feat: file blocks

Moderators block a file network-wide by its sha256, from a product's files or the console's new Blocks tab, which
first shows the products using it. Blocking removes those products (their creators are told and may appeal), puts
a `block` change in the changes feed of every catalog hosting it, and refuses uploads with it; moderators see who
tried. Unblocking lets it in again; the products it removed stay removed until restored.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/api/src/app.ts

@@ -26,7 +26,8 @@ import { ImvuClient, ImvuUnavailable, NoSuchImvuUser } from "./imvu";
 import { Realtime } from "./realtime";
 import { isAdultRoom, Rooms } from "./rooms";
 import { Signer } from "./keys";
-import { availableTo, ProductError, Products, type EditRights, type ProductViewer } from "./products";
+import { Blocks, isSha256 } from "./blocks";
+import { availableTo, BlockedUpload, ProductError, Products, type EditRights, type ProductViewer } from "./products";
 import {
   chatId,
   HostedError,
@@ -182,6 +183,7 @@ export function createApp({
     });
   const limiter = new Limiter();
   const cases = new Cases(db, perms);
+  const blocks = new Blocks(db);
   const notifications = new Notifications(db, (userId, message) => realtime.notify(userId, message));
 
   /** Tells a product's creator that someone else changed it. */
@@ -407,7 +409,15 @@ export function createApp({
     url: `${(webURL ?? "").replace(/\/+$/, "")}/catalogs/${i.catalogId}?invite=${i.code}`,
   });
 
-  type ConsoleSection = "overview" | "products" | "catalogs" | "cases" | "people" | "audit" | "settings";
+  type ConsoleSection = "overview" | "products" | "catalogs" | "cases" | "people" | "blocks" | "audit" | "settings";
+
+  const blockParam = t.Object({ sha256: t.String({ pattern: "^[0-9a-f]{64}$" }) });
+  const blockView = (b: { block: typeof schema.fileBlock.$inferSelect; by: string | null }) => ({
+    sha256: b.block.sha256,
+    reason: b.block.reason,
+    by: b.by,
+    at: b.block.createdAt.toISOString(),
+  });
 
   const caseParam = t.Object({ id: t.Numeric({ minimum: 1, multipleOf: 1 }) });
 
