fix(screenshots): restrict screenshot URLs to our own R2 bucket

app/api/posts/edit/[token]/route.test.ts

@@ -1,5 +1,5 @@
 import { NextRequest } from "next/server";
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 const from = vi.fn();
 
@@ -16,9 +16,52 @@ function createPatchRequest(body: unknown) {
 }
 
 describe("PATCH /api/posts/edit/[token]", () => {
+  const originalEnv = { ...process.env };
+
   beforeEach(() => {
     vi.resetModules();
     vi.clearAllMocks();
+    process.env.R2_PUBLIC_URL = "https://cdn.example.com";
+  });
+
+  afterEach(() => {
+    process.env = { ...originalEnv };
+  });
+
+  it("rejects a screenshot URL that isn't on our own R2 bucket", async () => {
+    from.mockImplementation((table: string) => {
+      if (table === "posts") {
+        return {
+          select: () => ({
+            eq: () => ({
+              maybeSingle: async () => ({
+                data: { id: "post-1" },
+                error: null,
+              }),
+            }),
+          }),
+        };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { PATCH } = await import("./route");
+    const response = await PATCH(
+      createPatchRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+        screenshotUrls: ["https://evil.example.com/pwned.png"],
+      }),
+      { params: { token: "token-123" } },
+    );
+
+    expect(response.status).toBe(400);
   });
 
   it("returns 404 for an invalid edit token", async () => {
@@ -120,6 +163,9 @@ describe("PATCH /api/posts/edit/[token]", () => {
         tags: ["hallucination"],
         isAnonymous: false,
         authorHandle: "ops-team",
+        screenshotUrls: [
+          "https://cdn.example.com/screenshots/8f14e45f-ceea-467e-b7d1-3cfa78f5c15e.png",
+        ],
       }),
       { params: { token: "token-123" } },
     );
@@ -131,4 +177,40 @@ describe("PATCH /api/posts/edit/[token]", () => {
       { post_id: "post-1", tag_id: "tag-1" },
     ]);
   });
+
+  it("rejects a well-formed R2 URL with a malformed object key", async () => {
+    from.mockImplementation((table: string) => {
+      if (table === "posts") {
+        return {
+          select: () => ({
+            eq: () => ({
+              maybeSingle: async () => ({
+                data: { id: "post-1" },
+                error: null,
+              }),
+            }),
+          }),
+        };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { PATCH } = await import("./route");
+    const response = await PATCH(
+      createPatchRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+        screenshotUrls: ["https://cdn.example.com/screenshots/not-a-uuid.png"],
+      }),
+      { params: { token: "token-123" } },
+    );
+
+    expect(response.status).toBe(400);
+  });
 });

app/api/posts/edit/[token]/route.ts

@@ -1,12 +1,11 @@
 import { createHash } from "crypto";
 import { NextRequest, NextResponse } from "next/server";
-import { z } from "zod";
 import { createSupabaseAdminClient } from "@/lib/supabase/admin";
-import { submitSchema } from "@/lib/schemas/submit";
+import { submitSchema, screenshotUrlsSchema } from "@/lib/schemas/submit";
 import { redactPii } from "@/lib/utils/pii";
 
 const editSchema = submitSchema.extend({
-  screenshotUrls: z.array(z.string().url()).max(5).optional(),
+  screenshotUrls: screenshotUrlsSchema,
 });
 
 interface EditablePostRow {

app/api/posts/route.test.ts

@@ -1,5 +1,5 @@
 import { NextRequest } from "next/server";
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 const sendEditTokenEmail = vi.fn();
 const hashIp = vi.fn(() => "hashed-ip");
@@ -42,9 +42,224 @@ function createRequest(body: unknown) {
 }
 
