Dispatch ledger queries in the Dijkstra era

[palas]

Context

Route all Conway-onwards queries (constitution, governance state, DRep/SPO state and stake distributions, committee state, vote delegatees, proposals, ratification and future parameters, default votes and DRep delegations) through
caseShelleyToBabbageOrConwayEraOnwards with obtainCommonConstraints, so they work in Dijkstra as well. Also covers the treasury query in queryStateForBalancedTx, the stability-window constant and the next-epoch nonce computation.

How to trust this PR

One mechanical pattern applied thirteen times inside a single function (toConsensusQueryShelleyBased): each Conway-onwards query's continuation changes from const $ Some … to \w -> obtainCommonConstraints (convert w) $ Some …, which makes the same consensus query available in Dijkstra. The consensus query constructors themselves are untouched — no query logic changes, only the era gate widens. The pre-Conway error arms stay exactly as they were.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff
• Changelog fragment added in .changes/

[Copilot]

Pull request overview

This PR widens the era gate for Conway-onwards ledger queries so they dispatch correctly in the Dijkstra era as well, by routing the Conway-onwards continuations through obtainCommonConstraints (via Convert (convert)).

Changes:

• Updated toConsensusQueryShelleyBased to wrap Conway-era-onwards query continuations with obtainCommonConstraints (convert w) so the same consensus queries are available in Dijkstra.
• Added a Herald changelog fragment documenting the newly supported Dijkstra-era behavior for these queries.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs	Broadens Conway-onwards query dispatch to include Dijkstra by obtaining common constraints in the Conway-onwards branch.
.changes/20260822_030407_cardano-api_palas_dijkstra_ledger_queries.yml	Documents the change as a feature for cardano-api.

Suppressed comments (9)

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:665

• This error message says the query is only available in the Conway era, but the new era gate allows Conway-era-onwards (including Dijkstra). Update the message to match the actual availability.

      (const $ error "toConsensusQueryShelleyBased: QueryRatifyState is only available in the Conway era")
      ( \w ->
          obtainCommonConstraints (convert w) $ Some (consensusQueryInEraInMode era Consensus.GetRatifyState)

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:683

• This error message says the query is only available in the Conway era, but the new continuation supports Conway-era-onwards (including Dijkstra). Update the message to avoid implying it won’t work in Dijkstra.

      (const $ error "toConsensusQueryShelleyBased: QueryDRepState is only available in the Conway era")
      ( \w ->
          obtainCommonConstraints (convert w) $
            Some (consensusQueryInEraInMode era (Consensus.GetDRepState creds))

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:692

• This error message says the query is only available in the Conway era, but the era gate now allows Conway-era-onwards (including Dijkstra). Update the message to match the actual availability.

      ( const $
          error "toConsensusQueryShelleyBased: QueryDRepStakeDistr is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:702

• This error message says the query is only available in the Conway era, but the era gate now allows Conway-era-onwards (including Dijkstra). Update the message to avoid misleading users.

      ( const $
          error "toConsensusQueryShelleyBased: QuerySPOStakeDistr is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:712

• This error message says the query is only available in the Conway era, but the continuation now supports Conway-era-onwards (including Dijkstra). Update the message for accuracy.

      ( const $
          error "toConsensusQueryShelleyBased: QueryCommitteeMembersState is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:723

• This error message says the query is only available in the Conway era, but the continuation now supports Conway-era-onwards (including Dijkstra). Update the message for accuracy.

      ( const $
          error "toConsensusQueryShelleyBased: QueryStakeVoteDelegatees is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:740

• This error message says the query is only available in the Conway era, but the continuation now supports Conway-era-onwards (including Dijkstra). Update the message to match actual availability.

      ( const $
          error "toConsensusQueryShelleyBased: QueryProposals is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:754

• This error message says the query is only available in the Conway era, but the continuation now supports Conway-era-onwards (including Dijkstra). Update the message to avoid misleading users.

      ( const $
          error "toConsensusQueryShelleyBased: QueryStakePoolDefaultVote is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

cardano-api/src/Cardano/Api/Query/Internal/Type/QueryInMode.hs:765

• This error message says the query is only available in the Conway era, but the continuation now supports Conway-era-onwards (including Dijkstra). Update the message for accuracy.

      ( const $
          error "toConsensusQueryShelleyBased: GetDRepDelegations is only available in the Conway era"
      )
      ( \w ->
          obtainCommonConstraints (convert w) $

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.