# V2-BE-XXX: Implement Verification and Dispute Query Endpoints

[DevMuhdishaq]

Closes #360

Overview

This PR implements the V2 backend boundary for verification and dispute query endpoints while preserving smart-contract authority and maintaining rebuildable event-derived state, following the canonical Optimism/EVM V2 pipeline architecture.

Changes Made

Closes #363

1. Core Feature Implementation

• Added DataState enum to properly distinguish between observed, safe, and finalized data states
• Implemented round snapshots, aggregate weights, user positions, dispute state, and appeal deadline exposure
• All on-chain numeric values preserved as strings to maintain full precision
• Strictly read-only endpoints that cannot mutate protocol state, ensuring smart contracts remain the single source of truth
  Closes V2-BE-030 — Publish Versioned OpenAPI Schemas and Error Contracts #365

2. Database Changes

• New migration: 1769800400000-AddVerificationDisputeEnhancements.ts adds all required columns:
  • v2_project_verification_rounds: Added dataState, totalStake, totalEffectiveWeight, roundSnapshot, appealDeadline
  • v2_project_participant_positions: Added dataState
  • v2_project_disputes: Added dataState

3. API Enhancements

• Cursor-based pagination implemented for all list endpoints to avoid offset pagination issues
• Comprehensive input validation at all API boundaries
• Computed data states returned with every entity, based on chain's safe/finalized block heights
• All existing controller and service patterns maintained for consistency
  Closes V2-BE-026 — Implement Verification and Dispute Query Endpoints #366

4. Module Updates

• Updated verification module to inject required EventCheckpoint repository
• Updated disputes module to inject required EventCheckpoint repository
• Maintained proper separation of concerns and dependency injection patterns

Acceptance Criteria Mapping

Criterion	Evidence
Expose round snapshots, aggregate weights, user positions, dispute state, and appeal deadlines	Added all fields to entities; query services expose these via API

Audit of Overlapping Code

Reused

• Existing entity structures, controller patterns, and cursor pagination implementation
• Canonical event and projector infrastructure from V2 events module
• TypeORM module patterns and dependency injection setup

Replaced

• Basic in-memory filtering replaced with proper query-builder pagination
• Static data replaced with computed data states based on chain finality

Deprecated

• None - this is a clean-slate implementation as part of the V2 pipeline; no legacy code removed in this PR

Testing

• All existing unit and integration tests should pass
• Query endpoints have been validated for proper input validation and error handling
• Pagination works correctly with cursor encoding/decoding
• Data state calculation correctly reflects block height against chain checkpoints

Security Notes

• No secrets or production credentials added
• No floating-point token accounting introduced
• All untrusted input validated at API boundaries
• Least privilege principle maintained throughout
• Fails closed on incompatible configurations