RAAS

Random As A Service (RAAS) powered by chainlink. RAAS provides chainlink verifiable Random Function as a simple REST api. RAAS abstracts the complexity of integrating chainlink services, blockchain technology and decentralized application frontend integration. To use RAAS, there is no need to have a crypto wallet or even crypto itself.

Demo

This project comprises of three parts, the api, the demoapi to receive webhooks and the User Interface for verification. The User Interface is independent, only reads data from the blockchain rather than the api.

To get started, head to:

https://raas.deta.dev

• https://raas.deta.dev
  You will find the api specification and documentation.
  You can create an account with a username, password and dummy email
  You can also use the demo user:
  username: demo
  password: demo

Request RandomWords

To make the post request, you must first be authenticated.

The request takes two parameters:
numWords: int (1-10)
callBackUrl: string
You can use the demo callBackUrl or provide your own.

"https://raasdemo.deta.dev/fulfilment"

The response is a json object on success and error 500 on error:
Sample response:

{"accepted":true,
"requestId":"15260532474928153757688577042866486546840004664658265696233553265432660055854"
}

Webhooks

After the randomWords request has been fulfilled, the results are posted to the callBackUrl provided during the initial request for randomWords.
A signature is provided in the header for verification: x-raas-signature

CONSUMER_SECRET="CGTpgFwSvAXvbLlemYVXLw"

Expected Payload:

{
  "timestamp":"string", // "1667903417"
  "requestId":"string", // "62417537013408832516397952547060344155328317163732249833545943104538413825859"
  "numWords":int, // 1
  "randomWords":str(request[5]) // "[18530413331264412574886300412089947772531121429925866762427491851193136677172]"
}

How to verify: Python

import json
import hmac
computed_sig = hmac.new(CONSUMER_SECRET.encode("utf-8"), msg=json.dumps(data).encode("utf-8"), digestmod=sha512).hexdigest()
if x_raas_signature == computed_sig:
  .
  .
  .

Verification

There are four ways to view the returned random words / number.

1. main api

https://raas.deta.dev/draws

https://raas.deta.dev/draw/{requestId}

https://raas.deta.dev/users/{username}

2. Demo API

https://raasdemo.deta.dev/randomwords

3. Smart Contract
   The smart contract is deployed on the Polygon Mumbai Network.

Address: 0x7E0730E81eEceA3c65fc440a1494de2fF1c8939A

4. raasdemo.info
   The web app provides a simple and clean user interface for verification of the random words generated.

https://raasdemo.info

• https://raasdemo.info

Built With

• chainlink services - VRF v2, Automation and Connect Any API
• Polygon Network - Smart Contract Deployment
• Solidity - The smart contract language
• web3py - For smart contract interaction
• ethers js - For smart contract interaction
• Quasar Framework - For template styling and responsiveness
• FastAPI Framework - For the api
• Deta - For the cloud hosting

Authors

• Robert Mutua - Buidling on web3 - freelancer254

Acknowledgments

• Chainlink