Free TON

Contest: PolkaDot↔FreeTON Bridge Implementation: Stage 3

Contest dates

  • Submission period : 6 calendar weeks after approving this proposal in the governance interface;
  • Judging period : 2 weeks after the submission period.

Short description

Implement Stage 3 of the winning architecture of the PolkaDot↔FreeTON Bridge Design and Architecture contest with the milestone “Transferring tokens between FreeTON ↔ Polkadot chains”.


Chained contest


  1. Send a simple message from FreeTON to Substrate-based blockchain
  2. Transferring tokens between FreeTON ↔ Polkadot chains
  3. Distribution of relayer responsibilities Begin the economy model implementation
  4. Staking, Rewards and slashing; Run Canary Network


A significant challenge of blockchains to date is their lack of interoperability. Once a developer builds their decentralized application on any particular platform, they’re generally locked into that platform with no opportunity to leverage any of the benefits of other blockchains.

We believe that the future of blockchain technology is to allow all major networks to interact with one another and to be able to share value and information.

Both ecosystems, Polkadot and FreeTON share these views and we want to add the possibility to interoperability through the cross-chain message passing (XCMP) protocol, thus we open up many opportunities for awesome projects in the market of DeFi.

Web3 Foundation is delivering a decentralized and fair internet where users control their own data, identity, and destiny. Building a bridge with flagship product Polkadot will allow FreeTON to reach a whole new level.

General requirements

  • Cross-chain message-passing protocol with censorship resistance
  • The protocol must have the ability to add methods of decentralized governance (proposals, voting, rewards, slashes)
  • The possibility of trustless and non-custodial transfer of value between networks
  • Open sources of documentation published at GitHub/GitLab or another open repository

Fair play

As per Procedural remarks on contests.

Evaluation criteria and winning conditions

Hard criteria

  • Distribution of relayer responsibilities
  • Commission calculation. Calculation gas amount for message without real commission payment
  • CLI tool for relayer’s keys generation
  • DevOps tools to run several relayer nodes
  • Documentation. Detailed structured documentation for development tools and step-by-step examples to prove deliverables of this stage

Soft criteria

  • Detailed and easily understandable charts explaining the architecture and business processes
  • Brevity
  • Mostly everyday English to facilitate understanding
  • Readiness to participate in the implementation of the solution in the next stage


  • Relay node source code:
    • Generating and publication of the VRF keys for the substrate blockchain
    • Generating and publication of the FreeTON key into the smart contracts
    • Getting a relayer status
  • FreeTON smart-contracts and Substrate blockchain code:
    • FreeTON smart-contracts and Substrate pallet for distribution of relayer responsibilities.
      • On the substrate side verification VRF results
      • On the FreeTON side verification signature using native FreeTON cryptography
    • FreeTON smart-contracts and Substrate pallet for commission calculation
  • DevOps tools:
    • Update CI/CD scripts to existing deploy tools repository
  • Link to documentation at Github/Gitlab or another open repository, with the obligatory backlink to your submission in the repository’s README

Winning conditions

  • Only the winners who have obtained a prize place in the previous stage of the contest are allowed to participate
  • To apply for the next stage of the competition, you need:
    • take a prize in one of the first three places
    • score at least 5 points in the voting from the jury


1 place ……………………….120 000 TON

2 place ……………………….90 000 TON

3 place ……………………….50 000 TON

Procedural remarks to jurors

As per Procedural remarks on contests.

Jury rewards

As per Procedural remarks on contests.

Governance rewards

As per Procedural remarks on contests.

Procedural reminders to all contestants

As per Procedural remarks on contests.