Epico: Ethereum Wallet Compatibility for Polkadot SDK Chains

Table of Contents

• TL;DR
• Interest Received
• Details
• What Epico Enables
• Demo
• Epico Limitations
• Ecosystem Impact and RoI
• Proposed Funding Model
• Scope of Work
• Out of Scope
• Our Past Work
• Duration and Timelines
• Contact
• Budget

TL;DR

Brief

We are seeking Polkadot Treasury’s support for the development and open source rollout of Epico — an Ethereum wallet compatibility layer for the Polkadot SDK. Epico will enable Polkadot SDK chains to seamlessly interface with Ethereum wallets — without the need for EVM emulation, or wallet plugins (snaps).

Scope of Delivery

• Epico source code
• Integration guides
• Technical Support for 3 months

Budget

$246,330 USDC

Interest Received

We announced Epico and published a recorded demo right before EthDenver 2025 (late February), and spoke with several parachain teams during and after EthDenver for potential integration of Epico in their chains. We have received interest from 5 teams so far, 3 of which are listed below and the other two didn’t wish to be named in the proposal.

• Mythos
• Frequency
• Polimec

As and when we publish the Epico source code and integration guide, we expect more teams to adopt the solution in their Polkadot SDK based chains.

We also received the following words of support from Mythos and Frequency:

“At Mythos, our mission is to lower the barriers to Web3 adoption starting with gaming, but extending to the broader ecosystem. A key part of that is meeting users where they already are. By enabling Ethereum RPC compatibility via Epico, on the Mythos parachain, we make it possible for millions of users to interact using wallets they already trust, while still benefiting from the throughput improvements of Substrate. This would significantly reduce friction and open up seamless access to the MYTH token, whether on Ethereum or within our parachain.” - Cameron Thacker, VP, Mythical Games

“The Frequency core contributors support this proposal. We believe there is a requirement for interoperability with the Ethereum community for the success and expansion of the Polkadot ecosystem. We also see this as a perfect pairing with the ongoing work on Pallet Revive. Epico has the chance to accelerate the rollout of Ethereum RPC compatibility for Frequency, a major goal for us this year. We have previously had great experiences with BlockDeep, including the code reviews they did for Frequency, and have confidence in BlockDeep’s ability to deliver the work for this proposal.” - Harry Evans, CTO, Project Liberty

Details

One of the largest barriers to mainstream adoption for Polkadot-based chains has been the unfamiliarity users face when interacting with Substrate-native accounts and wallets. The majority of crypto users today, especially those coming from Ethereum and EVM-compatible ecosystems, rely on MetaMask and other Ethereum-centric wallets as their default gateway into Web3.

The following graphs show absolute domination of MetaMask, sourced from Dune dashboard: Wallet War

Epico directly addresses this challenge by enabling users to sign and send transactions using their existing Ethereum wallets like MetaMask to Polkadot SDK chains, without needing to install snaps (plugins) or understand new account formats.

What Epico Enables

• MetaMask and Ethereum Wallet Support: With Epico, any Polkadot SDK chain that integrates the solution will allow users to connect using their Ethereum accounts and sign transactions via MetaMask and other Ethereum wallets — just as they would on any EVM chain.
• Familiar UX for New Users: Users will no longer need to manage separate Polkadot-specific accounts or learn new address formats. A single Ethereum wallet address can now interact with both Ethereum and Polkadot-based applications on chains that adopt Epico.
• Frictionless Onboarding: Whether a user is exploring DeFi, NFTs, games, or decentralized identity apps on Polkadot, Epico allows them to skip the typical onboarding hurdles like creating new wallets, backing up new seed phrases, or converting assets via bridges.

Demo

We integrated Epico with a solo-chain node and recorded the following fully functional demo. We encourage the community to take a look at the demo before casting their vote.

https://www.youtube.com/watch?v=CS74zbi9OYI 

Epico Limitations

[UPDATE]: In light of Polkadot SDK PR 8757, Substrate accounts can be deterministically represented as Ethereum addresses. As a result, Epico’s previous limitation of working only with native Ethereum accounts no longer applies.

