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Contract deploy and interact

The AEA erc1155_deploy and erc1155_client skills demonstrate an interaction between two AEAs with the usage of a smart contract.

  • The erc1155_deploy skill deploys the smart contract, creates and mints items.
  • The erc1155_client skill signs a transaction to complete a trustless trade with the counterparty.

Preparation instructions

Dependencies

Follow the Preliminaries and Installation sections from the AEA quick start.

Discussion

The scope of the specific demo is to demonstrate how to deploy a smart contract and interact with it. For the specific use-case, we create two AEAs one that deploys and creates tokens inside the smart contract and the other that signs a transaction so we can complete an atomic swap. The smart contract we are using is an ERC1155 smart contract with a one-step atomic swap functionality. That means the trade between the two AEAs can be trustless.

Note

This demo serves demonstrative purposes only. Since the AEA deploying the contract also has the ability to mint tokens, in reality the transfer of tokens from the AEA signing the transaction is worthless.

Demo

Create the deployer AEA

Fetch the AEA that will deploy the contract.

aea fetch fetchai/erc1155_deployer:0.21.0
cd erc1155_deployer
aea install
aea build
Alternatively, create from scratch.

Create the AEA that will deploy the contract. 

aea create erc1155_deployer
cd erc1155_deployer
aea add connection fetchai/p2p_libp2p:0.14.0
aea add connection fetchai/soef:0.15.0
aea add connection fetchai/ledger:0.12.0
aea add skill fetchai/erc1155_deploy:0.20.0
aea install
aea build
aea config set agent.default_connection fetchai/p2p_libp2p:0.14.0
aea config set --type dict agent.default_routing \
'{
  "fetchai/contract_api:0.10.0": "fetchai/ledger:0.12.0",
  "fetchai/ledger_api:0.9.0": "fetchai/ledger:0.12.0",
  "fetchai/oef_search:0.12.0": "fetchai/soef:0.15.0"
}'
aea config set --type list vendor.fetchai.connections.p2p_libp2p.cert_requests \
'[{"identifier": "acn", "ledger_id": "ethereum", "not_after": "2022-01-01", "not_before": "2021-01-01", "public_key": "fetchai", "save_path": ".certs/conn_cert.txt"}]'
And change the default ledger: 
aea config set agent.default_ledger ethereum

Additionally, create the private key for the deployer AEA. Generate and add a key for Ethereum use: 

aea generate-key ethereum
aea add-key ethereum ethereum_private_key.txt

And one for the P2P connection: 

aea generate-key fetchai fetchai_connection_private_key.txt
aea add-key fetchai fetchai_connection_private_key.txt --connection

Finally, certify the key for use by the connections that request that: 

aea issue-certificates

Create the client AEA

In another terminal, fetch the AEA that will get some tokens from the deployer.

aea fetch fetchai/erc1155_client:0.21.0
cd erc1155_client
aea install
aea build
Alternatively, create from scratch.

Create the AEA that will get some tokens from the deployer. 

aea create erc1155_client
cd erc1155_client
aea add connection fetchai/p2p_libp2p:0.14.0
aea add connection fetchai/soef:0.15.0
aea add connection fetchai/ledger:0.12.0
aea add skill fetchai/erc1155_client:0.19.0
aea install
aea build
aea config set agent.default_connection fetchai/p2p_libp2p:0.14.0
aea config set --type dict agent.default_routing \
'{
  "fetchai/contract_api:0.10.0": "fetchai/ledger:0.12.0",
  "fetchai/ledger_api:0.9.0": "fetchai/ledger:0.12.0",
  "fetchai/oef_search:0.12.0": "fetchai/soef:0.15.0"
}'
aea config set --type list vendor.fetchai.connections.p2p_libp2p.cert_requests \
'[{"identifier": "acn", "ledger_id": "ethereum", "not_after": "2022-01-01", "not_before": "2021-01-01", "public_key": "fetchai", "save_path": ".certs/conn_cert.txt"}]'
And change the default ledger: 
aea config set agent.default_ledger ethereum

