Token Playground Chapter 6 : Wrap a token from Stellar Classic to Soroban.

• Check this guide in https://token-playground.gitbook.io/
• Edit this guide in it's repo: https://github.com/esteblock/token-playground/
• Contribute to this guide in the ./docs folder of the repo

1. Introduction

In the previous chapters we have managed to issue a (classic) Stellar Assets in the (classic) Stellar blockchain.
In this chapter we will wrap that Stellar Asset into a Stellar Asset Contract (SAC) token inside Soroban.

2. Setting up your soroban-cli

Before using the soroban-cli, we need to configure it by telling which account will be executing and signing the transactions. In order to do this, we will call the soroban config identity command and we will provide it with the account's private key.

Here we will suppose that our user is the token admin of the asset, so we will call it token-admin, but you can choose another name for this.

1. Setup your .soroban/identities folder

First create the folder if it does not exist yet

mkdir -p ./soroban/identities

soroban-cli will read from here your identities. Inside this folder you'll need to create one file with .toml for every identity you want to have. If you want to have user-name-1, user-name-2 and user-name-3. Your .soroban/identities folder should have 3 files and should look like this

.soroban/identities/user-name-1.toml
.soroban/identities/user-name-2.toml
.soroban/identities/user-name-3.toml

Where each user-name-X is a text file with the following structure:

secret_key=SBBSXWIML25UV46X3MPC7P4UZISJ2RCCTHHD6PUGRRVHPYLKNXXW2N4I

In this Playground we have our secrets in the ./settings.json file, hence we will do:

TOKEN_ADMIN_SECRET=$(cat ./settings.json | jq -r '.issuerSecret' )
mkdir -p ".soroban/identities"
echo "secret_key = \"$TOKEN_ADMIN_SECRET\"" > ".soroban/identities/token-admin.toml"

1. Configure your soroban-cli to use the token-admin identity

soroban config identity address token-admin

3. Wrap your Stellar Asset into Soroban

For this you'll need the full Stellar Asset identification read our chapter about Basic Concepts. The asset identification is built by:

• The asset code (example: USDC)
• The issuer address (example: GCUA5RTRR4N4ILSMORG3XFXJZB6KRG4QB22Z45BUNO5LIBCOYYPZ6TPZ)

In order to wrap an asset you'll need to use the soroban lab token wrap command as follows:

soroban lab token wrap --network standalone --identity token-admin --asset "ASSET_CODE:ISSUER_ADDRESS"

where the token-admin identity is the identity of the user that will sign the transaction. We will see in a further chapter that this identity does not necessary needs to be the token admin itself.
This command will return the id of the SAC smart contract that will manage the wrapped token.

success
86b9acd9860d105c2b5e6b688ab0fce5f9c45516dcc704f9427936c79384e72f

This correspond to the contract id, a 32-byte byte arrays, represented by BytesN<32>

4. Save the contract ID for further use!

The contract id of this Stellar Asset Contract that is wrapping your Stellar Asset is crucial in order to use the token inside Soroban, so be sure to save it in a safe place!

In order to do this, you can do:

TOKEN_ID=$(soroban lab token wrap $ARGS --asset "$ASSET_CODE:$ISSUER_ADDRESS")
echo "Token wrapped succesfully with TOKEN_ID: $TOKEN_ID"
echo -n "$TOKEN_ID" > .soroban/token_id

What happens if you did not saved the contract id? Don't worry, in Chapter 9 we will show how to recover the contract id of an already wrapped Stellar Asset.

Here, you'll find a fragmet of the code that includes all steps and exemplifies how to wrap a Stellar Asset:

NETWORK="standalone"
ASSET_CODE="MY_ASSET"
TOKEN_ADMIN_ADDRESS="GCUA5RTRR4N4ILSMORG3XFXJZB6KRG4QB22Z45BUNO5LIBCOYYPZ6TPZ"

ARGS="--network $NETWORK --identity token-admin"
TOKEN_ID=$(soroban lab token wrap $ARGS --asset "$ASSET_CODE:$TOKEN_ADMIN_ADDRESS")
echo "Token wrapped succesfully with TOKEN_ID: $TOKEN_ID"

mkdir -p .soroban
echo -n "$TOKEN_ID" > .soroban/token_id

Another example, without the usage of identity can be:

soroban lab token wrap --asset="AstroDollar:GAM5XOXRUWPMKENBGOEAKMLRQ4ENHLHDSU2L2J7TVJ34ZI7S6PHMYIGI" --secret-key SAHC723FQTC3MARBNUZLUFEIYI62VQDQH7FHLD2FGV6GROQQ7ULMHQGH --rpc-url https://horizon-futurenet.stellar.cash:443/soroban/rpc --network-passphrase 'Test SDF Future Network ; October 2022'

5. Use our code

If you want to use our code in the Token Playground's Repo, you can just call our script with the soroban-preview-7 docker containter

You can run it by:

docker exec soroban-preview-7 ./src/wrap.sh standalone using_docker

Check all the code of our wrap.sh script here

Next?

In the next two chapters we will mint tokens inside Soroban from an already wrapped Stellar Asset using its SAC's contract id. Are you ready?

This Playground has been developed by @esteblock in collaboration with @marcos74 from @Dogstarcoin