DustLost
Event v101 → v424, v432 → current #1Emitted when an account's remaining balance is below existential deposit.
View events on chainFrom Chain Metadata
An account was removed whose balance was non-zero but below ExistentialDeposit, resulting in an outright loss.
Migration Notes
v424 v432 Breaking
amount changed from u64 to TaoBalance
Update decoders: SCALE encoding is positional, so any signature change (added, removed, or type-changed fields, or storage shape changes) shifts byte offsets and existing decoders will misparse this item. Re-derive types from the new metadata.
Triggers
Preconditions
- Account balance fell below existential deposit
- Balance was non-zero
Effects
Postconditions
- Remaining balance removed from account
- Dust amount lost/burned
Side Effects
- Account may be reaped
Event Data
| # | Name | Type | Description |
|---|---|---|---|
| 0 | account | AccountId | account: Account address (32 bytes, SS58-encoded) (hex -> SS58) |
| 1 | amount | TaoBalance T::Balance | amount: Balance in chain native currency (RAO for TAO; ÷10⁹) |
Code Examples
import { createClient, Binary } from "polkadot-api";
import { getWsProvider } from "polkadot-api/ws";
import { sub } from "@polkadot-api/descriptors"; // generated by: npx papi add sub -w wss://entrypoint-finney.opentensor.ai:443
const client = createClient(getWsProvider("wss://entrypoint-finney.opentensor.ai:443"));
const api = client.getTypedApi(sub);
// Subscribe to DustLost events
client.finalizedBlock$.subscribe(async (block) => {
const events = await api.event.Balances.DustLost.get(block.hash);
for (const evt of events) {
console.log("DustLost:", evt.payload);
}
});On-Chain Activity
Emission Frequency
●●○○○○ Moderate 10K–100K emissions
Occasional use
#43 most emitted event
As of block 7,429,232
Version History
v101 block 1 2 args
v432 block 8,636,190 2 args Current
Runtime Info
- Pallet Index
- 5
- Event Index
- 1
- First Version
- v101
- Current Version
- v472