How Gravity Works

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Gravity is a decentralized bridge that enables seamless token transfers between Ethereum and Cosmos-based blockchains. Unlike custodial bridges that rely on trusted third parties, Gravity operates in a trust-minimized manner—users only need to trust the security of the underlying Cosmos chain. This article breaks down how Gravity functions at a technical yet accessible level, covering its architecture, core components, transaction flow, and security mechanisms.

The Core Mechanism: Bridging Ethereum and Cosmos

At its heart, Gravity facilitates cross-chain interoperability by locking ERC20 tokens on Ethereum and minting equivalent tokens on Cosmos (and vice versa). This process ensures that no single entity controls user funds.

Here’s how a typical transfer works:

This two-way peg system ensures asset consistency without requiring centralized custody.

👉 Discover how decentralized bridges are transforming cross-chain liquidity.

Key Components of Gravity

Gravity consists of four main components working in tandem:

  1. Gravity.sol – An Ethereum smart contract that locks ERC20 tokens and executes outgoing transfers.
  2. Gravity Cosmos Module – A module built using the Cosmos SDK that handles token minting, burning, and event observation.
  3. Orchestrator – A node-level program run by validators to sign Ethereum-bound messages with their private keys.
  4. Relayer Network – Independent actors who monitor the system and submit data to Ethereum for profit.

Each component plays a critical role in maintaining decentralization and liveness.

Gravity.sol: The Ethereum Anchor

The Gravity.sol contract acts as the trust anchor on Ethereum. It stores locked ERC20 tokens and executes outgoing transfers when authorized by Cosmos validators.

Validators control Gravity.sol through a dynamic multisig mechanism based on their staking power. The contract maintains a checkpoint—a snapshot of the current validator set and their voting weights. For any action (e.g., submitting a batch), at least two-thirds of the validator set must sign off.

Key functions include:

All methods are public but require valid cryptographic signatures from the validator majority.

How Tokens Move: From Ethereum to Cosmos

When a user initiates a transfer from Ethereum to Cosmos:

  1. They call sendToCosmos on Gravity.sol, sending ERC20 tokens to the contract.
  2. The contract emits a SendToCosmosEvent containing the recipient address, token type, and amount.
  3. Validators running Ethereum full nodes monitor these events via their orchestrators, which watch the chain with a delay (EthBlockDelay) to ensure finality.
  4. Orchestrators sign the event and broadcast it to the Cosmos chain.
  5. Once two-thirds of validators have signed, the event is marked as "observed."
  6. The Gravity module then mints an equivalent amount of tokens on Cosmos for the specified recipient.

This process ensures strong security by leveraging Ethereum's finality and Cosmos' consensus model.

Batching Transactions: Efficiency from Cosmos to Ethereum

Transfers from Cosmos to Ethereum are processed in batches to minimize gas costs. Instead of submitting each transaction individually, multiple withdrawals are grouped into one Ethereum transaction.

Here’s how batching works:

Validators sign the batch via their orchestrators. Once two-thirds of signatures are collected, relayers can submit the batch to submitBatch on Gravity.sol.

After execution, Gravity.sol emits a TransactionBatchExecutedEvent, which triggers cleanup on the Cosmos side: completed batches are removed, and superseded batches are canceled (with transactions returned to the pool).

👉 Learn how efficient transaction batching reduces cross-chain costs.

Validator Set Updates and Consensus Sync

Since validator sets change over time due to delegation shifts, Gravity must keep its Ethereum-side checkpoint updated.

The process:

  1. A validator set update proposal is submitted on Cosmos.
  2. The Gravity module captures a snapshot of the current validator set.
  3. Validators sign this snapshot.
  4. Once two-thirds sign, a relayer submits it to updateValset on Gravity.sol.

Crucially, relayers decide whether enough signatures exist—since Gravity.sol doesn’t run a full Cosmos light client, it cannot independently verify updates.

Currently, there is no direct incentive for relayers to submit validator updates. Most chains deploy altruistic relayers for this purpose, though future upgrades may introduce rewards.

Security Through Slashing

Gravity’s security model hinges on slashing—penalizing malicious or non-responsive validators on the Cosmos chain.

There are two main slashing conditions:

Liveness Slashing

Validators must sign valid batches and validator set updates. Failure to do so within a grace period results in slashing for non-participation.

Misbehavior Slashing

If a validator signs a fake batch or fraudulent validator set update—one never produced by the chain—they can be reported via an evidence submission mechanism. Once verified, the validator is slashed, losing part of their staked tokens.

This dual slashing model aligns validator incentives with honest bridge operation.

Frequently Asked Questions

Q: Is Gravity a custodial bridge?
A: No. Gravity is fully non-custodial—users retain control of their assets at all times. Funds are locked in smart contracts, not held by intermediaries.

Q: What happens if Ethereum reorgs after a deposit?
A: The EthBlockDelay parameter ensures events are only processed after sufficient finality, reducing reorg risk.

Q: Can anyone become a relayer?
A: Yes. Relayers operate in a free market—they earn fees by submitting profitable batches but face no penalties for inactivity.

Q: How are fees distributed?
A: Fees attached to outgoing transactions go directly to the relayer who submits the batch, creating a competitive incentive structure.

Q: Does Gravity support all ERC20 tokens?
A: Yes, any ERC20 token can be bridged once it’s registered on the Gravity module.

Q: What prevents validators from stealing funds?
A: Slashing penalties and economic security—the cost of attacking exceeds potential gains, especially on well-staked chains.

👉 Explore secure cross-chain solutions powered by decentralized consensus.

Conclusion

Gravity represents a significant advancement in blockchain interoperability by combining Ethereum’s asset richness with Cosmos’ scalability and sovereignty. Its design emphasizes decentralization, security, and efficiency—leveraging slashing, batching, and validator coordination to create a robust bridge infrastructure.

By eliminating custodianship and aligning incentives through crypto-economic mechanisms, Gravity sets a high standard for trust-minimized cross-chain communication.

Core Keywords: Gravity bridge, Ethereum to Cosmos, cross-chain bridge, Cosmos SDK, ERC20 bridging, decentralized bridge, transaction batching, validator slashing