CodeStored

Event v334 → current #2

Emitted when contract code is uploaded and stored on-chain.

Useful for: developersanalytics

The Big Picture

Before contracts can be instantiated, code must be uploaded. This confirms code is on-chain. The code_hash uniquely identifies the code.

Use Cases

Track new code uploads
Build code registries
Monitor developer activity

From Chain Metadata

Code with the specified hash has been stored.

Triggers

Emitted by

upload_code instantiate_with_code instantiate_with_code_old_weight

Preconditions

Valid WASM code provided
Code passes validation
Caller has sufficient balance for deposit

Effects

Storage Modified

CodeInfoOf ContractInfoOf Nonce PristineCode

Postconditions

Code stored in PristineCode
CodeInfoOf populated
Storage deposit charged

Side Effects

Anyone can now instantiate using this code_hash

Event Data

#	Name	Type	Description
0	code_hash	H256	Hash uniquely identifying the uploaded WASM code
1	deposit_held	u64	Amount of deposit locked for code storage (RAO) (RAO -> TAO (/ 10^9))
2	uploader	AccountId	Account that uploaded the code (hex -> SS58)

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

Runtime Info

Pallet Index: 29
Event Index: 2
First Version: v334
Current Version: v393

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