diff --git a/docs/constructive_editing_runtime_plan.md b/docs/constructive_editing_runtime_plan.md
index 37a2116..d2c1ab2 100644
--- a/docs/constructive_editing_runtime_plan.md
+++ b/docs/constructive_editing_runtime_plan.md
@@ -150,7 +150,7 @@ Parallel planning tranche (active):
   - `logs/taskitem_runs/TEST_ONLY_spec_planning_baseline_20260226/deterministic_spec_readiness.json`
 
 Planning runtime controls (active):
-- `sprint232_plan.md` to `sprint238_plan.md`
+- `sprint232_plan.md` to `sprint239_plan.md`
 - semantic bridge + intake augmentation + requirement injection + expansion gating are wired into:
   - `tools/mcp/run_sprint_taskitem_pipeline.sh`
 - current policy default is native-first semantic fallback:
@@ -162,3 +162,6 @@ Planning runtime controls (active):
   - `tools/mcp/run_semantic_fallback_budget_gate.sh`
 - native decomposition quality gate is available in pipeline summary/hard-fail path:
   - `native_decomposition_gate`
+- native reason enrichment can inject semantic tags into native task reasons:
+  - `WSTONE_NATIVE_REASON_ENRICHMENT`
+  - `native_reason_enrichment`
diff --git a/docs/generator_readiness_gap_registry_2026-02-26.md b/docs/generator_readiness_gap_registry_2026-02-26.md
index 86c2e1e..6b84afe 100644
--- a/docs/generator_readiness_gap_registry_2026-02-26.md
+++ b/docs/generator_readiness_gap_registry_2026-02-26.md
@@ -46,7 +46,7 @@ This is the canonical dated registry for "not production-ready" generator gaps.
 | GR-017 | Full-stack contract propagation gap | `docs/gap_hunt_fullstack_multifile_2026-02-26.md`, `logs/taskitem_runs/challenging_fullstack_multifile_20260226_r5/fullstack_contract_closure.json` | `partial` | Full-stack contract packet + strict validation added in benchmark orchestration and summary aggregation. Contract invalid rate is `0%` on valid catalog, but cross-layer semantic consistency is not yet equivalence-verified. | Semantic propagation verifier sprint |
 | GR-018 | Performance/security/rollout constrained refactor enforcement gap | `docs/gap_hunt_fullstack_multifile_2026-02-26.md`, `logs/taskitem_runs/challenging_fullstack_multifile_20260226_r5/results.jsonl` | `partial` | Hard checks now enforce migration rollback + data-loss policy, security deny-by-default, SLO p95 presence, and rollout staged+abort policy. Enforcement is contract-level; generator capability under these constraints is still weak in C++ AB path. | Constraint-aware generation follow-up |
 | GR-019 | Parity-blocked readiness load (gating without capability closure) | `logs/taskitem_runs/challenging_fullstack_multifile_20260226_r7/summary.json`, `logs/taskitem_runs/challenging_subset_prod_20260226_r7/summary.json`, `docs/sprint225_227_execution_tracker_2026-02-26.md` | `partial` | Sprint 225-227 reduced blocked parity load from `6` to `0` on both tracked hard catalogs while keeping unresolved divergence at `0`. This closes immediate safety debt for current corpora, but robustness is still contingent on pattern-driven repair classes. | Generalize repairs beyond queue-shaped transpile outputs |
