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Arkade Transactions

Arkade transactions are the default mode of transacting on Arkade. They are executed offchain in the virtual mempool which is Arkade’s virtual execution layer, a high-throughput environment where transactions flow without the constraints of block times or confirmation delays. Transactions in the virtual mempool form a directed acyclic graph (DAG) that enables parallel execution of offchain transactions. Arkade’s DAG structure explicitly encodes transaction dependencies. When a wallet broadcasts a transaction to the virtual mempool, the operator validates it against the current VTXO set, forwards it to the Arkade Signer who cosigns it if valid, and immediately updates the graph. This gives users instant preconfirmation without waiting for block inclusion. The transaction’s outputs become immediately spendable, enabling real-time execution of financial applications. This design allows independent transaction chains to progress concurrently, unlocking massive throughput improvements. By eliminating the need for a global state or sequential processing, the virtual mempool creates a scalable foundation for Bitcoin-native applications.

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Transaction chains

When activity remains in the offchain environment, each transaction’s outputs become immediately spendable, so wallets can submit follow-up transactions that consume those fresh VTXOs without waiting for onchain confirmation. Repeating this process links payments together: every new spend references the latest VTXO(s) from the prior step and produces new ones, forming a chain of transactions. ie., a path through the DAG. As long as each hop is validated and cosigned, the chain can extend arbitrarily, enabling multi-hop operations that execute in near-real time. tx-chain.png Because these chains live entirely in the virtual mempool, they progress at operator/signature latency rather than block times. Dependencies are explicit in the DAG, so invalid or conflicting hops are rejected and any downstream edges depending on them cannot execute. Users and applications can keep chaining until they choose to settle, at which point some or all of the path can be materialized on Bitcoin.
Long transaction chains raise exit cost and can therefore make a unilateral exit economically unviable, as all VTXOs of the respective chain need to be broadcast in the event of a unilateral exit.
Settling VTXOs that are part of long transaction chains via a batch swap solves the issue, as the new VTXO is a direct leaf of a batch output.

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Arkade Script

Arkade Script is an enhanced scripting environment that extends Bitcoin Script with additional capabilities for expressive, stateful contract logic. It introduces new primitives for introspection, arithmetic, and asset operations, enabling developers to build complex offchain applications directly tied to Bitcoin outputs. While Bitcoin Script prioritizes minimalism and security, Arkade Script expands the design space for preconfirmation computation without requiring any changes to Bitcoin consensus. All contracts ultimately settle via standard Bitcoin scripts, ensuring compatibility with Bitcoin’s trust model.

Arkade Script - Contracts

Explore tapscript opcodes for Bitcoin smart contracts in the Arkade ecosystem
Arkade Script is an extended version of Bitcoin Script, unlocking programmability via offchain execution.