diff --git a/changelog.d/features/6752-plugins-marketplace-install-api.md b/changelog.d/features/6752-plugins-marketplace-install-api.md
new file mode 100644
index 0000000000..4b53508688
--- /dev/null
+++ b/changelog.d/features/6752-plugins-marketplace-install-api.md
@@ -0,0 +1 @@
+- **feat(api):** add plugins marketplace install endpoint with checksum verification ([#6752](https://github.com/diegosouzapw/OmniRoute/issues/6752))
diff --git a/src/app/api/plugins/marketplace/install/route.ts b/src/app/api/plugins/marketplace/install/route.ts
new file mode 100644
index 0000000000..f2c1b24e5b
--- /dev/null
+++ b/src/app/api/plugins/marketplace/install/route.ts
@@ -0,0 +1,36 @@
+import { NextRequest, NextResponse } from "next/server";
+import { CORS_HEADERS, handleCorsOptions } from "@/shared/utils/cors";
+import { buildErrorBody } from "@omniroute/open-sse/utils/error";
+import { installMarketplacePlugin } from "@/lib/plugins/marketplace";
+import { requireManagementAuth } from "@/lib/api/requireManagementAuth";
+
+export async function OPTIONS() {
+  return handleCorsOptions();
+}
+
+/**
+ * POST /api/plugins/marketplace/install — Install a plugin from marketplace by name
+ */
+export async function POST(request: NextRequest) {
+  const authError = await requireManagementAuth(request);
+  if (authError) return authError;
+  try {
+    const body = await request.json();
+    const { name } = body as { name?: string };
+    if (!name || typeof name !== "string") {
+      return NextResponse.json(buildErrorBody(400, "Missing or invalid 'name' field"), {
+        status: 400,
+        headers: CORS_HEADERS,
+      });
+    }
+    const result = await installMarketplacePlugin(name);
+    return NextResponse.json(result, { status: 201, headers: CORS_HEADERS });
+  } catch (err: unknown) {
+    const msg = err instanceof Error ? err.message : "Failed to install marketplace plugin";
+    console.error("[plugins/marketplace] Install error:", msg);
+    return NextResponse.json(buildErrorBody(400, msg), {
+      status: 400,
+      headers: CORS_HEADERS,
+    });
+  }
+}
diff --git a/src/lib/plugins/marketplace.ts b/src/lib/plugins/marketplace.ts
index beca410668..39d0f7b1e7 100644
--- a/src/lib/plugins/marketplace.ts
+++ b/src/lib/plugins/marketplace.ts
@@ -2,6 +2,11 @@ import { getSettings } from "../db/settings";
 import dns from "node:dns/promises";
 import { isPrivateHost } from "@/shared/network/outboundUrlGuard";
 import { safeOutboundFetch } from "@/shared/network/safeOutboundFetch";
+import { pluginManager } from "./manager";
+import { createHash } from "node:crypto";
+import { mkdtemp, writeFile, rm } from "node:fs/promises";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
 /**
  * Plugin Marketplace — browse, search, install plugins from a registry.
  *
@@ -69,6 +74,7 @@ export interface MarketplaceEntry {
   author: string;
   license: string;
   downloadUrl: string;
+  checksum?: string; // SHA-256 hex (optional — verified when present)
   repository?: string;
   tags: string[];
   downloads: number;
@@ -200,3 +206,48 @@ export async function getMarketplaceEntry(name: string): Promise<MarketplaceEntr
 export function isMarketplaceAvailable(): boolean {
   return true; // Always available (falls back to seed)
 }
+
+/**
+ * Install a plugin from the marketplace by name.
+ * Downloads the plugin archive, verifies checksum if present, and installs via PluginManager.
+ */
+export async function installMarketplacePlugin(name: string): Promise<{ name: string; version: string }> {
+  const plugins = await listMarketplacePlugins();
+  const entry = plugins.find((p) => p.name === name);
+  if (!entry) {
+    throw new Error(`Plugin '${name}' not found in marketplace`);
+  }
+
+  // Create temp dir for download
+  const tmpDir = await mkdtemp(join(tmpdir(), "plugin-mp-"));
+  const tmpFile = join(tmpDir, "plugin.tar.gz");
+
+  try {
+    // Download the plugin archive
+    const response = await safeOutboundFetch(entry.downloadUrl, { guard: "public-only" });
+    if (!response.ok) {
+      throw new Error(`Failed to download plugin '${name}': ${response.status}`);
+    }
+    const buffer = Buffer.from(await response.arrayBuffer());
+
+    // Verify SHA-256 checksum if provided
+    if (entry.checksum) {
+      const actual = createHash("sha256").update(buffer).digest("hex");
+      if (actual !== entry.checksum) {
+        throw new Error(
+          `Checksum mismatch for plugin '${name}': expected ${entry.checksum}, got ${actual}`
+        );
+      }
+    }
+
+    // Write to temp file
+    await writeFile(tmpFile, buffer);
+
+    // Delegate to pluginManager.install
+    const result = await pluginManager.install(tmpDir);
+    return { name: result.name, version: result.version };
+  } finally {
+    // Cleanup temp dir
+    await rm(tmpDir, { recursive: true, force: true }).catch(() => {});
+  }
+}
diff --git a/tests/unit/plugins-marketplace-install.test.ts b/tests/unit/plugins-marketplace-install.test.ts
new file mode 100644
index 0000000000..3e35781841
--- /dev/null
+++ b/tests/unit/plugins-marketplace-install.test.ts
@@ -0,0 +1,38 @@
+import { describe, it } from "node:test";
+import { ok, equal } from "node:assert/strict";
+
+describe("Plugins marketplace install (#6752)", () => {
+  it("MarketplaceEntry supports optional checksum field", async () => {
+    const { searchMarketplace } = await import("@/lib/plugins/marketplace");
+    const results = await searchMarketplace("prompt");
+    ok(Array.isArray(results));
+    for (const entry of results) {
+      ok(typeof entry.name === "string");
+      ok(typeof entry.downloadUrl === "string");
+      // The checksum field exists in the type (may be undefined)
+      if (entry.checksum !== undefined) {
+        ok(typeof entry.checksum === "string");
+      }
+    }
+  });
+
+  it("installMarketplacePlugin throws for unknown plugin", async () => {
+    const { installMarketplacePlugin } = await import("@/lib/plugins/marketplace");
+    try {
+      await installMarketplacePlugin("nonexistent-plugin");
+      ok(false, "should have thrown");
+    } catch (e: unknown) {
+      ok((e as Error).message.includes("not found"));
+    }
+  });
+
+  it("checksum verification logic works", async () => {
+    const crypto = await import("node:crypto");
+    const data = Buffer.from("test-plugin-data");
+    const hash = crypto.createHash("sha256").update(data).digest("hex");
+    const hash2 = crypto.createHash("sha256").update(data).digest("hex");
+    equal(hash, hash2, "same data should produce same hash");
+    const hash3 = crypto.createHash("sha256").update(Buffer.from("different-data")).digest("hex");
+    ok(hash !== hash3, "different data should produce different hash");
+  });
+});