A warning is logged with the requested strategy for observability. Adds a unit test covering the failure path to ensure the fallback returns only the available UTXO and excludes locked and dust ones.
Restore the previous GetAvailableUtxos behavior where a failing custom NBXplorer backend yields an empty UTXO selection instead of surfacing an error to the caller. NBXplorerService.GetUTXOsByLimitAsync now correctly throws on non-success responses (replacing the unreachable empty return and fixing `throw e` stack rewrite), so NodeGuardService wraps the call in try/catch, logs a warning, and falls back to an empty UTXOChanges. Adds a unit test covering the custom-backend failure path.
markettes
reviewed
Jul 30, 2026
… redundant RPC dust filter Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
markettes
approved these changes
Jul 30, 2026
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Implement logic to prevent the selection of dust coins during transaction creation, this shall prevent dust attacks.
Dust UTXOs are tagged accordinly and cannot be frozen/unfrozen.