diff --git a/internal/docrevision/pg_store.go b/internal/docrevision/pg_store.go
index 8c8cf96e..a710c122 100644
--- a/internal/docrevision/pg_store.go
+++ b/internal/docrevision/pg_store.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"time"
 
 	"chat-agent-system/internal/app/uow"
@@ -65,8 +66,12 @@ func (s *Service) hydrateDocLocked(ctx context.Context, docID string) error {
 			&sn.SourceKind, &sn.ActorUserID, &sn.ActorRef, &actorRaw, &sn.SourceRunID, &sn.CreatedAt); err != nil {
 			return err
 		}
-		_ = json.Unmarshal(blockRaw, &sn.BlockMap)
-		_ = json.Unmarshal(actorRaw, &sn.ActorSnapshot)
+		if err := json.Unmarshal(blockRaw, &sn.BlockMap); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal block_map for doc %s snapshot %d: %w", docID, sn.ID, err)
+		}
+		if err := json.Unmarshal(actorRaw, &sn.ActorSnapshot); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal actor_snapshot for doc %s snapshot %d: %w", docID, sn.ID, err)
+		}
 		snaps = append(snaps, snapRow{snap: sn})
 		shas[sn.ContentSHA256] = struct{}{}
 	}
@@ -141,8 +146,12 @@ func (s *Service) hydrateDocLocked(ctx context.Context, docID string) error {
 			&ev.EditSessionID, &ev.RequestID, &ev.IdempotencyKey, &ev.CreatedAt); err != nil {
 			return err
 		}
-		_ = json.Unmarshal(actorRaw, &ev.ActorSnapshot)
-		_ = json.Unmarshal(changeRaw, &ev.ChangeSet)
+		if err := json.Unmarshal(actorRaw, &ev.ActorSnapshot); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal actor_snapshot for doc %s event %d: %w", docID, ev.ID, err)
+		}
+		if err := json.Unmarshal(changeRaw, &ev.ChangeSet); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal change_set for doc %s event %d: %w", docID, ev.ID, err)
+		}
 		cp := ev
 		s.events[cp.ID] = &cp
 		if cp.IdempotencyKey != "" {
@@ -173,12 +182,24 @@ func (s *Service) hydrateDocLocked(ctx context.Context, docID string) error {
 			&rep.ModelSnapshot, &rep.PromptVersion, &factRaw, &rep.CorrectsReportID, &rep.RawJSON, &rep.CreatedAt); err != nil {
 			return err
 		}
-		_ = json.Unmarshal(sumRaw, &rep.Summary)
-		_ = json.Unmarshal(riskRaw, &rep.RiskItems)
-		_ = json.Unmarshal(projRaw, &rep.ProjectImpacts)
-		_ = json.Unmarshal(docRaw, &rep.DocumentImpacts)
-		_ = json.Unmarshal(qRaw, &rep.OpenQuestions)
-		_ = json.Unmarshal(factRaw, &rep.DeterministicFacts)
+		if err := json.Unmarshal(sumRaw, &rep.Summary); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal summary for doc %s report %d: %w", docID, rep.ID, err)
+		}
+		if err := json.Unmarshal(riskRaw, &rep.RiskItems); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal risk_items for doc %s report %d: %w", docID, rep.ID, err)
+		}
+		if err := json.Unmarshal(projRaw, &rep.ProjectImpacts); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal project_impacts for doc %s report %d: %w", docID, rep.ID, err)
+		}
+		if err := json.Unmarshal(docRaw, &rep.DocumentImpacts); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal document_impacts for doc %s report %d: %w", docID, rep.ID, err)
+		}
+		if err := json.Unmarshal(qRaw, &rep.OpenQuestions); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal open_questions for doc %s report %d: %w", docID, rep.ID, err)
+		}
+		if err := json.Unmarshal(factRaw, &rep.DeterministicFacts); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal deterministic_facts for doc %s report %d: %w", docID, rep.ID, err)
