Version: 2.0.0

Bonding as a Validator

It is recommended that a bonding request be sent once the node has completed the synchronization process. In a Casper network, bonding takes place through the auction contract via the add_bid.wasm contract. The auction runs for a future era, every era. The chainspec.toml specifies the number of slots available, and the auction will take the top N slots and create the validator set for the future era.

In the Testnet, era durations are approximately two hours. The entire process takes approximately 3 eras. Therefore, the time for bid submission to inclusion in the validator set is a minimum of six hours. Bonding requests (bids) are transactions like any other. Because they are generic transactions, they are more resistant to censorship.

Method 1: Bonding with the System Auction Contract

This method submits a bid using the system auction contract. Call the existing add_bid entry point from the system auction contract. Using this method, you do not need to build any contracts, reducing costs and complexity.

sudo -u casper casper-client put-deploy \
--node-address <HOST:PORT> \
--secret-key <PATH> \
--chain-name <CHAIN_NAME> \
--payment-amount <PAYMENT_AMOUNT_IN_MOTES> \
--session-hash <SESSION_HASH> \
--session-entry-point add_bid \
--session-arg "public_key:public_key='<PUBLIC_KEY_HEX>'" \
--session-arg "amount:u512='<BID_AMOUNT>'" \
--session-arg "delegation_rate:u8='<PERCENT_TO_KEEP_FROM_DELEGATORS>'"
--session-arg "minimum_delegation_amount:u64='<MINIMUM_DELEGATION_AMOUNT>'"
--session-arg "maximum_delegation_amount:u64='<MAXIMUM_DELEGATION_AMOUNT>'"

node-address - An IP address of a peer on the network. The default port of nodes' JSON-RPC servers on Mainnet and Testnet is 7777
secret-key - The file name containing the secret key of the account paying for the Deploy
chain-name - The chain-name to the network where you wish to send the Deploy. For Mainnet, use casper. For Testnet, use casper-test
payment-amount - The payment for the Deploy in motes. This entry point call needs 2.5 CSPR for node version 1.5.1
session-hash - Hex-encoded hash of the stored auction contract, which depends on the network you are using. For Casper's Mainnet and Testnet, the hashes are as follows:

Testnet: hash-93d923e336b20a4c4ca14d592b60e5bd3fe330775618290104f9beb326db7ae2
Mainnet: hash-ccb576d6ce6dec84a551e48f0d0b7af89ddba44c7390b690036257a04a3ae9ea

session-entry-point - Name of the entrypoint that will be used when calling the contract

The add_bid entry point expects three arguments:

public key: The hexadecimal public key of the account's purse submitting the bid. This key must match the secret key that signs the bid
amount: The bidding amount
delegation_rate: Percentage of the rewards that the node operator retains for their services
minimum_delegation_amount (optional): Minimum allowed delegation amount in motes
maximum_delegation_amount (optional): Maximum allowed delegation amount in motes

The command will return a deploy hash, which is needed to verify the deploy's processing results.

note

Calling the add_bid entry point on the auction contract has a fixed cost of 2.5 CSPR.

Example:

This example command uses the Casper Testnet to bid 10,000 CSPR for a validating slot:

sudo -u casper casper-client put-deploy \
--node-address http://65.21.75.254:7777 \
--chain-name casper-test \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--payment-amount 2500000000 \
--session-hash hash-93d923e336b20a4c4ca14d592b60e5bd3fe330775618290104f9beb326db7ae2 \
--session-entry-point add_bid \
--session-arg "public_key:public_key='01c297d2931fec7e22b2fb1ae3ca5afdfacc2c82ba501e8ed158eecef82b4dcdee'" \
--session-arg "amount:U512='$[10000 * 1000000000]'" \
--session-arg "delegation_rate:u8='10'"

Next, check the status of the auction to see if you have won a validator slot.

Method 2: Bonding with Compiled Wasm

Another way to send a bonding transaction to the network is via a deploy containing the compiled add_bid.wasm. For details, refer to Building the Required Contracts.

