Karma

The karma module provides a way to limit Transactions. Users are limited in the number and timing of transactions by various karma parameters. There is one user called the Oracle who has unlimited access.

#Installation

To install, include the karma contract in the genesis.json file when starting the chain for the first time:

{
  "vm": "plugin",
  "format": "plugin",
  "name": "karma",
  "location": "karma:1.0.0",
  "init": {
  }
}

#Activation and zeknd.yaml

Activating the karma functionality is done from the zeknd.yaml configuration file.

• KarmaEnabled bool Flag that sets the karma module on or off.

• KarmaSessionDuration int64 A Time period in seconds. Karma restricts users to a configurable number of transactions during any interval of SessionDuration seconds.

• KarmaMaxCallCount int64 Base value used to calculate the number of call Transaction permitted per SessionDuration. A KarmaMaxCallCount int64 of 0 indicates there is no limit imposed.

• KarmaMaxDeployCount int64 Base value used to calculate the number of deploy Transaction permitted per SessionDuration. A KarmaMaxDeployCount int64 of 0 indicates there is no limit imposed.

Example zeknd.yaml fragment:

KarmaEnabled: true
KarmaSessionDuration: 60
KarmaMaxCallCount: 10
KarmaMaxDeployCount: 5

#Accessing karma methods

Public karma methods can either be run either directly in code using one of the SDKs or from the command line the using zeknd executable.

./zeknd karma --help

This will print the following output:

call a method of the karma contract

Usage:
  zeknd karma [command]

Available Commands:
  add-karma      add new source of karma to a user, requires oracle verification
  delete-sources Delete one or more Karma sources for a user
  deposit-coin   deposit coin for deploys to the user's karma
  get-config     list the karma configuration settings
  get-sources    list the karma sources
  get-total      Check amount of karma user has, target can be either CALL or DEPLOY
  get-upkeep     get upkeep parameters
  get-user-state list the karma sources for user
  reset-sources  reset the sources, requires oracle verification
  set-active     set contract as active
  set-config     set the karma configuration settings
  set-inactive   set contract as inactive
  set-upkeep     set upkeep parameters
  update-oracle  change the oracle or set initial oracle
  withdraw-coin  withdraw coin for deploys to the user's karma

Flags:
      --algo string        crypto algo Ed25519 or Secp256k1 (default "ed25519")
      --chain string       chain ID (default "default")
      --contract string    contract address
  -e, --ethereum string    URI for talking to Ethereum (default "http://localhost:8545")
  -h, --help               help for karma
      --hsmconfig string   hsm config file
  -k, --key string         private key file
  -r, --read string        URI for quering app state (default "http://localhost:46658/query")
  -w, --write string       URI for sending txs (default "http://localhost:46658/rpc")

Use "zeknd karma [command] --help" for more information about a command.

#Oracle

• It is defined in the genesis file and can be updated by the UpdateOraclekarma method.

• Note that the oracle is unaffected by karma restrictions.

• To successfully call the following karma configuration transactions it is necessary to reference the oracle:

  • AppendSourcesForUser

  • DeleteSourcesForUser

  • ResetSources

  • UpdateOracle

• If no oracle has been set yet then anyone can call UpdateOracle. If an oracle has been set, it is necessary to know the old oracle in order to update it using UpdateOracle.

Example genesis file entry.

{
 "vm": "plugin",
 "format": "plugin",
 "name": "karma",
 "location": "karma:1.0.0",
 "init": {
   "Oracle": {
     "chainId": "default",
     "local": "QjWhaN9qvpdI9MjS1YuL1GukwLc="
   }
 }
}

#zeknd karma update-oracle

The oracle can be updated using the zeknd update-oracle command, which uses the UpdateOracle karma method:

./zeknd karma update-oracle --help

The output should be similar to this:

change the oracle or set initial oracle

Usage:
  zeknd karma update-oracle <new-oracle> [flags]

Flags:
  -h, --help   help for update-oracle

Global Flags:
      --algo string        crypto algo Ed25519 or Secp256k1 (default "ed25519")
      --chain string       chain ID (default "default")
      --contract string    contract address
  -e, --ethereum string    URI for talking to Ethereum (default "http://localhost:8545")
      --hsmconfig string   hsm config file
  -k, --key string         private key file
  -r, --read string        URI for quering app state (default "http://localhost:46658/query")
  -w, --write string       URI for sending txs (default "http://localhost:46658/rpc")
Andreis-MacBook:zeknd andrei$ ./zeknd karma update-oracle --help
change the oracle or set initial oracle

Usage:
  zeknd karma update-oracle <new-oracle> [flags]

Flags:
  -h, --help   help for update-oracle

Global Flags:
      --algo string        crypto algo Ed25519 or Secp256k1 (default "ed25519")
      --chain string       chain ID (default "default")
      --contract string    contract address
  -e, --ethereum string    URI for talking to Ethereum (default "http://localhost:8545")
      --hsmconfig string   hsm config file
  -k, --key string         private key file
  -r, --read string        URI for quering app state (default "http://localhost:46658/query")
  -w, --write string       URI for sending txs (default "http://localhost:46658/rpc")

As an example, let's say default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 is the current oracle and ./cmd/zeknd/data/priv_key is the path to the oracle's private key . Then, we could update the oracle like this:

./zeknd karma update-oracle karma update-oracle   default:0xAfaA41C81A316111fB0A4644B7a276c26bEA2C9F default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90  -k ./cmd/zeknd/data/priv_key

On success, it will print:

oracle changed

The old oracle can be omitted if no oracle has been set yet.

#Sources

Karma is generated by sources. Sources could correspond to different user types, privilege levels, promotions or temporary changes in status.

type KarmaSourceReward struct {
    Name   string
    Reward int64
}

Nameis a descriptive name (string) used to identify a source. Reward is used to multiply karma associated with the source. A high Reward value means each point of karma generated by the source has more effect than a source with a lower Reward.

Sources can be configured in the genesis.json file or later by calling the karma GetSources and ResetSources methods.

#Sources: Genesis File

Sources can be set up in the karma init segment of the DAppChain genesis file. This allows sources to be available the first time the DAppChain is run. Let's take a look at an example:

{
   "vm": "plugin",
   "format": "plugin",
   "name": "karma",
   "location": "karma:1.0.0",
   "init": {
       "Params": {
           "sources": [
               {
                   "name": "sms",
                   "reward": "1"
               },
               {
                   "name": "oauth",
                   "reward": "3"
               },
               {
                   "name": "token",
                   "reward": "4"
               }
           ]
       }
   }
}

This starts the DAppChain with three sources- "sms", "oauth" and "token". Each source has a different reward level.

#Sources: ResetSources

The karma method ResetSources is used to reset the karma parameters, including the sources, for a running DAppChain.

You might want to download the existing parameters with GetSourcesand amend that before using them to set the karma configuration with UpdateConfig.

#zeknd karma get-sources

To learn more about the available commands, type:

./zeknd karma get-sources --help

You should see something like this:

list the karma sources

Usage:
  zeknd karma get-sources [flags]

Flags:
  -h, --help   help for get-sources

Global Flags:
  -a, --address string   address file
      --chain string     chain ID (default "default")
  -k, --key string       private key file
  -r, --read string      URI for quering app state (default "http://localhost:46658/query")
  -w, --write string     URI for sending txs (default "http://localhost:46658/rpc")

Here's an example:

./zeknd karma get-sources

will print

{
  "sources": [
    {
      "name": "sms",
      "reward": "1"
    },
    {
      "name": "oauth",
      "reward": "3"
    },
    {
      "name": "token",
      "reward": "4"
    }
  ]
}

#zeknd karma reset-sources

The sources can be reset via the zeknd karma update-sources command.

If you want to add to the list of existing sources, you might want to get the list of existing sources first by running zeknd karma get-sources.

Let’s use the built-in help that to discover the available parameters and flags:

./zeknd karma reset-sources --help

You should see something similar to this:

reset the sources

Usage:
  zeknd karma reset-sources (oracle) [ [source] [reward] ]... [flags]

Flags:
  -h, --help   help for update-sources

Global Flags:
  -a, --address string   address file
      --chain string     chain ID (default "default")
  -k, --key string       private key file
  -r, --read string      URI for quering app state (default "http://localhost:46658/query")
  -w, --write string     URI for sending txs (default "http://localhost:46658/rpc")

For example, if default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 has previous been set as the oracle, you could reset sources by running:

./zeknd karma reset-sources default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 "oauth" 3 "token" 5 "test" 7

You should see:

sources successfully updated

#go-zeknd update sources

The following Go code fragment gives an example of how you might do this in Go using go-zeknd.

Note: error checking is skipped for readability.

import `github.com/zekndnetwork/go-zeknd/builtin/types/karma`

func AddSource(name string, reward int64, signer auth.Signer, oracle zeknd.Address, karmaContact client.Contract) {

    // Get the existing configuration parameters
    var resp karma.KarmaSources
    _, err := karmaContact.StaticCall("GetSources", oracle.MarshalPB(), oracle, &resp)

    // Add the new source
    var configVal karma.KarmaSourcesValidator
    configVal.Oracle = oracle.MarshalPB()
    configVal.Sources = append(resp.Sources, &karma.KarmaSourceReward {
            Name: name,
            Reward: reward,
    })

    // Update the source information on the DAppChain
    _, err = karmaContact.Call("ResetSources", &configVal, signer, nil)
}

#Users

If karma has been enabled, each user will be restricted in the transactions they can call by their karma allocation. The following restrictions apply:

#Deploy transactions

Strictly positive karma is required to do any transactions.

If KarmaMaxDeployCount is zero then there is no limit imposed.

Otherwise, users will only be able to deploy a maximum of KarmaMaxDeployCount transactions within a period of SessionDurationseconds.

#Call transactions

Strictly positive karma is required to do any transactions.

If KarmaMaxCallCount is zero then there is no limit imposed.

Otherwise, users will only be able to make KarmaMaxCallCount + total karma call transactions in any period of SessionDuration seconds. The total karma is calculated from the count of sources held by the user as described below.

#User Karma

Each user will be associated with zero or more sources. This list may contain:

• active sources (in karma's current list of sources) or

• inactive sources (not currently in the list of current sources)

type KarmaSource struct {
    Name  string
    Count int64
}

type KarmaAddressSource struct {
    User    *types.Address
    Sources []*KarmaSource
}

Name identifies a source and corresponds to the Name field in the KarmaSourceReward. Count the number of a particular source associated with the address. The amount of karma a source provides to a user is equal to KarmaSource.Count * KarmaSourceReward.Reward.

The total amount of karma is the sum of the karma from each active karma source associated with the user.

The sources associated with a user can be configured either in the genesis file or by the karma methods AppendSourcesForUser and DeleteSourcesForUser.

#Users: Genesis File

Users can be associated with sources in the genesis file. This allows users to have karma available as soon new DAppChain spins up. For example:

{
    "vm": "plugin",
    "format": "plugin",
    "name": "karma",
    "location": "karma:1.0.0",
    "init": {
        "Params": {
            "sources": [
                {
                    "name": "sms",
                    "reward": "1"
                },
                {
                    "name": "oauth",
                    "reward": "3"
                },
                {
                    "name": "token",
                    "reward": "4"
                }
            ],
            "users": [
                {
                    "user": {
                        "chainId": "default",
                        "local": "QjWhaN9qvpdI9MjS1YuL1GukwLc="
                    },
                    "sources": [
                        {
                            "name": "oauth",
                            "count": "10"
                        },
                        {
                            "name": "token",
                            "count": "3"
                        }
                    ]
                }
            ],
        }
    }
}

This genesis file fragment will create three sources and give the user with local address QjWhaN9qvpdI9MjS1YuL1GukwLc:

• 10 rewards from oauth and

• 3 rewards from token.

This user would then start with 10*3 + 3*4 = 42 karma.

#Users: AppendSourcesForUser and DeleteSourcesForUser

In a running DAppChain, we can add a source to a user with the karma method AppendSourcesForUser. In order to do so, we need a list of the names of the new sources, plus a count of the number of rewards. Note that sources can be removed by calling DeleteSourcesForUser.

#zeknd karma append-sources-for-user

New sources can be associated with a user by calling the karma method AppendSourcesForUser. You can also access it via the CLI:

/zeknd karma append-sources-for-user  --help

add new source of karma to a user, requires oracle verification

Usage:
  zeknd karma append-sources-for-user (user) (oracle) [ [source] [count] ]... [flags]

Flags:
  -h, --help   help for append-sources-for-user

Global Flags:
  -a, --address string   address file
      --chain string     chain ID (default "default")
  -k, --key string       private key file
  -r, --read string      URI for quering app state (default "http://localhost:46658/query")
  -w, --write string     URI for sending txs (default "http://localhost:46658/rpc")

For example, if default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 is the oracle and default:0xAfaA41C81A316111fB0A4644B7a276c26bEA2C9F the user to which we want to add a new source, you would want to run something similar to this:

./zeknd karma append-sources-for-user default:0xAfaA41C81A316111fB0A4644B7a276c26bEA2C9F  default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 "oauth" 4 "token" 3 -k ./cmd/zeknd/data/pri

The output of the above command looks like:

sources successfully updated

#zeknd karma delete-sources-for-user

Existing sources can be disassociated with a user using the karma method DeleteSourcesForUser. To do the same, you can use the zeknd karma delete-sources-for-user.

