# Vote By Signature

The `castVoteBySig` function allows an offline signer to participate in Onyx governance voting by submitting a digitally signed vote. Unlike the castVote function, which requires the voter to be online and execute the transaction, this function enables voting via an EIP-712-compliant signature, making it useful for delegated and gasless voting.

### Function Implementation in `CHNGovernance`

The `castVoteBySig()` function ensures that votes can be cast securely and efficiently using off-chain signatures, reducing the need for direct blockchain interaction while maintaining the integrity of the voting process.

#### Function Signature

```
function castVoteBySig(
    uint proposalId,
    bool support,
    uint8 v,
    bytes32 r,
    bytes32 s
) public
```

**Parameters**

* `proposalId`: The unique identifier of the governance proposal on which the vote is being cast.
* `support`: A boolean value indicating the vote choice:
  * true → Vote in favor of the proposal (Yes)
  * false → Vote against the proposal (No)
* `v`: The recovery byte of the signature, used for ECDSA signature verification.
* `r`: First half of the ECDSA signature pair.
* `s`: Second half of the ECDSA signature pair.
* `RETURN:`The function does not return a value. If the proposal ID is invalid or the signature is not valid, the transaction reverts with an error.

#### Example Solidity Implementation

To cast a vote using Solidity, the `castVoteBySig()` function can be called from an instance of the `CHNGovernance` contract:

{% code overflow="wrap" %}

```
CHNGovernance gov = CHNGovernance(0x123...); // Contract address of CHNGovernance
gov.castVoteBySig(proposalId, true, v, r, s); // Voting in favor using an offline signature
```

{% endcode %}

#### Web3.js Implementation (v1.2.6)

For interacting with the `CHNGovernance` contract using Web3.js, the following example demonstrates how to cast a vote by signature:

{% code overflow="wrap" %}

```javascript
const tx = await gov.methods.castVoteBySig(proposalId, false, v, r, s).send({}); // Voting against using an offline signature
```

{% endcode %}

#### Technical Considerations

* The `castVoteBySig()` function is state-modifying and will incur gas costs.
* Votes are weighted based on the voting power at the moment the proposal became Active.
* EIP-712-compliant signatures ensure the security and authenticity of the vote.
* If the signature is invalid or does not match the voter's address, the transaction reverts with an error.
* This function allows users to sign a vote offline and have another address submit the vote on-chain, enabling gasless voting if subsidized by a third party.
* Governance interfaces and voting dashboards should support offline signing workflows to increase accessibility and voter participation.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.onyx.org/governance/vote-by-signature.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.