App Ids are core to the dev experience on Avail DA, and we highly recommend you understand how they work before you start working with them. You can check out our docs for the same.

Fetch App IDs from Avail DA

On-chain name of method: dataAvailablity_appKeys

Parameters

parameter	type	optional	description
key	string	true	The `app_id` associated with this key will be fetched

Return value

On failure, a reason for failure is returned. On sucess, the returned JSON object contains:

Owner: The owner of the app_id
appID: The numerical index of the app_id

Minimal example (Fetch a particular `app_id`)

You will need to set up the dev enviornment required to run this example. For instructions, check out our docs here.
If you're sending an extrinsic (i.e conducting a transaction) you will need to replace the demo seed phrase with your own seed phrase. The rest of the code should work as is.

Inside your-file-name.ts, add the following code:

avail-js

import { SDK } from "avail-js-sdk"
 
const main = async () => {
  const providerEndpoint = "wss://turing-rpc.avail.so/ws"
  const sdk = await SDK.New(providerEndpoint)
 
  const key = "Reserved-2"
  const value = await sdk.api.query.dataAvailability.appKeys(key)
  console.log(value.toHuman())
 
  process.exit()
}
 
main()

Run the code using:

ts-node your-file-name.ts

Another example (Fetch all available `app_ids` registered on Avail DA)

Think of the dataAvailablity_appKeys as a method that returns all the app_ids registered on Avail DA as a mapping of their names to their owner and index.
In most cases a dev will be interested in fetching only a particular app_id and not all of them.
We are however including both scenarios here.

Inside your-file-name.ts, add the following code: