ContractEmitted

Event v334 → current #3

Emitted when a contract emits a custom event during execution.

Useful for: developersanalytics

The Big Picture

Contracts can emit their own events. This wraps those custom events. The data field contains contract-defined data that must be decoded using the contract's ABI.

Use Cases

Monitor contract-specific events
Build contract-aware indexers
Debug contract execution

From Chain Metadata

A custom event emitted by the contract.

Triggers

Emitted by

call call_old_weight

Preconditions

Contract is executing
Contract calls seal_deposit_event

Effects

Storage Modified

ContractInfoOf

Postconditions

Custom event data recorded

Side Effects

Gas consumed for event emission

Event Data

#	Name	Type	Description
0	contract	AccountId	Contract that emitted this custom event (hex -> SS58)
1	data	Vec<u8> Vec	Contract-defined event data (decode with contract ABI)

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 ContractEmitted events
client.finalizedBlock$.subscribe(async (block) => {
  const events = await api.event.Contracts.ContractEmitted.get(block.hash);
  for (const evt of events) {
    console.log("ContractEmitted:", evt.payload);
  }
});

Runtime Info

Pallet Index: 29
Event Index: 3
First Version: v334
Current Version: v411

Back to Contracts Events