Interacting with the NFT Contract using the Rust Casper Client

This document describes interacting with NFTs on a Casper network using the Rust command-line client.

Prerequisites

• Install the contract using the Quickstart or the Full Installation tutorials
• Learn to Query NFT Contracts and save the various hashes and URefs required throughout this document

Table of Contents

1. Directly Invoking Entrypoints

2. Minting NFTs

3. Transferring NFTs

4. Checking Balances

5. Approving an Account

6. Burning NFTs

7. Next Steps

Directly Invoking Entrypoints

With the release of CEP-78 version 1.1, users interacting with a CEP-78 contract that does not use ReverseLookupMode should opt out of using the client Wasm files provided as part of the release. Opting out in this situation is recommended, as directly invoking the entrypoints incurs a lower gas cost than using the provided client Wasm to invoke the entrypoint.

You may invoke the mint, transfer, or burn entrypoints directly through either the contract package hash or the contract hash directly.

In the case of mint, fewer runtime arguments must be provided, thereby reducing the total gas cost of minting an NFT.

Example `mint` using the stored package hash

casper-client put-deploy --node-address http://localhost:11101/rpc/ \
--chain-name "casper-net-1” \
--payment-amount 5000000000 \
--secret-key ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-package-hash hash-2b61207cd0e94ce1b1d40801b0abb1ab55fd7dae94c9dcf670292243f3791a30 \
--session-entry-point "mint" \
--session-arg "token_owner:key='account-hash-e70dbca48c2d31bc2d754e51860ceaa8a1a49dc627b20320b0ecee1b6d9ce655'" \
--session-arg "token_meta_data:string='{\"name\": \"John Doe\",\"token_uri\": \"https:\/\/www.barfoo.com\",\"checksum\": \"940bffb3f2bba35f84313aa26da09ece3ad47045c6a1292c2bbd2df4ab1a55fb\"}'"

Example `transfer` using the stored contract hash

Based on the identifier mode for the given contract instance, either the token_id runtime argument must be passed in or, in the case of the hash identifier mode, the token_hash runtime argument.

casper-client put-deploy --node-address http://localhost:11101/rpc/ \
--chain-name "casper-net-1” \
--payment-amount 5000000000 \
--secret-key ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-hash hash-378a43e38bc5129d8aa3bcd04f5c9a97be73f85b5be574182ac1346f04520796 \
--session-entry-point "transfer" \
--session-arg "source_key:key='account-hash-e70dbca48c2d31bc2d754e51860ceaa8a1a49dc627b20320b0ecee1b6d9ce655'" \
--session-arg "target_key:key='account-hash-0ea7998b2822afe5b62b08a21d54c941ad791279b089f3f7ede0d72b477eca34'" \
--session-arg "token_id:u64='0'"

Minting NFTs

Below is an example of a casper-client command that uses the mint entrypoint of the contract to mint an NFT for the user associated with node-1 in an NCTL environment.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem --session-entry-point "mint"

1. --session-package-hash hash-2b61207cd0e94ce1b1d40801b0abb1ab55fd7dae94c9dcf670292243f3791a30

   The package hash of the previously installed CEP-78 NFT contract from which we will be minting.

2. --session-arg "token_owner:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'"

   The collection name of the NFT to be minted.

3. --session-arg "token_meta_data:string='{\"name\": \"John Doe\",\"token_uri\": \"https:\/\/www.barfoo.com\",\"checksum\": \"940bffb3f2bba35f84313aa26da09ece3ad47045c6a1292c2bbd2df4ab1a55fb\"}'"

   Metadata describing the NFT to be minted, passed in as a string.

Casper client command without comments

casper-client put-deploy --node-address http://localhost:11101/rpc/ \
--chain-name "casper-net-1” \
--payment-amount 5000000000 \
--secret-key ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-entry-point "mint" \
--session-package-hash hash-2b61207cd0e94ce1b1d40801b0abb1ab55fd7dae94c9dcf670292243f3791a30 \
--session-arg "token_owner:key='account-hash-e70dbca48c2d31bc2d754e51860ceaa8a1a49dc627b20320b0ecee1b6d9ce655'" \
--session-arg "token_meta_data:string='{\"name\": \"John Doe\",\"token_uri\": \"https:\/\/www.barfoo.com\",\"checksum\": \"940bffb3f2bba35f84313aa26da09ece3ad47045c6a1292c2bbd2df4ab1a55fb\"}'"

note

If the identifier_mode was set to hash (1) during installation, the token_hash runtime argument needs to be specified during minting. Since you already know the NFT's identifier, you can easily query the NFT's meta_data, which is a very useful feature. This example uses an ordinal (0) identifier_mode.