In its current form, Epico focuses on enabling seamless interaction between MetaMask (and other Ethereum-compatible wallets) and Substrate-based chains. This is achieved by integrating chains that natively support Ethereum-style accounts (such as Mythos).

However, chains that exclusively use Substrate’s account format (AccountId32) do not yet benefit from Epico. To address this limitation, we’ve been actively exploring solutions that would allow Substrate chains to support Ethereum accounts while maintaining full backward compatibility with their existing native account systems.

One approach involves leveraging Ethereum accounts as proxies for Substrate accounts — a mechanism we have already successfully demonstrated in our smart accounts project, Otro.

Ecosystem Impact and RoI

Epico is built with one clear goal: to remove the invisible walls between the Polkadot and Ethereum ecosystems from the user's perspective.

By allowing users to access Polkadot-based chains and applications directly through MetaMask and other Ethereum-compatible wallets, Epico will:

• Make Polkadot-based apps immediately accessible to the largest wallet user base in the blockchain ecosystem.
• Reduce the learning curve and eliminate the need for new wallets, boosting adoption of both new and existing dApps built on Polkadot SDK.
• Encourage broader user engagement in the Polkadot ecosystem by removing the need for wallet switching.

Potential RoI

Epico is focused on improving user experience by enabling access to Polkadot-based apps using wallets people already use. MetaMask alone has over 30 million monthly active users (as on Jan 2024). With Epico, a good part, if not all, of those users will be able to use their Ethereum wallets to interact with Polkadot chains, without installing new tools or learning new formats.

This can lead to:

• More users trying and staying with apps built on Polkadot.
• Easier onboarding for dApps and better conversion from marketing efforts.
• Better cross-ecosystem liquidity and network effects.

Our strategy includes two parts:

• Build a reliable, well-documented tool that is easy to integrate.
• Work closely with parachains and dApp developers to promote real-world use cases and adoption.

Our goal is not just to publish code, but to enable meaningful adoption that brings more users and activity into the Polkadot ecosystem.

Proposed Funding Model

Our proposal differs slightly from most others seeking prospective or retrospective funding. Epico was built over the course of several months — from initial analysis and design to development and testing. It has been an iterative journey, during which we explored multiple approaches before arriving at a solution that truly works.

Once the technical work was complete, we began evaluating potential ways to sustain and distribute Epico. One option was to adopt a closed-source, per-integration licensing model, allowing teams building on Substrate to purchase access. The alternative was to open-source the project and rely on retrospective funding.

The first path would require significant time spent on sales cycles, which we felt would divert our focus away from what we do best — building and improving the technology. The second path risked turning the project into an unmaintained code dump if retrospective funding didn’t materialize, which would ultimately not result in a useful solution.

Instead, we’ve chosen a middle-ground approach: one that allows us to deliver polished, high-quality code while ensuring support and maintenance. We are committed to open-sourcing Epico under the Apache 2.0 license upon completion, giving the community full access to the codebase.

Upfront funding will enable us to finalize the remaining work: cleaning up the code, writing comprehensive documentation, conducting peer reviews, and ensuring alignment with ecosystem standards. This ensures the project will be released in a state that is truly useful, reliable, and maintainable from day one.

We believe open-sourcing without proper funding risks leaving behind incomplete or poorly documented code, which can create more confusion than value for the ecosystem. Our goal is to avoid that by releasing a professional, well-supported open-source project — not just publishing a code dump.

Scope of Work

• Completion of Epico core features. Open-sourcing of the entire codebase.
• Documentation, tutorials, and integration guides to streamline adoption by parachain and solo chain teams.
• Fully functional demo with Epico integration and a demo UI for anyone to try it out.
• Technical support/advisory for the first 3 months (after open sourcing) to any team who intends to integrate Epico in their chain.
• Maintenance and update to latest Polkadot SDK quarterly releases for at least 6 months.

