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Assessments

Overview​

The Assessments contract manages evaluation of cover claims. Assessors are organised into groups, and each product type is assigned to the group that assesses claims for it. Assessors cast a vote for or against a claim, along with the rationale for their decision.

Assessments are started by the Claims contract when a claim is submitted.

For the process around claim assessment, see Claim Assessment.

Key Concepts​

Assessor Groups​

Assessors are members of the mutual who have been added to one or more assessor groups. A group holds the set of assessors who vote on a given kind of claim, and each product type maps to exactly one group.

An assessor can belong to several groups, and a group's metadata is stored on IPFS.

Assessment​

An assessment records the voting on a single claim.

struct Assessment {
    uint16 assessingGroupId;
    uint32 cooldownPeriod;
    uint32 start;
    uint32 votingEnd;
    uint8 acceptVotes;
    uint8 denyVotes;
}
FieldDescription
assessingGroupIdThe group assessing this claim.
cooldownPeriodTime after voting ends before the outcome is final.
startTimestamp when the assessment started.
votingEndTimestamp when voting closes.
acceptVotesNumber of votes to accept the claim.
denyVotesNumber of votes to deny the claim.

Each assessor holds one vote. The voting period is a minimum of three days, and can be extended or closed early.

Ballot​

A ballot records how an assessor voted.

struct Ballot {
    uint32 timestamp;
    bool support;
}

Assessors record the rationale for their decision as an IPFS hash, readable through getBallotsMetadata.

Status and Outcome​

enum AssessmentStatus { VOTING, COOLDOWN, FINALIZED }
enum AssessmentOutcome { PENDING, ACCEPTED, DENIED, DRAW }

The outcome stays PENDING until the cooldown period after votingEnd has passed. After that, more accept votes than deny votes gives ACCEPTED, more deny votes gives DENIED, and an equal number gives DRAW.

The cooldown period allows a vote to be undone before the outcome becomes final.

Mutative Functions​

castVote​

Casts an assessor's vote on a claim.

function castVote(uint claimId, bool voteSupport, bytes32 ipfsHash) external;
ParameterDescription
claimIdThe claim being voted on.
voteSupportTrue to accept the claim, false to deny it.
ipfsHashIPFS hash holding the rationale for the decision.
  • Behavior:
    • Requires the caller to be an assessor in the group assigned to the claim's product type.
    • Requires the voting period to still be open.
    • Each assessor can vote once per claim.
    • Emits VoteCast.

startAssessment​

Starts the assessment for a claim.

function startAssessment(uint claimId, uint productTypeId, uint cooldownPeriod) external;
ParameterDescription
claimIdThe claim to assess.
productTypeIdThe product type, which selects the assessing group.
cooldownPeriodTime after voting ends before the outcome is final.

Usage: Called by the Claims contract when a claim is submitted.

extendVotingPeriod​

Extends the voting period on a claim.

function extendVotingPeriod(uint claimId) external;

closeVotingEarly​

Closes voting before the voting period ends, once the outcome can no longer change.

function closeVotingEarly(uint claimId) external;

undoVotes​

Removes an assessor's votes from the given claims.

function undoVotes(uint assessorMemberId, uint[] calldata claimIds) external;
ParameterDescription
assessorMemberIdThe assessor whose votes are undone.
claimIdsThe claims to undo votes on.

Usage: Used to reverse a vote during the cooldown period, before the outcome becomes final.

Group management​

These functions are governance controlled.

function addAssessorsToGroup(uint[] calldata assessorMemberIds, uint groupId) external;
function removeAssessorFromGroup(uint assessorMemberId, uint groupId) external;
function removeAssessorFromAllGroups(uint assessorMemberId) external;
function setGroupMetadata(uint groupId, bytes32 ipfsMetadata) external;
function setAssessingGroupIdForProductTypes(uint[] calldata productTypeIds, uint groupId) external;

View Functions​

getAssessment​

Returns the assessment for a claim.

function getAssessment(uint claimId) external view returns (Assessment memory assessment);

ballotOf​

Returns an assessor's ballot on a claim.

function ballotOf(uint claimId, uint assessorMemberId) external view returns (Ballot memory);

getBallotsMetadata​

Returns the IPFS hash holding an assessor's rationale for their vote.

function getBallotsMetadata(uint claimId, uint assessorMemberId) external view returns (bytes32);

getAssessingGroupIdForProductType​

Returns the group that assesses claims for a product type.

function getAssessingGroupIdForProductType(uint productTypeId) external view returns (uint assessingGroupId);

Group views​

function getGroupsCount() external view returns (uint groupCount);
function getGroupAssessorCount(uint groupId) external view returns (uint assessorCount);
function getGroupAssessors(uint groupId) external view returns (uint[] memory assessorMemberIds);
function getGroupsData(uint[] calldata groupIds) external view returns (AssessmentGroupView[] memory groups);
function getGroupsForAssessor(uint assessorMemberId) external view returns (uint[] memory groupIds);
function isAssessor(uint assessorMemberId) external view returns (bool);
function isAssessorInGroup(uint assessorMemberId, uint groupId) external view returns (bool);

minVotingPeriod​

Returns the minimum voting period, in seconds.

function minVotingPeriod() external pure returns (uint);

Events​

  • AssessmentStarted: Emitted when an assessment is started for a claim.
  • VoteCast: Emitted when an assessor casts a vote.
  • VoteUndone: Emitted when a vote is removed.
  • VotingEndChanged: Emitted when the voting period is extended or closed early.
  • AssessorAddedToGroup / AssessorRemovedFromGroup: Emitted when group membership changes.
  • GroupMetadataSet: Emitted when a group's IPFS metadata is set.
  • AssessingGroupForProductTypeSet: Emitted when a product type is assigned to a group.

Frequently Asked Questions​

Who can vote on a claim?​

Assessors in the group assigned to the claim's product type. Each assessor holds one vote.

Do assessors stake NXM to vote?​

No. Voting power comes from being an assessor in the relevant group, and no NXM is staked or locked to vote.

Can a vote be changed?​

An assessor votes once per claim. A vote can be undone during the cooldown period, before the outcome becomes final.

When is a claim outcome final?​

Once the cooldown period after the voting end has passed. Until then the outcome reads as PENDING.

Disclaimer: This documentation provides a high-level overview of the Assessments contract. Always refer to the latest contract code and official resources when developing against the protocol.