---
id: capability.wiki.engine-typed-extensions
name: Wiki Engine with Typed Extensions
summary: A small-core wiki engine realizing a stringent typed-extension framework that addresses all wiki use cases and lets each shard activate only the features it needs.
owner: shard-wiki
status: draft
domain: helix_forge
tags: [wiki, engine, typed-extensions, feature-activation, shard-wiki]

maturity:
  discovery:
    current: D3
    target: D5
    confidence: medium
    rationale: >
      Architecture authored (shard-wiki/spec/WikiEngineCoreArchitecture.md): small page-store
      kernel + typed-extension framework, per-shard activation, engine-as-canonical-mode-shard,
      and a conflict-mediation realization are explored. Detailed extension SDK/ABI and the API
      protocol remain (so D3 Explored, not yet D4/D5).
  availability:
    current: A0
    target: A4
    confidence: low
    rationale: >
      Planned. No engine kernel or extensions exist yet; informational/planning reuse only.

external_evidence:
  completeness:
    level: C0
    name: Absent
    confidence: low
    basis: scope_vs_intent_and_consumer_expectations
    satisfied_expectations: []
    broken_expectations:
      - engine core and typed-extension mechanism not yet designed in detail
    out_of_scope_expectations:
      - replacing other wiki engines or mandating one implementation
  reliability:
    level: R0
    confidence: low
    basis: consumer_quality_signals
    known_reliability_risks:
      - planning-stage capability

discovery:
  intent: >
    Provide shard-wiki's reference first-party shard backend: a small core + a stringent
    typed-extension framework covering all collected use cases, mediating conflicting
    requirements into an integrated whole, with per-shard activation (only what you need).
  includes:
    - a minimal engine kernel (page lifecycle, storage via the adapter contract, the typing mechanism)
    - typed extensions that declare contracts and compose
    - per-shard feature activation
  excludes:
    - replacing or mandating other wiki engines (it is one shard type among many)
    - a single canonical implementation for all wikis
  use_cases:
    - "shard-wiki UseCaseCatalog UC-08..UC-25 and the full catalog (the engine must cover all)"

availability:
  current_level: A0
  target_level: A4
  current_artifacts:
    - "shard-wiki/workplans/SHARD-WP-0013-wiki-engine-prep.md"
    - "shard-wiki/spec/WikiEngineCoreArchitecture.md"
  consumption_modes:
    - informational

relations:
  depends_on:
    - capability.wiki.adapter-contract
    - capability.wiki.page-model
  related_to:
    - capability.feature-control.evaluate
    - capability.authorization.policy-evaluate

evidence:
  documentation:
    - "shard-wiki/workplans/SHARD-WP-0013-wiki-engine-prep.md"

consumer_guidance:
  recommended_for:
    - planning a composable, feature-activatable native wiki engine
  not_recommended_for:
    - implementation reuse today (planning-stage)
  known_limitations:
    - architecture authored; extension SDK/ABI + API protocol still to design; not yet built

promotion_history:
  - date: "2026-06-15"
    dimension: discovery
    from: D2
    to: D3
    rationale: WikiEngineCoreArchitecture.md authored (kernel + typed-extension framework explored); INTENT amendment ratified.
    author: shard-wiki
---

# Wiki Engine with Typed Extensions

shard-wiki's planned reference first-party shard backend — a *canonical-mode shard* it
implements natively: a small core plus a stringent typed-extension framework addressing all
collected use cases, mediating conflicting requirements into a consistent whole, with per-shard
activation (activate only what you need). It is one shard type among many — not a replacement
for other engines. Per-shard activation is a candidate consumer of
`capability.feature-control.evaluate`.

## Assessment notes

### Discovery
Architecture authored: `shard-wiki/spec/WikiEngineCoreArchitecture.md` (small kernel +
typed-extension framework; engine = canonical-mode shard). INTENT amendment ratified
(2026-06-15, decision 84ffdb48). Extension SDK/ABI + API protocol are the next deliverables.

### Availability
Planning-stage; informational reuse only.