To see the list of available command line parameters and flags, type:

./zeknd karma delete-sources-for-user --help

This command displays the following output:

delete sources assigned to user, requires oracle verification

Usage:
  zeknd karma delete-sources-for-user (user) (oracle) [name]... [flags]

Flags:
  -h, --help   help for delete-sources-for-user

Global Flags:
  -a, --address string   address file
      --chain string     chain ID (default "default")
  -k, --key string       private key file
  -r, --read string      URI for quering app state (default "http://localhost:46658/query")
  -w, --write string     URI for sending txs (default "http://localhost:46658/rpc")

Say default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 is the oracle and default:0xAfaA41C81A316111fB0A4644B7a276c26bEA2C9F the user from which we want to remove sources. We'll delete the sources by running:

./zeknd karma delete-sources-for-user default:0xAfaA41C81A316111fB0A4644B7a276c26bEA2C9F  default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 "oauth" "token" -k ./cmd/zeknd/data/pri

Once the sources are deleted, the above command will print:

sources successfully deleted

#zeknd karma get-user-state

To get the list of sources that have been associated with a user, you can use the zeknd karma get-user-state command.

First, let's take a look at the syntax:

./zeknd karma get-user-state --help

Output:

list the karma sources for user

Usage:
  zeknd karma get-user-state (user address) [flags]

Flags:
  -h, --help   help for get-user-state

Global Flags:
  -a, --address string   address file
      --chain string     chain ID (default "default")
  -k, --key string       private key file
  -r, --read string      URI for quering app state (default "http://localhost:46658/query")
  -w, --write string     URI for sending txs (default "http://localhost:46658/rpc")

For example, if default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90 is the user, you can get the list of the user's sources with the following command:

./zeknd karma get-user-state default:0xDeffe041cC978a193fCf0CE18b43b25B4592FC90

#Karma methods

The following methods can be called by anyone:

• GetSources(ctx contract.StaticContext, ko *types.Address) (*ktypes.KarmaSources, error). Returns the current karma configuration details. This includes the current sources.

• GetTotal(ctx contract.StaticContext, params *types.Address) (*karma.KarmaTotal, error) Returns the total amount of karma in the system. It sums up the karma for each user that has been associated with a source.

• UpdateOracle(ctx contract.Context, params *ktypes.KarmaNewOracleValidator) error. This function can only be called by referencing the oracle unless there is no oracle yet.

The following methods can only be called by referencing the oracle:

• ResetSources(ctx contract.Context, kpo *ktypes.KarmaSourcesValidator) error. Resets the list of possible sources.

• AppendSourcesForUser(ctx contract.Context, ksu *karma.KarmaStateUser) error. Associate a collection of sources with counts for a user. See above for details.

• DeleteSourcesForUser(ctx contract.Context, ksu *karma.KarmaStateKeyUser) error Disassociate a collection of sources for a user. See above for details.

Other methods:

• Meta() (plugin.Meta, error)

• Init(ctx contract.Context, req *InitRequest) error

#Genesis entries

An example genesis file entry is shown below:

{
    "vm": "plugin",
    "format": "plugin",
    "name": "karma",
    "location": "karma:1.0.0",
    "init": {
    "Oracle": {
        "chainId": "default",
        "local": "QjWhaN9qvpdI9MjS1YuL1GukwLc="
     },
    "sources": [
        {
        "name": "sms",
        "reward": "1"
        },
        {
        "name": "oauth",
        "reward": "3"
        },
        {
        "name": "token",
        "reward": "4"
        }
    ],
    "users": [
        {
        "user": {
            "chainId": "default",
            "local": "QjWhaN9qvpdI9MjS1YuL1GukwLc="
        },
        "sources": [
            {
            "name": "oauth",
            "count": "10"
            },
            {
            "name": "token",
            "count": "3"
            }
        ]
        }
    ]

    }
}

A few things to note:

• if the init block is left empty, it will just install the karma contact on the DAppChain.

• You can define an Oracle in the genesis file. As an alternative, you can create an oracle later by calling the karma method UpdateOracle.

• It is possible to initialize the karma contract with a list of karma sources. If you do this, you can also allocate a list of users to have allocated amounts of these sources.