+		}
 		cp := rep
 		s.reports[cp.ID] = &cp
 		if cp.ID > s.nextRepID {
@@ -205,7 +226,9 @@ func (s *Service) hydrateDocLocked(ctx context.Context, docID string) error {
 			&c.CreatedAt, &c.DecidedAt); err != nil {
 			return err
 		}
-		_ = json.Unmarshal(actorRaw, &c.ActorSnapshot)
+		if err := json.Unmarshal(actorRaw, &c.ActorSnapshot); err != nil {
+			return fmt.Errorf("hydrateDocLocked: unmarshal actor_snapshot for doc %s candidate %d: %w", docID, c.ID, err)
+		}
 		cp := c
 		s.candidates[cp.ID] = &cp
 		if cp.ID > s.nextCandID {
diff --git a/internal/docrevision/pg_store_hydrate_corrupt_test.go b/internal/docrevision/pg_store_hydrate_corrupt_test.go
new file mode 100644
index 00000000..22506950
--- /dev/null
+++ b/internal/docrevision/pg_store_hydrate_corrupt_test.go
@@ -0,0 +1,68 @@
+package docrevision_test
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"chat-agent-system/internal/db"
+	"chat-agent-system/internal/docrevision"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func TestHydrateDocLocked_CorruptJSONBFailsExplicitly_PG(t *testing.T) {
+	dsn := db.SkipIfNoTestDatabaseURL(t)
+	ctx := context.Background()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer pool.Close()
+
+	var n int
+	if err := pool.QueryRow(ctx, `SELECT COUNT(*) FROM information_schema.tables WHERE table_name='document_snapshots'`).Scan(&n); err != nil || n == 0 {
+		t.Skip("document_snapshots table missing; migrate required")
+	}
+
+	docID := "doc_hydrate_corrupt_jsonb"
+	_, _ = pool.Exec(ctx, `DELETE FROM document_change_events WHERE doc_id=$1`, docID)
+	_, _ = pool.Exec(ctx, `DELETE FROM document_agent_candidates WHERE doc_id=$1`, docID)
+	_, _ = pool.Exec(ctx, `DELETE FROM document_change_reports WHERE doc_id=$1`, docID)
+	_, _ = pool.Exec(ctx, `DELETE FROM document_versions WHERE doc_id=$1`, docID)
+	_, _ = pool.Exec(ctx, `DELETE FROM document_snapshots WHERE doc_id=$1`, docID)
+
+	_, err = pool.Exec(ctx, `
+		INSERT INTO document_snapshots (
+			doc_id, content_sha256, parent_snapshot_id, block_map, source_kind,
+			actor_user_id, actor_ref, actor_snapshot, source_run_id, created_at
+		) VALUES (
+			$1, 'sha_corrupt_test', NULL, '{not-valid-json'::bytea, 'human',
+			1, 'tester', '{}'::jsonb, NULL, now()
+		)
+	`, docID)
+	if err != nil {
+		// Some schemas store block_map as jsonb (rejects invalid at insert). Fall back to casting via text.
+		_, err = pool.Exec(ctx, `
+			INSERT INTO document_snapshots (
+				doc_id, content_sha256, parent_snapshot_id, block_map, source_kind,
+				actor_user_id, actor_ref, actor_snapshot, source_run_id, created_at
+			) VALUES (
+				$1, 'sha_corrupt_test', NULL, convert_to('{not-valid-json', 'UTF8'), 'human',
+				1, 'tester', '{}'::jsonb, NULL, now()
+			)
+		`, docID)
+		if err != nil {
+			t.Skipf("cannot insert corrupt block_map for schema: %v", err)
+		}
+	}
+
+	svc := docrevision.NewService(pool)
+	_, err = svc.GetRevisionState(ctx, docID)
+	if err == nil {
+		t.Fatal("expected hydrate error for corrupt block_map JSONB")
+	}
+	if !strings.Contains(err.Error(), "hydrateDocLocked") || !strings.Contains(err.Error(), "block_map") {
+		t.Fatalf("expected explicit hydrate/block_map error, got: %v", err)
+	}
+}