ERC20 Asset Precompile on Polkadot Hub Revive Is Not XC20-Equivalent: Missing Metadata & Events Block DeFi (DEX Frontends, Lending, Indexing)

[SoneVibe]

Summary

The current ERC20 Asset Precompile on Polkadot Hub Revive implements only a minimal ERC-20 subset and is not functionally equivalent to XC20 implementations used in production on Astar EVM and Moonbeam.

While sufficient for low-level token transfers and Uniswap V2 core logic, it cannot support real DeFi protocols (lending, modern DEX frontends, analytics, subgraphs) due to missing metadata and standard ERC-20 events.

This creates critical friction for Ethereum-native builders migrating to Revive.

Context

Follow-up to issue polkadot-developers/polkadot-docs#1452 (comment).

Parity documentation states:

“Pallet Asset Precompiles (like XC-20) exist”

However, the current implementation diverges significantly from XC20 as implemented and used in production on Astar and Moonbeam, where XC20 refers to full ERC-20-compatible interfaces exposing asset metadata and events to EVM.

Technical Clarification: Why This Is Not XC20

In Astar/Moonbeam, XC20 assets:

Expose name(), symbol(), decimals() via EVM
Emit standard Transfer and Approval events
Are indexable by The Graph and analytics tools
Are directly usable by:

• DEX frontends
• Lending protocols (Compound / Aave forks)
• Aggregators

The Revive ERC20 precompile:

Implements only:

• balanceOf
• transfer
• transferFrom
• approve
• allowance
• totalSupply

Does not implement ERC-20 metadata (name, symbol, decimals)
Does not emit standard ERC-20 events
Stores metadata only in Substrate storage, inaccessible to EVM

Reproduction

Calling metadata functions on the ERC20 precompile:

IERC20(token).name();
IERC20(token).symbol();
IERC20(token).decimals();

Results in:

Panic: OUT_OF_MEMORY (0x41)

This behavior is confirmed and documented.

Impact

1. Lending Protocols (Compound / Aave forks)

Cannot compute exchange rates without decimals()
Cannot create cTokens with proper metadata
Risk engines and liquidations fail

2. DEX Frontends

Standard UIs crash when querying metadata
Wallet integrations break
Poor UX for users and builders

3. Indexing & Analytics

Missing standard ERC-20 events
Subgraphs cannot index assets
TVL and volume analytics impossible

4. Ecosystem Fragmentation

Each protocol forced to deploy ad-hoc wrappers
No canonical asset representation
Liquidity fragmentation risk

Comparison

Network Asset Interface
Astar EVM XC20 full ERC-20 contracts
Moonbeam XC20 + WGLMR
Polkadot Hub Revive ERC-20 subset precompile

Proposed Solution

(Preferred, Proven in Astar/Moonbeam)

Deploy canonical XC20-style ERC-20 wrapper contracts for major assets:

USDT
USDC
Other high-liquidity Asset Hub tokens

Characteristics:

• Full ERC-20 interface
• Metadata & events
• Governed / system-owned
• Single canonical address per asset

Why This Matters

Without full ERC-20 compatibility:

Lending protocols cannot launch
Frontends break by default
Ethereum-native builders are blocked
Adoption of Revive as a DeFi hub is slowed

Providing XC20-equivalent infrastructure would immediately unlock:

DEXes
Lending
Aggregators
Indexing
A smooth Ethereum → Polkadot migration path

Closing

This is not a theoretical concern: XC20-style infrastructure is already proven in production on Astar and Moonbeam.

Astar doc reference links:

1. https://docs.astar.network/docs/learn/interoperability/xcm/building-with-xcm/create-xc20-assets/
2. https://docs.astar.network/docs/learn/interoperability/xcm/building-with-xcm/send-xc20-evm

Aligning Revive with this model would significantly accelerate real DeFi adoption on Polkadot Hub.

Submitted by:
Dennis Solar Fernandez
Founder SoneVibe Finance
@Real_Dennis_S_F
Active EVM DeFi builder on Polkadot Hub