diff --git a/src/main/api-server/routes-files.ts b/src/main/api-server/routes-files.ts
index db5a8545..bae02baf 100644
--- a/src/main/api-server/routes-files.ts
+++ b/src/main/api-server/routes-files.ts
@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { IMPORTANT_DOC_TYPE_SET } from "@shared/document-categories";
 import { requireParam, type AgentApiServer } from "./server-core";
 
 type DocumentRow = {
@@ -133,8 +134,7 @@ export function registerFileRoutes(server: AgentApiServer) {
     // Deliverable review gate: check at document creation time (most reliable).
     // In ai_cofounder mode, checkpoint-engine handles document reviews via the
     // onDocumentCreated callback, so skip the direct approval here to avoid duplicates.
-    const IMPORTANT_DOC_TYPES = new Set(["prd","technical_spec","design_doc","project_brief","proposal","budget_proposal","architecture_decision","contract","sop"]);
-    if (IMPORTANT_DOC_TYPES.has(docType)) {
+    if (IMPORTANT_DOC_TYPE_SET.has(docType)) {
       try {
         const companySettings = db.getCompanyApprovalSettings(token.companyId);
         const company = companySettings ? { reviewDeliverables: companySettings.reviewDeliverables } : null;
diff --git a/src/main/api-server/routes-tasks.ts b/src/main/api-server/routes-tasks.ts
index 6bd08edc..4370fd81 100644
--- a/src/main/api-server/routes-tasks.ts
+++ b/src/main/api-server/routes-tasks.ts
@@ -1,5 +1,6 @@
 import { z } from "zod";
 import { taskInputSchema } from "@shared/contracts";
+import { IMPORTANT_DOC_TYPES } from "@shared/document-categories";
 import { canAssignTask, canUpdateTask } from "../agent-permissions";
 import { inferTaskType } from "../connector-matching";
 import { validateTaskCreation } from "../task-quality-gates";
@@ -138,7 +139,7 @@ export function registerTaskRoutes(server: AgentApiServer) {
       // Deliverable review gate: intercept agent trying to advance a flagged task to "done".
       // This MUST succeed — silently skipping review would let unreviewed work advance.
       if (update.status === "done" && task.requiresUserReview) {
-        const importantTypes = ["prd","technical_spec","design_doc","project_brief","proposal","budget_proposal","architecture_decision","contract","sop"];
+        const importantTypes = IMPORTANT_DOC_TYPES;
         const placeholders = importantTypes.map(() => "?").join(", ");
         const docs = db.queryAll<{ id: string; type: string; title: string }>(
           `select id, type, title from documents where company_id = ? and type in (${placeholders})
diff --git a/src/shared/document-categories.ts b/src/shared/document-categories.ts
new file mode 100644
index 00000000..8fb83230
--- /dev/null
+++ b/src/shared/document-categories.ts
@@ -0,0 +1,22 @@
+/**
+ * Document type categories shared between db, route handlers, and clients.
+ *
+ * IMPORTANT_DOC_TYPES are the document types that trigger deliverable-review
+ * approvals (PRDs, specs, design docs, contracts, etc.). The ordering matters
+ * for some lookup queries; keep this in sync with database/documents.ts.
+ */
+export const IMPORTANT_DOC_TYPES = [
+  "prd",
+  "technical_spec",
+  "design_doc",
+  "project_brief",
+  "proposal",
+  "budget_proposal",
+  "architecture_decision",
+  "contract",
+  "sop",
+] as const;
+
+export type ImportantDocType = (typeof IMPORTANT_DOC_TYPES)[number];
+
+export const IMPORTANT_DOC_TYPE_SET: ReadonlySet<string> = new Set(IMPORTANT_DOC_TYPES);