@@ -1719,7 +1729,16 @@ export function createApp({
       async ({ request, body, set }) => {
         const c = await products.catalogFor(request.headers.get("authorization"));
         if (!c) throw new Problem(401, "forbidden", "Not an approved catalog.");
-        const r = await productCall(() => products.registerRevision(c, body));
+        const r = await productCall(async () => {
+          try {
+            return await products.registerRevision(c, body);
+          } catch (e) {
+            // Someone tried a blocked file again: moderators see who, and from which catalog.
+            if (e instanceof BlockedUpload)
+              await audited(e.personId, "file.blocked_upload", c.id, { files: e.files }, { catalog: c.id, person: e.personId });
+            throw e;
+          }
+        });
         set.status = 201;
         return r;
       },
@@ -1976,6 +1995,54 @@ export function createApp({
       },
       { moderator: true, params: productParam, body: t.Object({ reason: t.String({ minLength: 1, maxLength: 500 }) }) },
     )
+    // File blocks: moderation blocks a file network-wide (docs/products.md).
+    .get(
+      "/blocks",
+      async ({ me, query }) => {
+        await need(me, "product:remove", hubScope);
+        const limit = 50;
+        const rows = await blocks.list({ before: query.before ? new Date(query.before) : undefined, limit });
+        return { blocks: rows.map(blockView), before: rows.length === limit ? rows.at(-1)!.block.createdAt.toISOString() : null };
+      },
+      { signedIn: true, query: t.Object({ before: t.Optional(t.String({ format: "date-time" })) }) },
+    )
+    // A file's block, if any, and the products using it (what blocking it removes).
+    .get(
+      "/blocks/:sha256",
+      async ({ me, params }) => {
+        await need(me, "product:remove", hubScope);
+        const b = await blocks.get(params.sha256);
+        return { block: b ? blockView(b) : null, products: await blocks.usedBy(params.sha256) };
+      },
+      { signedIn: true, params: blockParam },
+    )
+    .put(
+      "/blocks/:sha256",
+      async ({ me, params, body }) => {
+        await need(me, "product:remove", hubScope);
+        const reason = body.reason.trim();
+        if (!reason || !isSha256(params.sha256)) throw new Problem(400, "invalid", "Give a reason.");
+        const removed = await productCall(() => blocks.block(params.sha256, reason, me.id));
+        await audited(me.id, "file.block", params.sha256, { reason, removed: removed.map((p) => p.id) });
+        for (const p of removed) {
+          await audited(me.id, "product.remove", p.id, { reason, file: params.sha256 }, { product: p.id, person: p.creatorId });
+          await notifications.add(p.creatorId, "product_removed", { product: p.id, name: p.name, reason }, { product: p.id }, me.id);
+        }
+        return { removed: removed.map((p) => ({ id: p.id, name: p.name })) };
+      },
+      { signedIn: true, params: blockParam, body: t.Object({ reason: t.String({ maxLength: 500 }) }) },
+    )
+    .delete(
+      "/blocks/:sha256",
+      async ({ me, params, body, set }) => {
+        await need(me, "product:remove", hubScope);
+        await productCall(() => blocks.unblock(params.sha256));
+        const reason = body?.reason?.trim() ?? "";
+        await audited(me.id, "file.unblock", params.sha256, reason ? { reason } : {});
+        set.status = 204;
+      },
+      { signedIn: true, params: blockParam, body: t.Optional(t.Object({ reason: t.Optional(t.String({ maxLength: 500 })) })) },
+    )
     // Moderation restores a removed product (an upheld appeal, a mistake).
     .post(
       "/products/:id/unremove",
@@ -2458,6 +2525,7 @@ export function createApp({
         if (mod || scope.catalogs.length || scope.products.length || (await cases.list(me, { limit: 1 })).length)
           sections.push("cases");
         if (mod) sections.push("people");
+        if (await perms.can(me, "product:remove", hubScope)) sections.push("blocks");
         if (sections.length > 1 || scope.rooms.length) sections.push("audit");
         if (me.role === "admin") sections.push("settings");
         if (sections.length === 1)

