Halffin

Halffin is a peer-to-peer real-world assets marketplace where strangers can trade without middlemen using chainlink oracle to track delivery status ensuring buyers will be charged only if the product is received. This project is part of Chainlink Hackathon Fall 2021.

Prerequisites

Please install or have installed the following:

• nodejs and npm
• python
• aws
• moralis

Installation

1. Set up repo

git clone https://github.com/palsp/halffin-adapter.git
git clone https://github.com/palsp/halffin-frontend.git

2. Install Brownie, if you haven't already. Here is a simple way to install brownie.

python3 -m pip install --user pipx
python3 -m pipx ensurepath
# restart your terminal
pipx install eth-brownie

Or, if that doesn't work, via pip

pip install eth-brownie

3. Set up Chainlink node

4. Set up external adapters

• install dependencies

npm --prefix halffin-adapter install
or
yarn --cwd halffin-adapter install

• start server

yarn emulator:start

NOTE: We use AWS DynamoDB in this step, please set up aws cli and sufficient iam permission to create DynamoDB Table

5. Setup env

Set your WEB3_INFURA_PROJECT_ID, PRIVATE_KEY, and CHAINLINK_NODE_ADDRESS environment variable

• You can get a WEB3_INFURA_PROJECT_ID by getting a free trial of Infura
• You can find your PRIVATE_KEY from your ethereum wallet like metamask.
• You can get a CHAINLINK_NODE_ADDRESS from gui of chainlik node.
  • Go to Keys > Account Address > Address

6. deploy oracle

brownie run scripts/oracle_node/deploy_oracle --network kovan

7. Setup bridge and create job

• Copy url of the adapter and paste it the chainlink node gui.

You can use localhost:3000 for local development

• Create a job in chainlink node gui using the following job's description. Replace ORACLE_ADDRESS with the oracle's address deployed in the previous step and BRIDGE_NAME with the bridge name.

type = "directrequest"
schemaVersion = 1
name = "get-tracking-detail"
contractAddress = <ORACLE_ADDRESS>
maxTaskDuration = "0s"
observationSource = """
       decode_log   [type="ethabidecodelog"
                     abi="OracleRequest(bytes32 indexed specId, address requester, bytes32 requestId, uint256 payment, address callbackAddr, bytes4 callbackFunctionId, uint256 cancelExpiration, uint256 dataVersion, bytes data)"
                     data="$(jobRun.logData)"
                     topics="$(jobRun.logTopics)"]

       decode_cbor  [type="cborparse" data="$(decode_log.data)"]
       fetch        [type=bridge name=<BRIDGE_NAME> requestData="{\\"id\\" : $(jobSpec.externalJobID), \\"data\\" : { \\"trackingId\\" : $(decode_cbor.trackingId)}}"]
       parse        [type="jsonparse" path="data,tracking,tag" data="$(fetch)"]
       encode_data  [type="ethabiencode" abi="(bytes32 value)" data="{ \\"value\\": $(parse) }"]
       encode_tx    [type="ethabiencode"
                     abi="fulfillOracleRequest(bytes32 requestId, uint256 payment, address callbackAddress, bytes4 callbackFunctionId, uint256 expiration, bytes32 data)"
                     data="{\\"requestId\\": $(decode_log.requestId), \\"payment\\": $(decode_log.payment), \\"callbackAddress\\": $(decode_log.callbackAddr), \\"callbackFunctionId\\": $(decode_log.callbackFunctionId), \\"expiration\\": $(decode_log.cancelExpiration), \\"data\\": $(encode_data)}"
                   ]
       submit_tx    [type="ethtx" to=<ORACLE_ADDRESS> data="$(encode_tx)"]

       decode_log -> decode_cbor -> fetch -> parse -> encode_data -> encode_tx -> submit_tx
     """

• Once created you will received external Job ID. Paste the job id in brownie-config.yaml post_job_id field.

8. contract deployment

NOTE: We will keep our adapter and chainlink node up and running on kovan network until the end of December 2021. if you are running on kovan and wish to use our oracle, feel free to skip to instruction 3.

brownie run scripts/escrow-factory/deploy_factory.py --network kovan

9. Setup frontend

yarn --cwd halffin-frontend install

Set your REACT_APP_MORALIS_SERVER_URL, REACT_APP_MORALIS_APP_ID, REACT_APP_TRACKING_SERVER_URL, and REACT_APP_NFTSTORAGE_TOKEN environment variable

• You can get REACT_APP_MORALIS_SERVER_URL and REACT_APP_MORALIS_APP_ID from your moralis dashboard.
• REACT_APP_TRACKING_SERVER_URL is the external adapter from step 3
• You can get REACT_APP_NFTSTORAGE_TOKEN from nft.storage

10. Deploy Moralis cloud function

moralis-admin-cli watch-cloud-folder --moralisApiKey <MORALIS_API_KEY>
--moralisApiSecret <MORALIS_API_SECRET> --moralisSubdomain <MORALIS_SUB_DOMAIN> --autoSave 1 --moralisCloudfolder halffin-frontend/cloud_function

11. Start frontend

yarn --cwd halffin-frontend start

Mock Tracking Number

We provide a mock tracking number so that you do not need to ship anything in order to use our platform. Here the list of tracking number as well as its related delivery status

• Delivered

HF123456789DL

• Fail

HF123456789EX

• In Transit

HF123456789IT

License

This project is licensed under the MIT license.