@evan.network/edge-server-seed

EdgeServer

An ActionHero with built-in blochchain and evan.network infrastructure for developers to implement their own Smart Agents on top of. Also has REDIS built in.

To install:

(assuming you have node and NPM installed)

npm install

To Run:

npm start

To Test:

npm test

SmartAgents

SmartAgents work more or less the same as the SmartAgents in vanilla ActionHero, with two exceptions:

• there is the api.redis object available for local storage

• there is the api.bcc object available that serves as the interface to the blockchain-core

• the agents that perform transactions or need to access encrypted data have to configure the necessary keys in the base level ethAccounts and encryptionKeys config mappings

  ethAccounts: {
      'accountID' : 'privatekey',
  },
  encryptionKeys: {
      'hash':'encryptionkey',
  }
  

The hash to index for encryptionKeys is constructed by the blockchain core in different ways for the different puposes, But usually it is just a SHA3 hash of an accountID or of a descriptive string.

Register SmartAgent

For registering a SmartAgent, create an initializer and add something like in the example below. This creates a new instance of your SmartAgent and makes it available for other actionhero components at the api (in this case at api.smartAgentTest. As this SmartAgent extends api.smartAgents.SmartAgent, it will have a property called runtime, that can be used for interaction with evan.network (see API documentation for details).

const { api, Initializer } = require('actionhero')

module.exports = class SmartAgentTestInitializer extends Initializer {
  constructor () {
    super()
    this.name = 'smart-agent-test'
    this.loadPriority = 4100
    this.startPriority = 4100
    this.stopPriority = 4100
  }

  async initialize () {
    if (api.config.smartAgentTest.disabled) {
      return
    }

    // specialize from blockchain smart agent library
    class SmartAgentTest extends api.smartAgents.SmartAgent {
      async initialize () {
        await super.initialize()
      }
    }

    // start the initialization code
    const smartAgentTest = new SmartAgentTest(api.config.smartAgentTest)
    await smartAgentTest.initialize()

    // objects and values used outside initializer
    api.smartAgentTest = smartAgentTest
  }
}

Auth middleware

By default, the edge-server-seed registers the ensureEvanAuth authentication header that checks a signed message with a provided evan account. So the action can only be executed, when the Authorization header with the correct information was passed (getSmartAgentAuthHeaders). You can use this middleware like below:

const { Action } = require('actionhero')

class Authenticated extends Action {
  constructor () {
    super()
    this.name = 'authenticated'
    this.description = 'Will check if message is signed properly, will throw error if not.'
    this.outputExample = {
      isAuthenticated: true
    }

    this.middleware = ['ensureEvanAuth']
  }

  async run ({ response }) {
    response.isAuthenticated = true
  }
}

module.exports = Authenticated

The latest updates of the @evan.network/api-blockchain-core also provide the possibility to check if the passed EvanAuth address is allowed to interact on behalf of the passed EvanIdentity. To enable this check, you need to register your own authentication middleware from your smart agent instance and pass a valid @evan.network/api-blockchain-core runtime.

• initializer

api.testSmartAgent = new api.smartAgents.SmartAgent({ ... })
await api.testSmartAgent.initialize()
api.testSmartAgent.registerAuthMiddleware('ensureTestAuth', api.testSmartAgent.runtime)

• action

const { Action } = require('actionhero')

class Authenticated extends Action {
  constructor () {
    super()
    this.name = 'authenticated'
    this.description = 'Will check if message is signed properly, will throw error if not.'
    this.outputExample = {
      isAuthenticated: true
    }

    this.middleware = ['ensureTestAuth']
  }

  async run ({ response, evanAuth }) {
    console.log(evanAuth.EvanIdentity)
    response.isAuthenticated = true
  }
}

module.exports = Authenticated