DelegateCalled

Event v334 → current #7

Emitted when a contract executes code from another contract in its own context.

View events on chain

Useful for: developersanalytics

The Big Picture

Delegate calls run another contract's code in the caller's context - enabling library and proxy patterns.

Use Cases

Track library usage
Monitor proxy behavior
Debug delegate call chains

From Chain Metadata

A contract delegate called a code hash.

Triggers

Emitted by

call call_old_weight

Preconditions

Calling contract exists
Target code exists

Effects

Storage Modified

ContractInfoOf

Postconditions

Code executed in caller's context

Side Effects

State changes apply to calling contract

Event Data

#	Name	Type	Description
0	contract	AccountId	Contract executing the delegate call (hex -> SS58)
1	code_hash	H256	Code being executed via delegation

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 DelegateCalled events
api.query.system.events((events) => {
  events
    .filter(({ event }) =>
      event.section === stringCamelCase("Contracts") &&
      event.method === "DelegateCalled"
    )
    .forEach(({ event }) => {
      console.log("DelegateCalled:", event.data.toHuman());
    });
});

Runtime Info

Pallet Index: 29
Event Index: 7
First Version: v334
Current Version: v393

Back to Contracts Events