Minting NFTs using Wasm

This example invokes the mint_call.wasm session code provided in the client folder.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem --session-path ~/casper/enhanced-nft/client/mint_session/target/wasm32-unknown-unknown/release/mint_call.wasm

1. --session-arg "nft_contract_hash:key='hash-206339c3deb8e6146974125bb271eb510795be6f250c21b1bd4b698956669f95'"

   The contract hash of the previously installed CEP-78 NFT contract from which we will be minting.

2. --session-arg "collection_name:string='cep78_<collection_name>'"

   The collection name of the previously installed CEP-78 NFT contract from which we will be minting.

3. --session-arg "token_owner:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'"

   The collection name of the NFT to be minted.

4. --session-arg "token_meta_data:string='{\"name\": \"John Doe\",\"token_uri\": \"https:\/\/www.barfoo.com\",\"checksum\": \"940bffb3f2bba35f84313aa26da09ece3ad47045c6a1292c2bbd2df4ab1a55fb\"}'"

   Metadata describing the NFT to be minted, passed in as a string.

Casper client command without comments

casper-client put-deploy --node-address http://localhost:11101/rpc/ \
--chain-name "casper-net-1” \
--payment-amount 5000000000 \
--secret-key ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-path ~/casper/enhanced-nft/client/mint_session/target/wasm32-unknown-unknown/release/mint_call.wasm \
--session-arg "nft_contract_hash:key='hash-206339c3deb8e6146974125bb271eb510795be6f250c21b1bd4b698956669f95'" \
--session-arg "collection_name:string='cep78_<collection_name>'" \
--session-arg "token_owner:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'"  \
--session-arg "token_meta_data:string='{\"name\": \"John Doe\",\"token_uri\": \"https:\/\/www.barfoo.com\",\"checksum\": \"940bffb3f2bba35f84313aa26da09ece3ad47045c6a1292c2bbd2df4ab1a55fb\"}'"

Transferring NFTs

Below is an example of a casper-client command that uses the transfer entrypoint to transfer ownership of an NFT from one user to another.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem --session-entry-point "transfer"

1. --session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5'"

   The contract hash of the CEP-78 NFT Contract associated with the NFT to be transferred.

2. --session-arg "source_key:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'"

   The account hash of the user that currently owns the NFT and wishes to transfer it.

3. --session-arg "target_key:key='account-hash-b4772e7c47e4deca5bd90b7adb2d6e884f2d331825d5419d6cbfb59e17642aab'"

   The account hash of the user that will receive the NFT.

4. --session-arg "is_hash_identifier_mode:bool='false'"

   The argument that the hash identifier mode is ordinal, thereby requiring a token_id rather than a token_hash.

5. --session-arg "token_id:u64='0'"

   The token_id of the NFT to be transferred.

Casper client command without comments

casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" \
--payment-amount 5000000000 \
-k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-entry-point "transfer" \
--session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5 \
--session-arg "source_key:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'" \
--session-arg "target_key:key='account-hash-b4772e7c47e4deca5bd90b7adb2d6e884f2d331825d5419d6cbfb59e17642aab'" \
--session-arg "is_hash_identifier_mode:bool='false'" \
--session-arg "token_id:u64='0'"

This command will return a deploy hash that you can query using casper-client get-deploy. Querying the deploy allows you to verify execution success, but you will need to use the balance_of entrypoint to verify the account's balance as shown below.

Transferring NFTs using Wasm

This example uses the transfer_call.wasm session code to transfer ownership of an NFT from one user to another.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/secret_key.pem --session-path ~/casper/enhanced-nft/client/transfer_session/target/wasm32-unknown-unknown/release/transfer_call.wasm

1. --session-arg "nft_contract_hash:key='hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5'"

   The contract hash of the CEP-78 NFT Contract associated with the NFT to be transferred.

2. --session-arg "source_key:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'"

   The account hash of the user that currently owns the NFT and wishes to transfer it.

3. --session-arg "target_key:key='account-hash-b4772e7c47e4deca5bd90b7adb2d6e884f2d331825d5419d6cbfb59e17642aab'"

   The account hash of the user that will receive the NFT.

4. --session-arg "is_hash_identifier_mode:bool='false'"

   Argument that the hash identifier mode is ordinal, thereby requiring a token_id rather than a token_hash.