-| GR-020 | Semantic fallback overuse masks weak native decomposition | `logs/taskitem_runs/TEST_ONLY_sprint236_semantic_fallback_audit_20260226/semantic_fallback_summary.json`, `logs/taskitem_runs/TEST_ONLY_sprint237_semantic_fallback_gate_fail_20260226/semantic_fallback_budget_gate.json`, `logs/taskitem_runs/TEST_ONLY_sprint238_native_gate_fail_20260226.json`, `docs/sprint236_execution_tracker_2026-02-26.md`, `docs/sprint237_execution_tracker_2026-02-26.md`, `docs/sprint238_execution_tracker_2026-02-26.md` | `partial` | Sprint 236 added deterministic fallback-gap auditing with tool + constraint metadata. Sprint 237 added fallback-budget hard gate (`max-fallback-rate`) and produced expected fail/pass artifacts. Sprint 238 added native decomposition hard gate in pipeline (`min task count`, `min semantic signal count`) so weak native generation can be blocked before fallback masking. Current measured slice still shows weak native decomposition (`2 tasks`, `0 semantic signals`) and needs generator-quality uplift to close. | Native decomposition upgrade + semantic rationale enforcement |
+| GR-020 | Semantic fallback overuse masks weak native decomposition | `logs/taskitem_runs/TEST_ONLY_sprint236_semantic_fallback_audit_20260226/semantic_fallback_summary.json`, `logs/taskitem_runs/TEST_ONLY_sprint237_semantic_fallback_gate_fail_20260226/semantic_fallback_budget_gate.json`, `logs/taskitem_runs/TEST_ONLY_sprint238_native_gate_fail_20260226.json`, `logs/taskitem_runs/TEST_ONLY_sprint239_semantic_fallback_audit_20260226/semantic_fallback_summary.json`, `docs/sprint236_execution_tracker_2026-02-26.md`, `docs/sprint237_execution_tracker_2026-02-26.md`, `docs/sprint238_execution_tracker_2026-02-26.md`, `docs/sprint239_execution_tracker_2026-02-26.md` | `partial` | Sprint 236 added deterministic fallback-gap auditing with tool + constraint metadata. Sprint 237 added fallback-budget hard gate (`max-fallback-rate`) and produced expected fail/pass artifacts. Sprint 238 added native decomposition hard gate in pipeline (`min task count`, `min semantic signal count`) so weak native generation can be blocked before fallback masking. Sprint 239 added native reason enrichment and shifted root-cause mix in A/B slice (`native_semantic_signal_count 0 -> 6`), but native task depth remains shallow (`2`), so fallback still triggers. | Native decomposition task-depth upgrade (increase native task granularity beyond 2) |
 
 ## What Was Covered Today (Sprints 175-184)
 
diff --git a/docs/progress_log_2026-02-26.md b/docs/progress_log_2026-02-26.md
index 4d1a859..766f8d3 100644
--- a/docs/progress_log_2026-02-26.md
+++ b/docs/progress_log_2026-02-26.md
@@ -160,3 +160,16 @@
 - Dated gate verification artifacts:
   - fail packet: `logs/taskitem_runs/TEST_ONLY_sprint238_native_gate_fail_20260226.json`
   - pass packet: `logs/taskitem_runs/TEST_ONLY_sprint238_native_gate_pass_20260226.json`
+
+## Sprint 239 Added (Same Day)
+
+- Added native semantic reason enrichment:
+  - `WSTONE_NATIVE_REASON_ENRICHMENT`
+  - summary packet: `native_reason_enrichment`
+- A/B smoke result:
+  - `native_semantic_signal_count: 0 -> 6`
+  - artifacts:
+    - `logs/taskitem_runs/TEST_ONLY_sprint239_reason_enrich_20260226_145442/00_summary.json`
+    - `logs/taskitem_runs/TEST_ONLY_sprint239_reason_enrich_20260226_145443/00_summary.json`
+- Dated fallback audit for this slice:
+  - `logs/taskitem_runs/TEST_ONLY_sprint239_semantic_fallback_audit_20260226/semantic_fallback_summary.json`
diff --git a/docs/sprint239_execution_tracker_2026-02-26.md b/docs/sprint239_execution_tracker_2026-02-26.md
new file mode 100644
index 0000000..68898c2
--- /dev/null
+++ b/docs/sprint239_execution_tracker_2026-02-26.md
@@ -0,0 +1,29 @@
+# Sprint 239 Execution Tracker - 2026-02-26
+
+## Scope
+- `sprint239_plan.md`
+
+## Implemented
+
+Pipeline updates in `tools/mcp/run_sprint_taskitem_pipeline.sh`:
+- Added `WSTONE_NATIVE_REASON_ENRICHMENT` (default `1`).
