Stacks Improvement Proposals.

A Stacks Improvement Proposal (SIP) is a design document that provides information to the greater Stacks ecosystem's participants concerning the design of the Stacks blockchain and its ongoing operation. Each SIP shall provide a clear and concise description of features, processes, and/or standards for the Stacks blockchain and its operators to adopt, with sufficient details provided such that a reasonable practitioner may use the document to create an independent but compatible implementation of the proposed improvement. SIPs are the canonical medium by which new features are proposed and des…

This proposal describes a mechanism for single-leader election using _proof-of-burn_ (PoB). Proof of burn is a mechanism for bootstrapping a new blockchain on top of an existing blockchain by rendering the tokens unspendable (i.e. "burning" them). Proof of burn is concerned with deciding which Stacks block miner (called _leader_ in this text) is elected for producing the next block, as well as deciding how to resolve conflicting transaction histories. The protocol assigns a score to each leader based on the fraction of tokens it burned, which is used to (1) probabilistically select the next le…

In order to support applications which require validation of some pieces of their logic, we present a smart contracting language for use with the Stacks blockchain. This smart contracting language can be used on the Stacks blockchain to support programatic control over digital assets within the Stacks blockchain (e.g., BNS names, Stacks tokens, etc.) While application-chains may use any smart-contract language that they like, this smart contracting language's VM will be a part of blockstack-core, and, as such, any blockstack-core node will be able to validate application chains using this smar…

This SIP describes the design of the Stacks peer network, used for relaying blocks, transactions, and routing information. The document describes both the overall protocol design and rationale, and provides descriptions of each message's wire format (where applicable).

Blockchain peers are replicated state machines, and as such, must maintain a materialized view of all of the state the transaction log represents in order to validate a subsequent transaction. The Stacks blockchain in particular not only maintains a materialized view of the state of every fork, but also requires miners to cryptographically commit to that view whenever they mine a block. This document describes a Merklized Adaptive Radix Forest (MARF), an authenticated index data structure for efficiently encoding a cryptographic commitment to blockchain state. The MARF's structure is part of t…

This SIP describes the structure, validation, and lifecycle for transactions and blocks in the Stacks blockchain, and describes how each peer maintains a materialized view of the effects of processing all state-transitions encoded in the blockchain's sequence of transactions. It presents the account model for the Stacks blockchain, and describes how accounts authorize and pay for processing transactions on the network.

This document describes the measured costs and asymptotic costs assessed for the execution of Clarity code. This will not specify the _constants_ associated with those asymptotic cost functions. Those constants will necessarily be measured via benchmark harnesses and regression analyses. Furthermore, the _analysis_ cost associated with this code will not be covered by this proposal. The asymptotic cost functions for Clarity functions are modifiable via an on-chain voting mechanism. This enables new native functions to be added to the language over time. This document also describes the memory…

This SIP proposes a new consensus algorithm, called Stacking, that uses the proof-of-work cryptocurrency of an established blockchain to secure a new blockchain. An economic benefit of the Stacking consensus algorithm is that the holders of the new cryptocurrency can earn a reward in a base cryptocurrency by actively participating in the consensus algorithm. This SIP proposes to change the mining mechanism of the Stacks blockchain. SIP-001 introduced proof-of-burn (PoB) where a base cryptocurrency is destroyed to participate in mining of a new cryptocurrency. This proposal argues that a new mi…

This document describes the measured costs and asymptotic costs assessed for parsing Clarity code into an abstract syntax tree (AST) and the static analysis of that Clarity code (type-checking and read-only enforcement). This will not specify the _constants_ associated with those asymptotic cost functions. Those constants will necessarily be measured via benchmark harnesses and regression analyses.

Non-fungible tokens or NFTs are digital assets registered on blockchain with unique identifiers and properties that distinguish them from each other. It should be possible to uniquely identify, own and transfer a non-fungible token. This SIP aims to provide a flexible and easy-to-implement standard that can be used by developers on the Stacks blockchain when creating their own NFTs. This standard only specifies a basic set of requirements, non-fungible tokens can have more features than what's specified in this standard.

Fungible tokens are digital assets that can be sent, received, combined, and divided. Most forms of cryptocurrencies are fungible tokens. They have become a building block of almost all blockchains. This SIP aims to provide a flexible and easy-to-implement standard that can be used by developers on the Stacks blockchain when creating their own tokens.

This standard aims to formalize a the commonly used traits to offer fungible or non-fungible tokens for sale, at a certain price in STX, from a non-custodial wallet.

The Stacks 2.0 blockchain artificially constrains block goodput in two consensus-critical ways: it assesses storage costs for lists based on their maximum length instead of actual length, and it constrains the number of indexed I/O operations well below what the reference implementation is capable of handling. Changing either of these is breaking change, which requires a network-wide upgrade. This SIP proposes executing a breaking change to not only address these two constraints, but also to update all Clarity cost functions to more accurately reflect their true performance. The breaking chang…

Semi-Fungible Tokens, or SFTs, are digital assets that sit between fungible and non-fungible tokens. Fungible tokens are directly interchangeable, can be received, sent, and divided. Non-fungible tokens each have a unique identifier that distinguishes them from each other. Semi-fungible tokens have both an identifier and an amount. This SIP describes the SFT trait and provides a reference implementation.

This SIP proposes a set of updates to three major areas of the Stacks blockchain: Stacking, the Proof-of-Transfer (PoX) consensus algorithm as implemented in the Stacks chain and originally proposed in SIP-007. The proposed changes improve the user and developer experience of participating in Stacking, and add support for new behaviors and PoX reward address types. Clarity, the smart contract language supported on the Stacks blockchain. The proposed changes fix bugs and add new native functions and global variables that improve its support for interacting with off-chain services and blockchain…