Additionally, create the private key for the client AEA. Generate and add a key for Ethereum use: 

aea generate-key ethereum
aea add-key ethereum ethereum_private_key.txt

And one for the P2P connection: 

aea generate-key fetchai fetchai_connection_private_key.txt
aea add-key fetchai fetchai_connection_private_key.txt --connection

Finally, certify the key for use by the connections that request that: 

aea issue-certificates

Run Ganache

Run the following command 

docker run -p 8545:8545 trufflesuite/ganache-cli:latest --verbose --gasPrice=0 --gasLimit=0x1fffffffffffff --account="$(cat erc1155_deployer/ethereum_private_key.txt),1000000000000000000000" --account="$(cat erc1155_client/ethereum_private_key.txt),1000000000000000000000"

To check the wealth use (after some time for the wealth creation to be mined on Ropsten):

aea get-wealth ethereum

You should get 1000000000000000000000.

Note

If no wealth appears after a while, then try funding the private key directly using a web faucet.

Update SOEF configurations for both AEAs

To update the SOEF configuration, run in each AEA project: 

aea config set vendor.fetchai.connections.soef.config.chain_identifier ethereum

Run the AEAs

First, run the deployer AEA.

aea run

Once you see a message of the form To join its network use multiaddr 'SOME_ADDRESS' take note of the address.

It will perform the following steps: - deploy the smart contract - create a batch of items in the smart contract - mint a batch of items in the smart contract

At some point you should see the log output: 

registering service on SOEF.

Then, update the configuration of the client AEA's P2P connection by appending the following YAML text at the end of the aea-config.yaml file:

---
public_id: fetchai/p2p_libp2p:0.14.0
type: connection
config:
  delegate_uri: 127.0.0.1:11001
  entry_peers:
  - SOME_ADDRESS
  local_uri: 127.0.0.1:9001
  log_file: libp2p_node.log
  public_uri: 127.0.0.1:9001

where SOME_ADDRESS is the output of aea get-multiaddress fetchai -c -i fetchai/p2p_libp2p:0.14.0 -u public_uri) in the erc1155_deployer project. The output will be something like /dns4/127.0.0.1/tcp/9000/p2p/16Uiu2HAm2JPsUX1Su59YVDXJQizYkNSe8JCusqRpLeeTbvY76fE5.

Or, run these commands (replace SOME_ADDRESS as above): 

aea config set --type dict vendor.fetchai.connections.p2p_libp2p.config \
'{
  "delegate_uri": "127.0.0.1:11001",
  "entry_peers": ["SOME_ADDRESS"],
  "local_uri": "127.0.0.1:9001",
  "log_file": "libp2p_node.log",
  "public_uri": "127.0.0.1:9001"
}'

Then, in the separate terminal run the client AEA.

aea run

You will see that upon discovery the two AEAs exchange information about the transaction and the client at the end signs and sends the signature to the deployer AEA to send it to the network.

Note

Transactions on Ropsten can take a significant amount of time! If you run the example a second time, and the previous transaction is still pending, it can lead to a failure. The warning message `Cannot verify whether transaction improves utility. Assuming it does!` can be ignored.

Delete the AEAs

When you're done, go up a level and delete the AEAs. 

cd ..
aea delete erc1155_deployer
aea delete erc1155_client

Communication

This diagram shows the communication between the various entities as data is successfully trustless trade.

sequenceDiagram participant Search participant Erc1155_contract participant Client_AEA participant Deployer_AEA participant Blockchain activate Deployer_AEA activate Search activate Client_AEA activate Erc1155_contract activate Blockchain Deployer_AEA->>Blockchain: deployes smart contract Deployer_AEA->>ERC1155_contract: creates tokens Deployer_AEA->>ERC1155_contract: mint tokens Deployer_AEA->>Search: register_service Client_AEA->>Search: search Search-->>Client_AEA: list_of_agents Client_AEA->>Deployer_AEA: call_for_proposal Deployer_AEA->>Client_AEA: inform_message Client_AEA->>Deployer_AEA: signature Deployer_AEA->>Blockchain: send_transaction Client_AEA->>ERC1155_contract: asks_balance deactivate Deployer_AEA deactivate Search deactivate Client_AEA deactivate ERC1155_contract deactivate Blockchain