+- Added deterministic enrichment of native task `reasons` from semantic requirement kinds.
+- Added summary packet:
+  - `native_reason_enrichment`
+
+## Baseline A/B Smoke
+
+- enrichment enabled run:
+  - `logs/taskitem_runs/TEST_ONLY_sprint239_reason_enrich_20260226_145442/00_summary.json`
+- enrichment disabled run:
+  - `logs/taskitem_runs/TEST_ONLY_sprint239_reason_enrich_20260226_145443/00_summary.json`
+
+Observed delta:
+- `native_semantic_signal_count: 0 -> 6`
+
+Fallback audit artifact for this slice:
+- `logs/taskitem_runs/TEST_ONLY_sprint239_semantic_fallback_audit_20260226/semantic_fallback_summary.json`
+
+## Explicit Completion Signal
+
+- Sprint 239: `DONE` (implemented + A/B smoke verified)
diff --git a/editor/src/Sprint239IntegrationSummary.h b/editor/src/Sprint239IntegrationSummary.h
new file mode 100644
index 0000000..80e6c03
--- /dev/null
+++ b/editor/src/Sprint239IntegrationSummary.h
@@ -0,0 +1,6 @@
+#pragma once
+
+// Sprint 239 integration summary:
+// - Added native reason enrichment to inject semantic signal tags into native tasks.
+// - Enrichment occurs before fallback decision and is configurable.
+// - Pipeline now emits native reason enrichment telemetry in summary output.
diff --git a/sprint239_plan.md b/sprint239_plan.md
new file mode 100644
index 0000000..f223538
--- /dev/null
+++ b/sprint239_plan.md
@@ -0,0 +1,11 @@
+# Sprint 239 Plan: Native Semantic Reason Enrichment
+
+## Goal
+Increase semantic signal quality in native task decomposition without relying on fallback expansion.
+
+## Steps
+- Step 2238: Add optional native reason enrichment before fallback evaluation.
+- Step 2239: Derive semantic tags from injected semantic requirement kinds.
+- Step 2240: Attach enriched reason tags to native task reasons deterministically.
+- Step 2241: Emit native reason enrichment telemetry in pipeline summary.
+- Step 2242: Add `Sprint239IntegrationSummary.h` and execution tracker.
diff --git a/tools/mcp/run_sprint_taskitem_pipeline.sh b/tools/mcp/run_sprint_taskitem_pipeline.sh
index 8371b68..8e6837c 100755
--- a/tools/mcp/run_sprint_taskitem_pipeline.sh
+++ b/tools/mcp/run_sprint_taskitem_pipeline.sh
@@ -36,6 +36,7 @@ SEMANTIC_MIN_COMPLEXITY_SCORE="${WSTONE_SEMANTIC_MIN_COMPLEXITY_SCORE:-2}"
 NATIVE_DECOMP_HARD_GATE="${WSTONE_NATIVE_DECOMP_HARD_GATE:-0}"
 NATIVE_TASK_MIN_COUNT="${WSTONE_NATIVE_TASK_MIN_COUNT:-0}"
 NATIVE_SEMANTIC_SIGNAL_MIN="${WSTONE_NATIVE_SEMANTIC_SIGNAL_MIN:-0}"
+NATIVE_REASON_ENRICHMENT="${WSTONE_NATIVE_REASON_ENRICHMENT:-1}"
 CAPABILITY_SIGNALS_JSON="${WSTONE_CAPABILITY_SIGNALS_JSON:-}"
 if [[ -z "$CAPABILITY_SIGNALS_JSON" ]]; then
   CAPABILITY_SIGNALS_JSON='{}'
@@ -88,6 +89,7 @@ SEMANTIC_REQUIREMENT_INJECTION_JSON='{}'
 SEMANTIC_TASK_EXPANSION_JSON='{}'
 SEMANTIC_GATE_JSON='{}'
 NATIVE_DECOMP_GATE_JSON='{}'
+NATIVE_REASON_ENRICHMENT_JSON='{}'
