Stellar Asset Meta

This is the code behind simple but useful API endpoint https://stellar-asset-meta.apay.workers.dev

It provides a way to load metadata about multiple Stellar assets using just one HTTP request.

Problem

For example, this is useful when you have a list of assets or user balances and you want to display icons for those assets.

Normally you would

• query Horizon server for each issuer account to obtain issuer's home domain
• query stellar.toml file for each home domain and parse it
• extract asset information from the toml file

Imagine user has

• BTC issued by GAUTUYY2THLF7SGITDFMXJVYH3LHDSMGEAKSBU267M2K7A3W543CKUEF
• ETH issued by GBVOL67TMUQBGL4TZYNMY3ZQ5WGQYFPFD5VJRWXR72VA33VFNL225PL5
• LTC issued by GCNSGHUCG5VMGLT5RIYYZSO7VQULQKAJ62QA33DBC5PPBSO57LFWVV6P

Your frontend must send a total of 6 HTTP requests and have toml parser library ready to extract the data.

Solution

GET https://stellar-asset-meta.apay.workers.dev?assets=BTC:GAUTUYY2THLF7SGITDFMXJVYH3LHDSMGEAKSBU267M2K7A3W543CKUEF&assets=ETH:GBVOL67TMUQBGL4TZYNMY3ZQ5WGQYFPFD5VJRWXR72VA33VFNL225PL5&assets=LTC:GCNSGHUCG5VMGLT5RIYYZSO7VQULQKAJ62QA33DBC5PPBSO57LFWVV6P

or

POST https://stellar-asset-meta.apay.workers.dev
[
	{
		"asset_code": "BTC",
		"asset_issuer": "GAUTUYY2THLF7SGITDFMXJVYH3LHDSMGEAKSBU267M2K7A3W543CKUEF"
	},
	{
		"asset_code": "ETH",
		"asset_issuer": "GBVOL67TMUQBGL4TZYNMY3ZQ5WGQYFPFD5VJRWXR72VA33VFNL225PL5"
	},
	{
		"asset_code": "LTC",
		"asset_issuer": "GCNSGHUCG5VMGLT5RIYYZSO7VQULQKAJ62QA33DBC5PPBSO57LFWVV6P"
	}
]

Parameters of POST request are fully compatible with horizon response when loading an account, so you can directly do

const accountData = await horizon.loadAccount(userAccount);
const metaResponse = await fetch('https://stellar-asset-meta.apay.workers.dev', {
    method: 'POST',
    headers: {
      'Accept': 'application/json',
      'Content-Type': 'application/json'
    },
    body: JSON.strongify(accountData.balances),
});
const meta = await metaResponse.json();

Successful response looks like that

{
    "BTC:GAUTUYY2THLF7SGITDFMXJVYH3LHDSMGEAKSBU267M2K7A3W543CKUEF": {
        "status": "live",
        "name": "Bitcoin",
        "image": "https://apay.io/public/logo/btc.svg",
        "transferServer": "https://api.apay.io/api"
    },
    "ETH:GBVOL67TMUQBGL4TZYNMY3ZQ5WGQYFPFD5VJRWXR72VA33VFNL225PL5": {
        "status": "live",
        "name": "Ethereum",
        "image": "https://stellarport.io/assets/issues/eth.png",
        "transferServer": "https://a3s.api.stellarport.io/v3/GBVOL67TMUQBGL4TZYNMY3ZQ5WGQYFPFD5VJRWXR72VA33VFNL225PL5"
    },
    "LTC:GCNSGHUCG5VMGLT5RIYYZSO7VQULQKAJ62QA33DBC5PPBSO57LFWVV6P": {
        "status": "live",
        "name": "Litecoin",
        "image": "https://interstellar.exchange/app/assets/images/coins/LTC.png",
        "transferServer": "https://cryptoanchor.io/stellar/"
    }
}

Running your own

If you don't want to use existing endpoint and want to launch your own instead

• Follow cloudflare instructions to install and configure wrangler cli tool
• cp wrangler.toml.example wrangler.toml and paste values from your own cloudflare account for account_id and zone_id parameters
• wrangler publish

That's it, you're done

However it's beneficial to use the same endpoint as others, because it caches responses and able to serve metadata faster when more people using it