Clarity Keywords
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Introduced in: Clarity 1
output: uint
description:
Returns the current block height of the Stacks blockchain in Clarity 1 and 2. Upon activation of epoch 3.0, block-height will return the same value as tenure-height. In Clarity 3, block-height is removed and has been replaced with stacks-block-height.
example:
There is a bug in Clarity 3 when burn-block-height is used within an at-block expression. Normally, keywords executed within an at-block expression will return the data for that specified block. This bug causes burn-block-height to always return the burn block at the current chain tip, even within an at-block expression. This behavior affects any Clarity 3 contracts and will be fixed in a future hard fork.
Introduced in: Clarity 1
output: uint
description:
Returns the current block height of the underlying burn blockchain as a uint
example:
Introduced in: Clarity 2
output: uint
description:
Returns the 32-bit chain ID of the blockchain running this transaction
example:
Introduced in: Clarity 1
output: principal
description:
Returns the caller of the current contract context. If this contract is the first one called by a signed transaction, the caller will be equal to the signing principal. If contract-call? was used to invoke a function from a new contract, contract-caller changes to the calling contract's principal. If as-contract is used to change the tx-sender context, contract-caller also changes to the same contract principal.
example:
Introduced in: Clarity 1
output: bool
description:
Boolean false constant.
example:
Introduced in: Clarity 2
output: bool
description:
Returns a boolean indicating whether or not the code is running on the mainnet
example:
Introduced in: Clarity 1
output: bool
description:
Returns whether or not the code is running in a regression test
example:
Introduced in: Clarity 1
output: (optional ?)
description:
Represents the none option indicating no value for a given optional (analogous to a null value).
example:
Introduced in: Clarity 3
output: uint
description:
Returns the current Stacks block height.
example:
Introduced in: Clarity 1
output: uint
description:
Returns the total number of micro-STX (uSTX) that are liquid in the system as of this block.
example:
Introduced in: Clarity 3
output: uint
description:
Returns the number of tenures that have passed. When the Nakamoto block-processing starts, this will be equal to the chain length.
example:
Introduced in: Clarity 1
output: bool
description:
Boolean true constant.
example:
Introduced in: Clarity 1
output: principal
description:
Returns the original sender of the current transaction, or if as-contract was called to modify the sending context, it returns that contract principal.
example:
Introduced in: Clarity 2
output: optional principal
description:
Returns the sponsor of the current transaction if there is a sponsor, otherwise returns None.
example:
Use caution when leveraging all contract calls, particularly tx-sender and contract-caller as based on the design, you can unintentionally introduce attack surface area. .
Use caution when leveraging all contract calls, particularly tx-sender and contract-caller as based on the design, you can unintentionally introduce attack surface area. .