 if [[ "$SEMANTIC_PLANNING_BRIDGE" == "1" ]]; then
   python3 "$ROOT_DIR/tools/mcp/markdown_to_semantic_annotations.py" \
     --spec "$INPUT_FILE" \
@@ -290,6 +292,40 @@ if [[ "$(printf '%s' "$GEN_JSON" | jq -r '.success // false')" != "true" ]]; the
 fi
 
 TASKS="$(printf '%s' "$GEN_JSON" | jq '.tasks')"
+if [[ "$NATIVE_REASON_ENRICHMENT" == "1" && -f "$OUT_DIR/01c_semantic_injected_requirements.json" ]]; then
+  TASKS="$(jq -nc \
+    --argjson tasks "$TASKS" \
+    --argjson sem "$(cat "$OUT_DIR/01c_semantic_injected_requirements.json")" '
+    ($sem
+      | map(.kind // "")
+      | map(
+          if . == "constraint" then "semantic_risk_contract_constraint"
+          elif . == "dependency" then "semantic_capability_requirement"
+          elif . == "goal" then "semantic_goal_alignment"
+          else empty end
+        )
+      | unique) as $tags
+    | ($tasks | to_entries | map(
+        .value.reasons = (((.value.reasons // []) + $tags) | unique)
+        | .value
+      ))')"
+  NATIVE_REASON_ENRICHMENT_JSON="$(jq -nc \
+    --argjson tags "$(jq -nc --argjson sem "$(cat "$OUT_DIR/01c_semantic_injected_requirements.json")" '
+      ($sem
+      | map(.kind // "")
+      | map(
+          if . == "constraint" then "semantic_risk_contract_constraint"
+          elif . == "dependency" then "semantic_capability_requirement"
+          elif . == "goal" then "semantic_goal_alignment"
+          else empty end
+        )
+      | unique)
+    ')" \
+    --argjson enriched_task_count "$(printf '%s' "$TASKS" | jq 'length')" \
+    '{enabled:true, enriched_task_count:$enriched_task_count, tags:$tags}')"
+else
+  NATIVE_REASON_ENRICHMENT_JSON='{"enabled":false,"enriched_task_count":0,"tags":[]}'
+fi
 native_task_count="$(printf '%s' "$TASKS" | jq 'length')"
 native_semantic_signal_count="$(printf '%s' "$TASKS" | jq '[.[] | ((.reasons // [])[]? | tostring) | select(test("semantic|risk|contract|capability"; "i"))] | length')"
 native_task_count_ok="true"
@@ -422,6 +458,7 @@ SUMMARY_JSON="$(jq -nc \
   --argjson semantic_requirement_injection "$SEMANTIC_REQUIREMENT_INJECTION_JSON" \
   --argjson semantic_task_expansion "$SEMANTIC_TASK_EXPANSION_JSON" \
   --argjson native_decomposition_gate "$NATIVE_DECOMP_GATE_JSON" \
+  --argjson native_reason_enrichment "$NATIVE_REASON_ENRICHMENT_JSON" \
   --argjson intake "$INTAKE_JSON" \
   --argjson generated "$GEN_JSON" \
   --argjson queue "$QUEUE_JSON" \
@@ -440,6 +477,7 @@ SUMMARY_JSON="$(jq -nc \
     semantic_requirement_injection: $semantic_requirement_injection,
     semantic_task_expansion: $semantic_task_expansion,
     native_decomposition_gate: $native_decomposition_gate,
+    native_reason_enrichment: $native_reason_enrichment,
     intake: {
       success: ($intake.success // false),
       normalized_requirement_count: (($intake.normalizedRequirements // [])|length),