The following deploy is a template for sending a bonding request:

sudo -u casper casper-client put-deploy \
--node-address http://<HOST:PORT> \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--chain-name <CHAIN_NAME> \
--payment-amount <PAYMENT_AMOUNT> \
--session-path $HOME/casper-node/target/wasm32-unknown-unknown/release/add_bid.wasm \
--session-arg "public_key:public_key='<PUBLIC_KEY_HEX>'" \
--session-arg "amount:u512='<BID-AMOUNT>'" \
--session-arg "delegation_rate:u8='<PERCENT_TO_KEEP_FROM_DELEGATORS>'"
--session-arg "minimum_delegation_amount:u64='<MINIMUM_DELEGATION_AMOUNT>'"
--session-arg "maximum_delegation_amount:u64='<MAXIMUM_DELEGATION_AMOUNT>'"

node-address - An IP address of a peer on the network. The default port of nodes' JSON-RPC servers on Mainnet and Testnet is 7777
secret-key - The file name containing the secret key of the account paying for the Deploy
chain-name - The chain-name to the network where you wish to send the Deploy. For Mainnet, use casper. For Testnet, use casper-test
payment-amount - The payment for the Deploy in motes
session-path - The path to the compiled Wasm on your computer

The add_bid.wasm expects three arguments:

public_key: The hexadecimal public key of the account's purse submitting the bid. This key must match the secret key that signs the bid
amount: The bidding amount
delegation_rate: Percentage of the rewards that the node operator retains for their services
minimum_delegation_amount (optional): Minimum allowed delegation amount in motes
maximum_delegation_amount (optional): Maximum allowed delegation amount in motes

The command will return a deploy hash, which is needed to verify the deploy's processing results.

note

This method is more expensive than calling the add_bid entrypoint in the system auction contract, which has a fixed cost of 2.5 CSPR.

Example:

Here is an example request to bond using the add_bid.wasm. The payment amount specified is 3 CSPR. You must modify the payment and other values in the deploy based on the network's chainspec.toml.

sudo -u casper casper-client put-deploy \
--node-address http://65.21.235.219:7777 \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--chain-name casper-test \
--payment-amount 3000000000 \
--session-path ~/casper-node/target/wasm32-unknown-unknown/release/add_bid.wasm \
--session-arg "public_key:public_key='01c297d2931fec7e22b2fb1ae3ca5afdfacc2c82ba501e8ed158eecef82b4dcdee'" \
--session-arg "amount:U512='$[10000 * 1000000000]'" \
--session-arg "delegation_rate:u8='10'"

Next, check the bid status to see if you have won a validator slot.

Checking the Bid Status

Since the bid was submitted using a deploy like any other, perform get-deploy using the casper-client, to see the execution status.

casper-client get-deploy --node-address http://<HOST:PORT> <DEPLOY_HASH>

If the bid wins the auction, the public key and associated bonded amount will appear in the auction contract as part of the validator set for a future era. To determine if the bid was accepted, query the auction contract:

