ConfigKit/docs/internal/overview.md

Internal Component Overview

ConfigKit exposes one supported root configkit package. The root owns public named types, declaration comments, constructors, and explicit conversion/wrapper code. It delegates loading and frozen inspection to internal/engine through private state; public signatures and fields do not expose engine types.

Implemented component owners:

• internal/engine owns host and native-filesystem source acquisition, grouped strict composition and recursive precedence assembly, schema inspection, decoding, lifecycle coordination, callback auditing, provenance/history, passive source-context retention, secret resolution and bootstrap, and safe inspection rendering. It never imports the root package.
• Root Source, Filesystem, Input, Underlay, Path, Secret, records, lifecycle callbacks, results, and bootstrap reports are root-defined wrappers or records. Callback wrappers pass only live engine context during a callback; Result.Config is detached and its private inspection remains frozen independently.
• Root conversion files explicitly cross the path, record, callback, secret, and error boundaries. There are no public aliases, anonymous engine embeddings, or public engine bridge methods.
• internal/document owns the parser-independent ordered tree and cloning. internal/yaml is the sole upstream YAML adapter and parser/dumper boundary.
• Engine mechanism tests own source, composition, decoding, callback, provenance, source-context, secret, history, rendering, and bootstrap behavior. Root tests own public API compatibility, facade integration, documentation links, and dependency/public boundary checks. Consumer examples remain under examples/consumers.

Dependency direction is root to engine to document/YAML support. The root may import only internal/engine among project internal production packages; engine and its supporting packages do not import root. The root boundary test enforces these constraints and rejects exported aliases, fields, or signatures involving internal types.

The configuration contract owns implemented YAML and lifecycle semantics. The consumer adoption guide owns application guidance. The architecture policy owns contributor boundaries, and ADR 0006 records the facade decision. See the development guide for validation commands and release procedure for source-candidate gates.