MultiversX Protocol Expertise

This skill encompasses deep knowledge of the core MultiversX protocol architecture, utilized for reviewing protocol-level changes, complex dApp architectures involving cross-shard logic, and sovereign chain integrations.

1. Core Architecture: Adaptive State Sharding

• Sharding Types:
  • Network Sharding: Nodes are distributed into shards.
  • Transaction Sharding: Transactions are processed by the shard containing the sender's account.
  • State Sharding: Each shard maintains a portion of the global state (account space).
• Metachain:
  • The coordinator shard.
  • Handles: Validator churning, Epoch/Round verification, Slashing, Header notarization.
  • Does NOT execute general smart contracts (except for system contracts like Staking, ESDT management).
• Cross-Shard Transactions:
  • Async (Process -> Relay -> Execute): Sender Shard processes TX -> Generates internal transaction (Scratchpad) -> Relayer -> Receiver Shard executes.
  • Atomicity: Cross-shard is atomic but asynchronous.

2. Consensus: Secure Proof of Stake (SPoS)

• Selection: Deterministic selection of validators based on stake + rating.
• BLS Signing: Validators sign proposed blocks using BLS multi-signatures.
• Finality: Instant finality (within seconds) due to PBFT-like consensus within the shard.

3. Token Standards (ESDT)

• Native Implementation: Tokens are NOT smart contracts (unlike ERC-20). They are part of the protocol account state.
• ESDT Properties:
  • CanFreeze: Protocol can freeze assets if configured.
  • CanWipe: Protocol can wipe assets if configured.
  • CanPause: Protocol can pause transfers.
• Roles:
  • ESDTRoleLocalMint: Allows minting.
  • ESDTRoleLocalBurn: Allows burning.

4. Sovereign Chains & Interoperability

• Sovereign Chains: Dedicated blockchains extending MultiversX.
  • Gateway Contract: Handles bridging between Mainchain and Sovereign Chain.
  • Settlement: Sovereign Chains settle proofs to the MultiversX Mainchain (acting as Layer 1).
• Interoperability Standards:
  • MIP-X: Monitor [MIPs] for latest standard adoption.

5. Transaction Processing

• Gas Schedule: Operations have deterministic costs.
• Built-in Functions:
  • ESDTTransfer: Direct transfer.
  • ESDTNFTTransfer: Transfer of SFT/NFT.
  • MultiESDTNFTTransfer: Batch transfer (often used for Contract calls).

6. Critical Checks for Protocol Developers

• Intra-shard vs Cross-shard:
  • Always assume a call might be cross-shard unless verified co-location.
  • Async: If logic depends on the result of a call to another address, it MUST be an Async Call (Callbacks).
• Reorg Handling:
  • Microservices must handle block rollbacks (Standard: wait for 'Finalized' status, or handle re-org events).