### Problem Statement Spec Kit identifies contributed commands, templates, scripts, and hooks primarily by `name`. Names can collide across artifact kinds and source layers, and a name alone cannot reliably link a resolved artifact-stack layer to the exact manifest contribution that supplied it. Consumers such as `preset info --json`, `extension info --json`, and `specify artifact` need stable contribution identifiers and a join key that works across reinstalls and machines. ### Proposed Solution Introduce computed, opaque `id` fields for every command, template, script, and hook returned by public manifest/info APIs, plus a `lookupId` field on every resolved artifact-stack layer.\n\nFor named artifacts, derive IDs using:\n\n```text\n{layer}:{sourceId}:{kind}:{name}\n```\n\nUse `core`, `preset`, or `extension` for `layer`; `_` for the core source ID; and the preset or extension manifest ID for other sources. Use `command`, `template`, `script`, or `hook` for `kind`. Examples include `preset:speckit.core:command:speckit.plan`, `extension:speckit.git:template:pr-body`, and `core:_:command:speckit.constitution`.\n\nFor hooks, use `{eventName}:{command}` as the name component. If duplicate event/command hook entries are valid, add an appropriate stable discriminator or reject duplicates; do not use array position.\n\nCompute IDs at read, serialization, or resolution time rather than persisting them in authored or installed manifests. `lookupId` must exactly match the originating contribution's `id`. Preserve existing name-based behavior and document IDs as opaque strings. ### Alternatives Considered Install-time UUIDs are unsuitable because they differ across machines and reinstalls. Existing names are insufficient because they collide across sources and kinds. Content hashes are unsuitable because IDs would change whenever artifact content is edited. Array indexes are unsuitable for hooks because reordering entries would change their IDs.\n\nDo not use the existing integration manifest as the ID source; it tracks installed file hashes and paths rather than manifest contribution identity. ### Component Specify CLI (initialization, commands) ### AI Agent (if applicable) _No response_ ### Use Cases 1. A wizard can read an artifact stack and follow each layer's `lookupId` to the full contribution detail without re-parsing manifests.\n2. Developers on different machines can use identical IDs when reporting or diagnosing a contribution.\n3. Tooling can hash or cache resolved compositions using sets of `lookupId` values.\n4. Future JSON output for `preset info`, `extension info`, and `specify artifact` can expose consistent cross-references. ### Acceptance Criteria - [ ] Document the `layer:sourceId:kind:name` grammar and `lookupId` relationship in `extensions/EXTENSION-API-REFERENCE.md` and the preset API/manifest reference.\n- [ ] Public manifest/info representations expose computed `id` values for commands, templates, scripts, and hooks.\n- [ ] Hook IDs are deterministic and collision-free without install paths or list indexes.\n- [ ] Resolved artifact-stack layers expose `lookupId` equal to the corresponding contribution's `id`.\n- [ ] Identical manifest coordinates produce identical IDs across processes, machines, project locations, and reinstalls.\n- [ ] IDs do not depend on artifact contents, timestamps, manifest hashes, archive paths, or installation directories.\n- [ ] Existing `name` fields and name-based resolution remain unchanged.\n- [ ] Tests cover every source layer and artifact kind, hook uniqueness, resolver repeatability, lookup round-trips, and backward compatibility. ### Additional Context This request defines the ID contract only. Adding the JSON output surfaces themselves for `preset info --json`, `extension info --json`, or `specify artifact` is out of scope and will be handled separately. Changing precedence, resolution, installation, or uninstall behavior is also out of scope. Relevant implementation areas include the extension manifest schema and validation and `PresetResolver` composition handling. IDs must not expose install paths, secrets, or connection strings.