problems

The x/problems module is the on-chain registry of daqq problems. It does not implement any problem itself — it tracks which problem modules exist, the IDs they have been assigned, and whether each one is currently accepting submissions.

See the Problem System page for the overall design rationale.

What it stores

type Problem struct {
    ID           uint64
    Name         string      // unique across all problems (e.g. "random_circuit")
    ModuleName   string      // implementing Cosmos module name
    Kind         ProblemKind // BUILTIN for the MVP; WASM reserved for the future
    Enabled      bool        // false => no new submissions, history kept
    AddedAtRound uint64      // beacon round at which the problem became selectable
    Description  string
}

type Params struct {
    NextProblemID uint64      // monotonically increasing; IDs are never reused
}

State invariants:

IDs are assigned sequentially and never reused, even after a problem is disabled.
Name is unique across all problems, including disabled ones.
Problems are only added or toggled, never deleted.

How problem modules register themselves

Each problem module (e.g. x/random_circuit) calls ProblemsKeeper.RegisterProblem(ctx, name, moduleName, description) from its own InitGenesis. Register is idempotent on name, so re-running genesis (e.g. in tests or after quickstart:clean) is safe.

To make this work, the InitGenesis order in app/app_config.go puts problems before any problem module:

InitGenesis: []string{
    // ...
    problemsmoduletypes.ModuleName,
    randomcircuitmoduletypes.ModuleName,
}

Queries

Command	Purpose
`quantumchaind query problems params`	Show `NextProblemID`.
`quantumchaind query problems list-problems`	List every registered problem (paginated).
`quantumchaind query problems get-problem [id]`	Look up by numeric ID.
`quantumchaind query problems get-problem-by-name [name]`	Look up by unique name.

Disabling a problem

Disabling does not delete the entry — it only flips the enabled flag. The implementing module’s message handler is responsible for rejecting new submissions when its problem is disabled (ProblemsKeeper.IsEnabled(ctx, id)).

The flip itself is gov-gated: a MsgSetProblemEnabled is sent through x/gov as a regular governance proposal. On acceptance:

tx:
  body:
    messages:
      - "@type": /quantumchain.problems.v1.MsgSetProblemEnabled
        authority: "<gov module address>"
        id: 1
        enabled: false

Historical submissions to the now-disabled problem remain queryable.

Adding a new problem

New problems are added by:

Writing a new x/<your_problem> module that depends on BeaconKeeper.GetSeed and ProblemsKeeper.RegisterProblem.
Cutting a release with the new binary.
Submitting a software-upgrade gov proposal to roll the network onto the release.
On the upgrade height, the new module’s InitGenesis/upgrade handler runs RegisterProblem, and the registry entry appears.

See Problem System → Adding a new problem.

random_circuit quantumchain