Once a bid is placed, it will remain in the state of the auction contract, even if the bid fails to win a slot immediately. New slots may become available if bonded validators leave the network or reduce their bond amounts. Therefore, a bid must be explicitly withdrawn to remove it from the auction.
This method withdraws a bid using the system auction contract. Call the existing withdraw_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 withdraw_bid \
--session-arg="public_key:public_key='<PUBLIC_KEY_HEX>'" \
--session-arg="amount:u512='<AMOUNT_TO_WITHDRAW>'"
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 withdraw_bid entry point expects two arguments, while the third one is optional:
public key: The hexadecimal public key of the account's purse to withdraw. This key must match the secret key that signs the deploy and has to match the public key of a bid in the auction contract
amount: The amount being withdrawn
The command will return a deploy hash, which is needed to verify the deploy's processing results.
note
Calling the withdraw_bid entry point on the auction contract has a fixed cost of 2.5 CSPR.
Example:
This example command uses the Casper Testnet to withdraw 5 CSPR from the bid:
sudo -u casper casper-client put-deploy \
--node-address http://65.21.75.254:7777 \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--chain-name casper-test \
--payment-amount 2500000000 \
--session-hash hash-93d923e336b20a4c4ca14d592b60e5bd3fe330775618290104f9beb326db7ae2 \
--session-entry-point withdraw_bid \
--session-arg "public_key:public_key='01c297d2931fec7e22b2fb1ae3ca5afdfacc2c82ba501e8ed158eecef82b4dcdee'" \
--session-arg "amount:U512='$[5 * 1000000000]'"
Below is the same command with the optional purse set to a different purse where the amount will be returned. Adjust all the values to your use case.
sudo -u casper casper-client put-deploy \
--node-address http://65.21.75.254:7777 \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--chain-name casper-test \
--payment-amount 2500000000 \
--session-hash hash-93d923e336b20a4c4ca14d592b60e5bd3fe330775618290104f9beb326db7ae2 \
--session-entry-point withdraw_bid \
--session-arg "public_key:public_key='01c297d2931fec7e22b2fb1ae3ca5afdfacc2c82ba501e8ed158eecef82b4dcdee'" \
--session-arg "amount:U512='$[5 * 1000000000]'"
There is a second way to withdraw a bid, using the compiled Wasm withdraw_bid.wasm. The process is the same as bonding but uses a different contract.
sudo -u casper casper-client put-deploy \
--node-address <HOST:PORT> \
--secret-key <PATH> \
--chain-name <CHAIN_NAME> \
--payment-amount <PAYMENT_AMOUNT> \
--session-path <PATH>/casper-node/target/wasm32-unknown-unknown/release/withdraw_bid.wasm \
--session-arg="public_key:public_key='<PUBLIC_KEY_HEX>'" \
--session-arg="amount:u512='<AMOUNT_TO_WITHDRAW>'"
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 estimated
session-path - The path to the compiled Wasm on your computer
The withdraw_bid.wasm expects two arguments, while the third one is optional:
public key: The hexadecimal public key of the account's purse to withdraw. This key must match the secret key that signs the deploy and has to match the public key of a bid in the auction contract
amount: The amount being withdrawn
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 withdraw_bid entrypoint in the system auction contract, which has a fixed cost of 2.5 CSPR.
Example:
Here is an example request to unbond stake using the withdraw_bid.wasm. The payment amount specified is 4 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://65.21.75.254:7777 \
--secret-key /etc/casper/validator_keys/secret_key.pem \
--chain-name casper-test \
--session-path $HOME/casper-node/target/wasm32-unknown-unknown/release/withdraw_bid.wasm \
--payment-amount 4000000000 \
--session-arg="public_key:public_key='01c297d2931fec7e22b2fb1ae3ca5afdfacc2c82ba501e8ed158eecef82b4dcdee'" \
--session-arg="amount:u512='1000000000000'"
Check the auction contract for updates to the bid amounts.
casper-client get-auction-info --node-address http://<HOST:PORT>
To prevent long-range attacks, requests to unbond must go through a mandatory wait period, currently set to 7 eras lasting approximately 14-16 hours.