ConfigKit/docs/roadmap/deferred.md

Deferred Scope

This document owns intentionally excluded features, not a committed delivery plan. The architecture policy governs changes to these boundaries. Implemented behavior belongs in the configuration contract and consumer adoption in the consumer guide.

Explicit non-goals and deferred scope

General environment-variable configuration overlays are not supported. Typed secret references and explicit directory bootstrap are the environment convention. Literal credential configuration and implicit secret-directory discovery are unsupported.

The following remain deliberately excluded:

• automatic conf.d discovery;
• remote imports, arbitrary providers, and additional configuration formats;
• custom merge strategies, sequence merging, reset operators, multiple-parent inheritance, and cross-scope references;
• named overlay inheritance;
• parser-specific or custom structural-decoding extension APIs;
• generic dynamic-subtree conversion and module-registry APIs;
• automatic schema migrations;
• hot reload, runtime resource replacement, and remote resource validation;
• a bundled CLI framework or application commands; and
• configuration fingerprints.

Applications may build their own validate, effective-value, source, bootstrap, and explanation commands around the library. Broadening these boundaries requires concrete consumer evidence, compatibility review, and an explicit design change.

Effective configuration diffs are implemented over frozen successful-load inspections; their current comparison and disclosure contract is in the configuration contract, with consumer workflows in the adoption guide. Fingerprints remain deferred.

Built-in sibling inheritance using extends is implemented as described in the configuration contract. It is distinct from inheritance between selected overlay files, which remains excluded above.

Possible source-version follow-ups

Independent collection or subtree specification policies were outside the completed shared source-version feature and remain possible future work, with no committed delivery plan. Current source-version checks use one application-owned policy across participating documents. Reconsider independent policies if concrete consumer needs justify a separate design decision; this is not a permanent prohibition. The original request and its selected scope remain at e4270c9:docs/roadmap/promptkit-feature-request.md in Git history. Existing sequence-composition and cross-scope inheritance deferrals above also remain unchanged.

Deferred performance experiments

The completed performance audit left these internal optimization candidates for separate investigation:

• branch-local explanation replay instead of the current whole-tree replay;
• redesigning the private metadata-copy handoff while preserving detached public records;
• caching schema descriptors across loads; and
• indexing complex contributor-trace membership while preserving its equality rules and compact linked traces.

These are not committed implementation work. Reconsider them with evidence that the benefit justifies the ownership, retained-memory, or equivalence risks. The completed audit and implementation evidence are preserved in Git history at 8e91a2b under docs/roadmap/.