5. --session-arg "token_id:u64='0'"

   The token_id of the NFT to be transferred.

Casper client command without comments

casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" \
--payment-amount 5000000000 \
-k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-2/keys/secret_key.pem \
--session-path ~/casper/enhanced-nft/client/transfer_session/target/wasm32-unknown-unknown/release/transfer_call.wasm \
--session-arg "nft_contract_hash:key='hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5'" \
--session-arg "source_key:key='account-hash-e9ff87766a1d2bab2565bfd5799054946200b51b20c3ca7e54a9269e00fe7cfb'" \
--session-arg "target_key:key='account-hash-b4772e7c47e4deca5bd90b7adb2d6e884f2d331825d5419d6cbfb59e17642aab'" \
--session-arg "is_hash_identifier_mode:bool='false'" \
--session-arg "token_id:u64='0'"

Checking Balances

To check an account's balance, get the latest state root hash and query the balances dictionary given the NFT contract hash and the owner's account hash without the "account-hash-" prefix, as shown below.

• casper-client get-dictionary-item -n http://localhost:11101/rpc

1. --state-root-hash f22e8ecfb3d2700d5f902c83da456c32f130b73d0d35037fe89b2d4b4933673f

   The latest state root hash.

2. --contract-hash hash-378a43e38bc5129d8aa3bcd04f5c9a97be73f85b5be574182ac1346f04520796

   The NFT contract hash.

3. --dictionary-name "balances"

   The dictionary tracking the number of tokens for each account hash.

4. --dictionary-item-key "0ea7998b2822afe5b62b08a21d54c941ad791279b089f3f7ede0d72b477eca34"

   The account hash of the user whose token balance we are checking without the account-hash- prefix.

Casper client commands without comments

casper-client get-state-root-hash --node-address https://rpc.testnet.casperlabs.io/

casper-client get-dictionary-item -n http://localhost:11101/rpc/ \
--state-root-hash f22e8ecfb3d2700d5f902c83da456c32f130b73d0d35037fe89b2d4b4933673f \
--contract-hash hash-378a43e38bc5129d8aa3bcd04f5c9a97be73f85b5be574182ac1346f04520796 \
--dictionary-name "balances" \
--dictionary-item-key "0ea7998b2822afe5b62b08a21d54c941ad791279b089f3f7ede0d72b477eca34"

Approving an Account

The Casper NFT contract features an approve entrypoint, allowing another account to manage a specific token. During contract installation, the ownership_mode must be set to 2, meaning Transferable.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem --session-entry-point "approve"

1. --session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5

   The contract hash of the previously installed CEP-78 NFT contract.

2. --session-arg "spender:key='account-hash-17192017d32db5dc9f598bf8ac6ac35ee4b64748669b00572d88335941479513'"

   The hash of the account receiving the approval.

3. --session-arg "token_id:u64='1'"

   The token ID of the approved NFT.

Casper client command without comments

casper-client put-deploy -n http://localhost:11101/rpc/ \
--chain-name "casper-net-1" \
--payment-amount 5000000000 \
-k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-entry-point "approve" \
--session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5 \
--session-arg "spender:key='account-hash-17192017d32db5dc9f598bf8ac6ac35ee4b64748669b00572d88335941479513'" \
--session-arg "token_id:u64='1'"

Burning NFTs

Below is an example of a casper-client command that uses the burn entrypoint to burn an NFT within a CEP-78 collection. If this command is used, the NFT in question will no longer be accessible by anyone.

• casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" --payment-amount 5000000000 -k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem

1. --session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5

   The session hash corresponding to the NFT's contract hash.

2. --session-entry-point "burn"

   The entrypoint corresponding to the burn function.

3. --session-arg "token_id:u64='1'"

   The token ID for the NFT to be burned. If the identifier_mode is not set to Ordinal, you must provide the token_hash instead.

Casper client command without comments

casper-client put-deploy -n http://localhost:11101/rpc --chain-name "casper-net-1" \
--payment-amount 5000000000 \
-k ~/casper/casper-node/utils/nctl/assets/net-1/nodes/node-1/keys/secret_key.pem \
--session-hash hash-52e78ae3f6c485d036a74f65ebbb8c75fcc7c33fb42eb667fb32aeba72c63fb5 \
--session-entry-point "burn" \
--session-arg "token_id:u64='1'"

Next Steps

• Testing Framework for CEP-78