ExtrinsicSuccess

Event Re-added v101 → v277, v290 → current #0

Emitted when an extrinsic completes successfully.

Useful for: developerswalletsanalyticsexchanges

The Big Picture

Every transaction (extrinsic) on the chain ends with either ExtrinsicSuccess or ExtrinsicFailed. This is your confirmation that everything worked - state was updated, operation completed, and your transaction is finalized. It's the 'receipt' for any blockchain operation.

Why This Matters

When you submit a transaction, you need to know it worked. ExtrinsicSuccess is the definitive confirmation. Without it, you can't be sure your stake was added, your weights were set, or your transfer completed.

Example Scenario

You call add_stake to stake 100 TAO. The transaction is included in a block. You see StakeAdded (with your stake details) followed by ExtrinsicSuccess (confirming the overall transaction succeeded). Now you know for certain your stake is active.

Common Questions

What if I see the domain event but not ExtrinsicSuccess?: Always wait for ExtrinsicSuccess. In rare cases, events can be emitted but the transaction still fails. ExtrinsicSuccess is the definitive confirmation.
Does ExtrinsicSuccess mean my transaction was free?: No, fees are always charged (shown in fee field). Success just means the operation completed - you still paid for the computation.

Use Cases

Confirm your transaction completed successfully
Build transaction monitoring systems
Track network transaction success rates
Trigger downstream actions on transaction success

How to Use This Event

→ Listen for this after submitting any transaction
→ Pair with specific domain events (e.g., StakeAdded + ExtrinsicSuccess)
→ Monitor network-wide success rates

From Chain Metadata

An extrinsic completed successfully.

Triggers

Preconditions

Extrinsic dispatched without errors
All state changes applied successfully

Effects

Postconditions

All state changes from extrinsic are committed

Side Effects

Other events from the extrinsic are also emitted
Transaction fees deducted from sender

Event Data

#	Name	Type	Description
0	dispatch_info	DispatchEventInfo	Information about the extrinsic dispatch (weight, class, pays_fee)

Code Examples

import { ApiPromise, WsProvider } from "@polkadot/api";
import { stringCamelCase } from "@polkadot/util";

const provider = new WsProvider("wss://entrypoint-finney.opentensor.ai:443");
const api = await ApiPromise.create({ provider });

// Subscribe to ExtrinsicSuccess events
api.query.system.events((events) => {
  events
    .filter(({ event }) =>
      event.section === stringCamelCase("System") &&
      event.method === "ExtrinsicSuccess"
    )
    .forEach(({ event }) => {
      console.log("ExtrinsicSuccess:", event.data.toHuman());
    });
});

On-Chain Activity

Emission Frequency

●●●●●● Infrastructure >50M emissions

Protocol plumbing — fires on nearly every extrinsic

#3 most emitted event

As of block 7,429,232

Version History

Version:

v101 block 1 1 args

v290 block 5,947,548 1 args Current

Runtime Info

Pallet Index: 0
Event Index: 0
First Version: v101
Current Version: v393

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