Environment Information

Transaction Information

To get the addresses of the signers of a transaction, use the address field of each signing Account that is passed to the transaction's prepare phase.

There is currently no API that allows getting other transaction information. Please let us know if your use-case demands it by request this feature in an issue.

Block Information

To get information about a block, the functions getCurrentBlock and getBlock can be used:

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  view fun getCurrentBlock(): Block

  
  

  Returns the current block, i.e. the block which contains the currently executed transaction.

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  view fun getBlock(at: UInt64): Block?

  
  

  Returns the block at the given height. If the block exists within the accessible range defined by flow.DefaultTransactionExpiry - 10 (590 blocks), it is returned successfully. If the block at the given height does not exist or is outside the default transaction expiration range of 590 blocks below the current sealed block, the function returns nil.

The Block type contains the identifier, height, and timestamp:

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struct Block {

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/// The ID of the block.

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///

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/// It is essentially the hash of the block.

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///

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let id: [UInt8; 32]

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/// The height of the block.

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///

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/// If the blockchain is viewed as a tree with the genesis block at the root,

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// the height of a node is the number of edges between the node and the genesis block

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///

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let height: UInt64

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/// The view of the block.

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///

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/// It is a detail of the consensus algorithm. It is a monotonically increasing integer

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/// and counts rounds in the consensus algorithm. It is reset to zero at each spork.

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///

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let view: UInt64

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/// The timestamp of the block.

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///

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/// Unix timestamp of when the proposer claims it constructed the block.

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///

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/// NOTE: It is included by the proposer, there are no guarantees on how much the time stamp can deviate from the true time the block was published.

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/// Consider observing blocks’ status changes off-chain yourself to get a more reliable value.

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///

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let timestamp: UFix64

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}