# MONAD-MEMPOOL: Local Validator Mempools Source: https://www.eipsfordesigners.com/standards/MONAD-MEMPOOL Agent brief: https://www.eipsfordesigners.com/standards/MONAD-MEMPOOL/agent.md Machine-readable JSON: https://www.eipsfordesigners.com/api/standards/MONAD-MEMPOOL Last reviewed: 2026-05-25 Last updated: 2026-05-25 | Field | Value | | --- | --- | | Status | Active | | Chain | monad | | Category | Security & Trust | | Journey stages | Reading & Understanding, Executing Transactions | | Detailed guide | Yes | | Official specification | https://docs.monad.xyz | ## UX Impact No global mempool — transactions go directly to upcoming block leaders, reducing MEV and improving inclusion times. Design implications: remove 'pending in mempool' states (transactions either included or not), no sandwich attack warnings needed, use lower default slippage (0.5% vs 1-3%), show confident price quotes without 'may change due to MEV' caveats. Design decisions: remove MEV protection toggles entirely (cleaner) vs. keep for cross-chain consistency; how to explain faster inclusion without complex mempool concepts. ## Summary No global mempool — transactions go directly to upcoming block leaders, reducing MEV and improving inclusion times. ## For Designers - You can remove MEV protection toggles on Monad-native swap flows. - Your default slippage can start at 0.5% not 1-3% with clear explanation on Monad. - You can simplify pending to Submitting → Included without mempool pending stage. ## Applicability ### When to Use - Monad-native DeFi and swap products. - Designing slippage and MEV copy for Monad. - Transaction status UX on Monad. ### When to Avoid - Cross-chain flows where Ethereum MEV still applies. - Ethereum-only interfaces. ## Problems It Solves ### Scary MEV copy on every swap Impact: high Old way: May be frontrun warnings everywhere New way: Clean quotes on Monad-native swaps ### Inflated slippage defaults Impact: medium Old way: 1-3% for Ethereum MEV New way: 0.5% default on Monad ### Misleading mempool pending UI Impact: medium Old way: Pending in mempool state never resolves same way New way: Submitting → Included binary ## Anti-Patterns ### MEV protection toggle on Monad swaps Severity: high Implies Ethereum mempool model Instead: Remove toggle; clean quote UI ### Pending in public mempool copy Severity: high State does not exist on Monad Instead: Submitting → Included ### 3% default slippage on Monad Severity: medium Unnecessary user cost Instead: 0.5% default with advanced override ## Design Decisions ### Keep MEV toggle for parity? Recommendation: Remove on Monad; keep on Ethereum cross-chain views. Rationale: Dead toggle erodes trust. ### Default slippage? Recommendation: 0.5% Monad; preserve higher default on Ethereum. Rationale: Match risk profile to mempool model. ### Explain no mempool to users? Recommendation: Only in help doc — not swap form. Rationale: Outcome is simpler UX not lecture. ## States to Design ### Submitting Trigger: Tx broadcast. User need: Brief wait. Design response: Submitting — not mempool pending. ### Included fast Trigger: Leader includes tx. User need: Quick success. Design response: Included within sub-second UX. ### Not included retry Trigger: Tx dropped not included. User need: Retry path. Design response: Not included — retry with explanation not mempool stuck. ### Swap on Monad Trigger: DeFi flow. User need: Simple slippage. Design response: 0.5% default; no MEV toggle. ### Cross-chain bridge in Trigger: Asset from Ethereum. User need: MEV context if relevant. Design response: Ethereum leg may differ — show on bridge source only. ## Vocabulary - Use "Submitting" instead of "Pending in mempool": Accurate Monad state. - Use "Included" instead of "Mined from mempool": Leader inclusion language. - Use "Slippage tolerance" instead of "MEV protection buffer": Standard DeFi term. ## What to Prototype First ### Swap with Monad slippage defaults Lower slippage safe without global mempool. Covers: 0.5% default, User raises slippage - Default 0.5% chip - Explain why lower on Monad - Advanced override ### Simplified pending states No mempool pending phase. Covers: Submitting, Included, Failed - Two-step status - No mempool pending label ### DeFi settings without MEV toggle Remove dead controls on Monad. Covers: Monad network, Ethereum network compare - Clean settings on Monad - MEV section only on Ethereum ### Price quote confidence Quotes without MEV caveat clutter. Covers: Quote display - Clean quote - No may be sandwiched footnote on Monad ## Mental Model ### No global mempool Txs not publicly visible pre-inclusion — different from Ethereum. ### Direct to leader Faster inclusion path — less pending limbo. ### Reduced sandwich Not zero everywhere — but Monad-native swaps simpler. ### Slippage Can be tighter by default on Monad. ### Cross-chain caveat Bridges from Ethereum still have Ethereum MEV rules. ## Seen in the Wild - Uniswap: Slippage and MEV settings reference — simplify on Monad. (https://app.uniswap.org/) - CowSwap: MEV-aware UX contrast for Ethereum. (https://cow.fi/) - Monad docs: Local mempool architecture context. (https://docs.monad.xyz/) ## On Monad ### Mempool model Ethereum: Global public mempool MEV surface Monad: Local validator mempools direct to leader Design implication: Remove MEV toggles; simplify pending on Monad. ### Slippage defaults Ethereum: 1-3% common for sandwich protection Monad: 0.5% reasonable default Design implication: Network-aware slippage presets. ### Inclusion time Ethereum: Mempool pending variable Monad: Fast leader inclusion Design implication: Binary submitting/included status. ## UX Patterns ### Monad Swap Defaults Lower slippage without MEV toggle. Components: SlippageChip, CleanQuote, SwapButton User flow: - Open swap on Monad - See 0.5% default - Quote clean - Confirm Mockup registry key: `eip-7702/one-click-swap` (React UI on the live standard page). ### Binary Inclusion Status No mempool pending stage. Components: SubmittingLabel, IncludedLabel User flow: - Submit - Submitting briefly - Included or retry Mockup registry key: `concept/tx-status` (React UI on the live standard page). ## Related Standards - MONAD-PARALLEL: Fast inclusion complements parallel execution - ERC-7683: Cross-chain still has source-chain MEV ## Technical Notes MONAD-MEMPOOL: no global mempool UX; remove MEV toggles and lower default slippage on Monad-native flows.