Spec Kitty

Phase 1 — Data Model

Mission mission-resolver-port-01KX1C05 · #2173 Phase-2. No persistent data model changes — this is a DI seam over existing reads. The "entities" here are the port interface and the value objects it moves.

Value objects (existing, reused unchanged)

ResolvedMission (context/mission_resolver.py:51, frozen)

Field	Type	Meaning
mission_id	str	26-char ULID from meta.json
mission_slug	str	kitty-specs/ directory name
feature_dir	Path	absolute mission directory
mid8	str	first 8 chars of mission_id

MissionExecutionContext (mission_runtime/context.py:262, frozen) — renamed from ExecutionContext (FR-012)

The pure composite the builder mints. Invariant: never carries an adapter (C-006). This mission renames the class from ExecutionContext to MissionExecutionContext (DDD ubiquitous language; also disambiguates from core/context_validation.py::ExecutionContext(StrEnum), which is NOT renamed) and makes its builder injectable at the shell.

New port interface

MissionResolver (Protocol) — defined in mission_runtime (shell owns its port)

Lives in mission_runtime/mission_resolver_port.py so the shell references a local type and no new mission_runtime → specify_cli.context layer-ledger edge is created (D-Q2 revised). Adapters import it downward via specify_cli → mission_runtime (package root).

class MissionResolver(Protocol):
    def resolve(self, handle: str) -> ResolvedMission: ...
    def all_missions(self) -> list[ResolvedMission]: ...

ambiguity → AmbiguousHandleError/MissionSelectorAmbiguous, cold-miss → MissionNotFoundError naming spec-kitty migrate backfill-identity. No is None/or slug fallback (D-05).

(doctrine_synthesizer/apply.py, vcs/detection.py) that scan for a matching mission_id.

• resolve(handle) — the identity resolution currently in resolve_mission; fail-closed-loud:
• all_missions() — the enumeration currently in _build_index, for the resolve-by-identity consumers
• Bound to a repo_root at construction (adapter concern), so callers pass only the handle.

FsMissionResolver — real adapter

anti-fold identity_audit.py consumer keeps its own walk — C-001).

• Wraps the existing _build_index(repo_root) walk + the resolve_mission priority ladder.
• Request-scoped; instance-lifetime memoization only, no module/process cache (C-005).
• Silently skips mission_id-less / non-dict-meta missions exactly as _build_index does today (so the

FakeMissionResolver — stub adapter

• Constructed from an in-memory list[ResolvedMission] (canonical-shaped fixtures — D-05).
• Zero filesystem access → enables the FS-free builder test (NFR-001).
• Same fail-closed contract: unknown handle → MissionNotFoundError; ambiguous → AmbiguousHandleError.

Injection seam (REVISED — thread from callers, not inside the assembler)

The seam is at the callers of _resolve_mission_slug (it runs before _assemble_core_fragments and feeds it), threaded through the canonicalizer chain to the single walk. The free resolve_mission gains an optional resolver param so no path bypasses it. Default constructed at the CLI/specify_cli boundary.

# specify_cli/context/mission_resolver.py — the ONE walk, now injectable
def resolve_mission(handle: str, repo_root: Path, *, resolver: MissionResolver | None = None) -> ResolvedMission:
    return (resolver or FsMissionResolver(repo_root)).resolve(handle)

# mission_runtime/resolution.py — shell threads a Protocol-typed resolver down (no context import)
def resolve_action_context(..., *, resolver: MissionResolver | None = None):
    slug = _resolve_mission_slug(..., resolver=resolver)   # → canonicalizer → resolve_mission(resolver=...)
    return _assemble_core_fragments(..., resolver=resolver)
# _resolve_mission_id keeps its legacy-<slug> bootstrap carve-out (D-07), NOT routed through resolve().
# build_execution_context(...) stays FS-free and takes NO resolver.

NFR-001 scope: the FS-free test drives the identity-resolution leg via the Fake; the assembler's other FS legs (get_main_repo_root, _resolve_coordination_branch, _resolve_status_surface_dir, topology) are separate ports deferred to later #2173 phases (D-09).

Out-of-model (anti-fold — NOT routed through the port)

• status/identity_audit.py — needs to see mission_id-less missions the resolver skips (C-001).
• merge/ordering.py — max(mission_number) aggregate over a caller-supplied non-primary scan root under the merge lock (C-002).
• core/paths.py:816/835 — best-effort swallow-and-degrade error listing (C-003).
• migration-time walks (C-004).