 describe("POST /api/posts", () => {
+  const originalEnv = { ...process.env };
+
   beforeEach(() => {
     vi.resetModules();
     vi.clearAllMocks();
+    process.env.R2_PUBLIC_URL = "https://cdn.example.com";
+  });
+
+  afterEach(() => {
+    process.env = { ...originalEnv };
+  });
+
+  it("rejects a screenshot URL that isn't on our own R2 bucket", async () => {
+    from.mockImplementation((table: string) => {
+      if (table === "agents") {
+        return {
+          select: () => ({
+            eq: () => ({
+              single: async () => ({ data: { id: "agent-1" }, error: null }),
+            }),
+          }),
+        };
+      }
+
+      if (table === "tags") {
+        return {
+          select: () => ({
+            in: async () => ({
+              data: [{ id: "tag-1", slug: "hallucination" }],
+              error: null,
+            }),
+          }),
+        };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { POST } = await import("./route");
+    const response = await POST(
+      createRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+        screenshotUrls: ["https://evil.example.com/pwned.png"],
+      }),
+    );
+
+    expect(response.status).toBe(400);
+  });
+
+  it("rejects a well-formed R2 URL with a malformed object key", async () => {
+    from.mockImplementation((table: string) => {
+      if (table === "agents") {
+        return {
+          select: () => ({
+            eq: () => ({
+              single: async () => ({ data: { id: "agent-1" }, error: null }),
+            }),
+          }),
+        };
+      }
+
+      if (table === "tags") {
+        return {
+          select: () => ({
+            in: async () => ({
+              data: [{ id: "tag-1", slug: "hallucination" }],
+              error: null,
+            }),
+          }),
+        };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { POST } = await import("./route");
+    const response = await POST(
+      createRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+        screenshotUrls: ["https://cdn.example.com/screenshots/not-a-uuid.png"],
+      }),
+    );
+
+    expect(response.status).toBe(400);
+  });
+
+  it("accepts a submission with a valid R2 screenshot URL", async () => {
+    const insertSpy = vi.fn().mockReturnValue({
+      select: () => ({
+        single: async () => ({ data: { id: "post-1" }, error: null }),
+      }),
+    });
+
+    from.mockImplementation((table: string) => {
+      if (table === "agents") {
+        return {
+          select: () => ({
+            eq: () => ({
+              single: async () => ({ data: { id: "agent-1" }, error: null }),
+            }),
+          }),
+        };
+      }
+
+      if (table === "tags") {
+        return {
+          select: () => ({
+            in: async () => ({
+              data: [{ id: "tag-1", slug: "hallucination" }],
+              error: null,
+            }),
+          }),
+        };
+      }
+
+      if (table === "posts") {
+        return { insert: insertSpy };
+      }
+
+      if (table === "post_tags") {
+        return { insert: vi.fn().mockResolvedValue({ error: null }) };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { POST } = await import("./route");
+    const response = await POST(
+      createRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+        screenshotUrls: [
+          "https://cdn.example.com/screenshots/8f14e45f-ceea-467e-b7d1-3cfa78f5c15e.png",
+        ],
+      }),
+    );
+
+    expect(response.status).toBe(201);
+    expect(insertSpy).toHaveBeenCalledWith(
+      expect.objectContaining({
+        screenshot_urls: [
+          "https://cdn.example.com/screenshots/8f14e45f-ceea-467e-b7d1-3cfa78f5c15e.png",
+        ],
+      }),
+    );
+  });
+
+  it("accepts a submission with no screenshots at all", async () => {
+    const insertSpy = vi.fn().mockReturnValue({
+      select: () => ({
+        single: async () => ({ data: { id: "post-1" }, error: null }),
+      }),
+    });
+
+    from.mockImplementation((table: string) => {
+      if (table === "agents") {
+        return {
+          select: () => ({
+            eq: () => ({
+              single: async () => ({ data: { id: "agent-1" }, error: null }),
+            }),
+          }),
+        };
+      }
+
+      if (table === "tags") {
+        return {
+          select: () => ({
+            in: async () => ({
+              data: [{ id: "tag-1", slug: "hallucination" }],
+              error: null,
+            }),
+          }),
+        };
+      }
+
+      if (table === "posts") {
+        return { insert: insertSpy };
+      }
+
+      if (table === "post_tags") {
+        return { insert: vi.fn().mockResolvedValue({ error: null }) };
+      }
+
+      throw new Error(`Unexpected table ${table}`);
+    });
+
+    const { POST } = await import("./route");
+    const response = await POST(
+      createRequest({
+        agentSlug: "claude",
+        title: "Agent deleted a customer record during a routine sync",
+        outcome:
+          "The assistant misunderstood the task, deleted a live customer record, and forced the team into a manual restore that took several hours to unwind safely.",
+        damageLevel: 3,
+        tags: ["hallucination"],
+        isAnonymous: true,
+      }),
+    );
+
+    expect(response.status).toBe(201);
   });
 
   it("rejects unknown tags instead of silently dropping them", async () => {

app/api/posts/route.ts

@@ -1,6 +1,5 @@
 import { NextRequest, NextResponse } from "next/server";
-import { z } from "zod";
-import { submitSchema } from "@/lib/schemas/submit";
+import { submitSchema, screenshotUrlsSchema } from "@/lib/schemas/submit";
 import { createSupabaseAdminClient } from "@/lib/supabase/admin";
 import { sendEditTokenEmail } from "@/lib/resend/send";
 import { hashIp, getClientIp } from "@/lib/utils/hash";
@@ -13,7 +12,7 @@ const WINDOW_SECONDS = 60 * 60;
 const MAX_SUBMISSIONS = 3;
 
 const bodySchema = submitSchema.extend({
-  screenshotUrls: z.array(z.string().url()).max(5).optional(),
+  screenshotUrls: screenshotUrlsSchema,
 });
 
 export async function POST(req: NextRequest) {