 

Out of Scope

• Security audits are out of scope of this proposal. However, we will approach PAL for audits, or may create another proposal for that if needed.
• Development effort for integration with specific chains is out of scope, however we commit to providing technical support for integration as mentioned in the scope section above.

Our Past Work

In our ~1 year of operations so far, BlockDeep Labs has delivered the following to the Polkadot ecosystem:

• Development and migration of Mythos parachain (funded by DF program).
• Delivery of Ecosystem Services as part of our last treasury proposal.
  • In-depth code reviews for 20 teams
  • Detailed Polkadot SDK best practices book - Libro
  • Delivery Partners Program
  • Release analysis reports
• Development of Smart Account Abstraction and XCM Tracer.
• Currently under development - RFC-0097: Fast Unbonding of Staking rewards.
• Advisory to several pre-launch teams building in the ecosystem.

Duration and Timelines

• Epico source code, integration guides, documentation, and demo will be delivered within 3 months of this proposal passing.
• Technical support will be provided for 3 months after open sourcing the code.
• Maintenance and upgrades to Polkadot SDK quarterly releases will be provided for 6 months after open sourcing the code.

Contact

• Email: info@blockdeep.io
• Element (Technical Support): https://matrix.to/#/#epico-blockdeep:matrix.org
• Telegram: @web3gautam (Founder, BlockDeep)

Budget

This section outlines the scope of work completed, remaining tasks, and projected support requirements for the Epico project, along with associated costs.

Time and Resources

So far, we’ve already spent ~185 person-days (roughly 1.5 FTE for ~5 months) of effort on the tasks detailed in the section below. The FTE working on Epico are senior Rust engineers with experience on Substrate and Ethereum both. In addition, there was some oversight and architecture effort from a team lead/manager, and some PM effort for coordination.

Tasks Completed

• Detailed analysis of all standard Eth RPCs.
• Analysis of API calls made by MetaMask.
• Analysis of Frontier project and identification of reusable components for Ethereum signatures support.
• Designing Epico on-chain and off-chain (node side) components.
• Designing of Epico DApp side components (JavaScript snippets).
• Solving efficient storage for transaction receipts. This was a heavy design effort considering Substrate does not have transaction receipts by design.
• Detailed analysis of Ethereum Gas and Substrate Weights, and a conversion mechanism for RPC APIs. This required quite a bit of trial and error to find the right conversion ratio. We wrote a detailed blog post about it too.
• Development and in-depth testing of all components:
  • RPC implementation
  • Gas conversion
  • Transaction wrapper
  • Signature verification
  • Transaction receipts
• Integration with parachain and solochain node templates.
• Reorganizing and packaging rust code into easily usable crates.
• Building an end to end demo for users to click through and try.

Future Tasks

We require another 20 person-days of effort for the following tasks:

• Code reviews (not security audits)
• Documentation and integration guides
• Polishing and deployment of the demo

In the future, to provide technical support to teams integrating Epico in their chains, we estimate a total of 25 person-days of effort spread over a 3 month period.

Cost Estimates

Total Effort: 230 person-days

Daily Rate: USD 900 (~ EUR 800 per day or EUR 100 per hour)

Sub Total (230*900): $207,000
A detailed breakdown of the budget is available here.

German VAT at 19%: $39,330
Note about VAT: BlockDeep is a German company, with registered address in Berlin. We have to report all company income in our VAT returns as per law. Considering, in this case, the recipient of our services is Polkadot Network Treasury, which is a decentralized entity without any registered address, we have to report and file full VAT for this treasury payment. Please see a relevant discussion on this Polkadot forum post, which is also applicable for other EU countries.

Total: $246,330 USDC

Thank you for considering our proposal. We're happy to answer any questions and provide further details as needed. Looking forward to engaging with the community and moving Epico forward together.