casper-client get-auction-info --node-address http://<HOST:PORT>

Example auction info response

{
"jsonrpc": "2.0",
"result": {
 "bids": [
   {
     "bid": {
       "bonding_purse": "uref-488a0bbc3c3729f5696965da7a3aeee83805392944e36157909da273255fdb85-007",
       "delegation_rate": 0,
       "delegators": [],
       "release_era": null,
       "reward": "93328432442428418861229954179737",
       "staked_amount": "10000000000000000"
     },
     "public_key": "013f774a58f4d40bd9b6cce7e306e53646913860ef2a111d00f0fe7794010c4012"
   },
   {
     "bid": {
       "bonding_purse": "uref-14e128b099b0c3680100520226e6999b322989586cc22db0630db5ec1329f0a7-007",
       "delegation_rate": 10,
       "delegators": [],
       "release_era": null,
       "reward": "0",
       "staked_amount": "9000000000000000"
     },
     "public_key": "01405133e73ef2946fe3a2d76a4c75d305a04ad6b969f3c4a8a0d27235eb260f87"
   },
   {
     "bid": {
       "bonding_purse": "uref-6c0bf8cee1c0749dd9766376910867a84b2e826eaf6c118fcb0224c7d8d229dd-007",
       "delegation_rate": 10,
       "delegators": [],
       "release_era": null,
       "reward": "266185120443441810685787",
       "staked_amount": "100000000"
     },
     "public_key": "01524a5f3567d7b5ea17ca518c9d0320fb4a75a28a5eab58d06c755c388f20a19f"
   },
   {
     "bid": {
       "bonding_purse": "uref-3880b3daf95f962f57e6a4b1589564abf7deef58a1fb0753d1108316bba7b3d7-007",
       "delegation_rate": 10,
       "delegators": [],
       "release_era": null,
       "reward": "0",
       "staked_amount": "9000000000000000"
     },
     "public_key": "01a6901408eda702a653805f50060bfe00d5e962747ee7133df64bd7bab50b4643"
   },
   {
     "bid": {
       "bonding_purse": "uref-5a777c9cd53456b49eecf25dcc13e12ddff4106175a69f8e24a7c9a4c135df0d-007",
       "delegation_rate": 0,
       "delegators": [],
       "release_era": null,
       "reward": "93328432442428418861229954179737",
       "staked_amount": "10000000000000000"
     },
     "public_key": "01d62fc9b894218bfbe8eebcc4a28a1fc4cb3a5c6120bb0027207ba8214439929e"
   }
 ],
 "block_height": 318,
 "era_validators": [
   {
     "era_id": 20,
     "validator_weights": [
       {
         "public_key": "013f774a58f4d40bd9b6cce7e306e53646913860ef2a111d00f0fe7794010c4012",
         "weight": "10000000000000000"
       },
       {
         "public_key": "01405133e73ef2946fe3a2d76a4c75d305a04ad6b969f3c4a8a0d27235eb260f87",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01524a5f3567d7b5ea17ca518c9d0320fb4a75a28a5eab58d06c755c388f20a19f",
         "weight": "100000000"
       },
       {
         "public_key": "01a6901408eda702a653805f50060bfe00d5e962747ee7133df64bd7bab50b4643",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01d62fc9b894218bfbe8eebcc4a28a1fc4cb3a5c6120bb0027207ba8214439929e",
         "weight": "10000000000000000"
       }
     ]
   },
   {
     "era_id": 21,
     "validator_weights": [
       {
         "public_key": "013f774a58f4d40bd9b6cce7e306e53646913860ef2a111d00f0fe7794010c4012",
         "weight": "10000000000000000"
       },
       {
         "public_key": "01405133e73ef2946fe3a2d76a4c75d305a04ad6b969f3c4a8a0d27235eb260f87",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01524a5f3567d7b5ea17ca518c9d0320fb4a75a28a5eab58d06c755c388f20a19f",
         "weight": "100000000"
       },
       {
         "public_key": "01a6901408eda702a653805f50060bfe00d5e962747ee7133df64bd7bab50b4643",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01d62fc9b894218bfbe8eebcc4a28a1fc4cb3a5c6120bb0027207ba8214439929e",
         "weight": "10000000000000000"
       }
     ]
   },
   {
     "era_id": 22,
     "validator_weights": [
       {
         "public_key": "013f774a58f4d40bd9b6cce7e306e53646913860ef2a111d00f0fe7794010c4012",
         "weight": "10000000000000000"
       },
       {
         "public_key": "01405133e73ef2946fe3a2d76a4c75d305a04ad6b969f3c4a8a0d27235eb260f87",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01524a5f3567d7b5ea17ca518c9d0320fb4a75a28a5eab58d06c755c388f20a19f",
         "weight": "100000000"
       },
       {
         "public_key": "01a6901408eda702a653805f50060bfe00d5e962747ee7133df64bd7bab50b4643",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01d62fc9b894218bfbe8eebcc4a28a1fc4cb3a5c6120bb0027207ba8214439929e",
         "weight": "10000000000000000"
       }
     ]
   },
   {
     "era_id": 23,
     "validator_weights": [
       {
         "public_key": "013f774a58f4d40bd9b6cce7e306e53646913860ef2a111d00f0fe7794010c4012",
         "weight": "10000000000000000"
       },
       {
         "public_key": "01405133e73ef2946fe3a2d76a4c75d305a04ad6b969f3c4a8a0d27235eb260f87",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01524a5f3567d7b5ea17ca518c9d0320fb4a75a28a5eab58d06c755c388f20a19f",
         "weight": "100000000"
       },
       {
         "public_key": "01a6901408eda702a653805f50060bfe00d5e962747ee7133df64bd7bab50b4643",
         "weight": "9000000000000000"
       },
       {
         "public_key": "01d62fc9b894218bfbe8eebcc4a28a1fc4cb3a5c6120bb0027207ba8214439929e",
         "weight": "10000000000000000"
       }
     ]
   }
 ],
 "state_root_hash": "c16ba80ea200d786008f8100ea79f9cfeb8d7d5ee8b133eda5a50dcf1c7131e8"
},
"id": -3624528661787095850
}

Note the era_id and the validator_weights in the response above. The current era is the one with the lowest ID in the era_validators array. For a given era_id, a set of validators is defined. If the public key associated with a bid appears in the validator_weights structure for an era, then the account is bonded in that era.

A Losing Bid

If a bid doesn't win a slot in the auction, it is too low. The resolution is to increase the bid amount. It is possible to submit additional bids, to increase the odds of winning a slot. It is also possible to encourage token holders to delegate stake to you for bonding.

Avoiding Ejection

To stay bonded and avoid ejection, each validator must keep their node running and in sync with the rest of the network. To recover from ejection, you will find more details here.

Withdrawing a Bid

Follow the steps in Unbonding to withdraw a bid.

Method 1: Bonding with the System Auction Contract​

Method 2: Bonding with Compiled Wasm​

Checking the Bid Status​

A Losing Bid​

Avoiding Ejection​

Withdrawing a Bid​