apps/api/src/blocks.ts

@@ -0,0 +1,113 @@
+// File blocks (docs/products.md): moderation blocks a file network-wide by its sha256, so a removed product can't
+// come back under another name. Revisions with a blocked file can't be registered, products using it are removed,
+// and the catalogs hosting it are told to delete it. The routes in app.ts check permissions, audit and notify.
+import { and, desc, eq, inArray, isNull, lt, sql, schema, type Database } from "@t5de/db";
+import { ProductError } from "./products";
+
+const { catalogChange, fileBlock, hosting, product, productRevision, user } = schema;
+
+export const isSha256 = (s: string) => /^[0-9a-f]{64}$/.test(s);
+
+/** A product with a revision using a file. */
+export type FileUse = {
+  id: string;
+  name: string;
+  creatorId: string;
+  creatorUsername: string | null;
+  removed: boolean;
+  revisions: number[];
+};
+
+export class Blocks {
+  constructor(private db: Database) {}
+
+  async get(sha256: string) {
+    const [b] = await this.db
+      .select({ block: fileBlock, by: user.username })
+      .from(fileBlock)
+      .leftJoin(user, eq(user.id, fileBlock.byId))
+      .where(eq(fileBlock.sha256, sha256));
+    return b;
+  }
+
+  /** Which of these files are blocked. */
+  async blocked(sha256s: string[]): Promise<string[]> {
+    if (sha256s.length === 0) return [];
+    const rows = await this.db.select({ sha256: fileBlock.sha256 }).from(fileBlock).where(inArray(fileBlock.sha256, sha256s));
+    return rows.map((r) => r.sha256);
+  }
+
+  /** The products with a revision using a file (what blocking it would remove), newest first. */
+  async usedBy(sha256: string): Promise<FileUse[]> {
+    const rows = await this.db
+      .select({ p: product, creatorUsername: user.username, number: productRevision.number })
+      .from(productRevision)
+      .innerJoin(product, eq(product.id, productRevision.productId))
+      .leftJoin(user, eq(user.id, product.creatorId))
+      .where(sql`${productRevision.files} @> ${JSON.stringify([{ sha256 }])}::jsonb`)
+      .orderBy(desc(product.createdAt), productRevision.number);
+    const out = new Map<string, FileUse>();
+    for (const r of rows) {
+      if (r.p.deletedAt && !r.p.removedAt) continue; // deleted by its creator: nothing to remove
+      const u = out.get(r.p.id) ?? {
+        id: r.p.id,
+        name: r.p.name,
+        creatorId: r.p.creatorId,
+        creatorUsername: r.creatorUsername,
+        removed: r.p.removedAt !== null,
+        revisions: [],
+      };
+      u.revisions.push(r.number);
+      out.set(r.p.id, u);
+    }
+    return [...out.values()];
+  }
+
+  /**
+   * Blocks a file: removes the products using it (those not removed already, which are returned) and tells the
+   * catalogs hosting it to delete it (a `block` change).
+   */
+  async block(sha256: string, reason: string, byId: string): Promise<FileUse[]> {
+    if (!isSha256(sha256)) throw new ProductError(400, "invalid", "That isn't a file's sha256 (64 hex digits).");
+    const uses = await this.usedBy(sha256);
+    const ids = uses.map((u) => u.id);
+    const removed = uses.filter((u) => !u.removed);
+    await this.db.transaction(async (tx) => {
+      const [made] = await tx.insert(fileBlock).values({ sha256, reason, byId }).onConflictDoNothing().returning();
+      if (!made) throw new ProductError(409, "blocked", "That file is blocked already.");
+      if (removed.length)
+        await tx
+          .update(product)
+          .set({ removedAt: new Date(), removedReason: reason })
+          .where(and(inArray(product.id, removed.map((u) => u.id)), isNull(product.removedAt)));
+      if (ids.length) {
+        const hosts = await tx
+          .selectDistinct({ catalogId: hosting.catalogId })
+          .from(hosting)
+          .innerJoin(productRevision, and(eq(productRevision.productId, hosting.productId), eq(productRevision.number, hosting.number)))
+          .where(and(inArray(hosting.productId, ids), sql`${productRevision.files} @> ${JSON.stringify([{ sha256 }])}::jsonb`));
+        if (hosts.length) await tx.insert(catalogChange).values(hosts.map((h) => ({ catalogId: h.catalogId, data: { type: "block", sha256 } })));
+      }
+    });
+    return removed;
+  }
+
+  /** Unblocks a file. Products it removed stay removed (moderators restore them one by one); catalogs aren't told,
+   * since they deleted the file and get it again only with a new upload. */
+  async unblock(sha256: string) {
+    const [gone] = await this.db.delete(fileBlock).where(eq(fileBlock.sha256, sha256)).returning();
+    if (!gone) throw new ProductError(404, "not_found", "That file isn't blocked.");
+    return gone;
+  }
+
+  /** Blocks, newest first. */
+  async list(opts: { before?: Date; limit?: number } = {}) {
+    return this.db
+      .select({ block: fileBlock, by: user.username })
+      .from(fileBlock)
+      .leftJoin(user, eq(user.id, fileBlock.byId))
+      .where(opts.before ? lt(fileBlock.createdAt, opts.before) : undefined)
+      .orderBy(desc(fileBlock.createdAt))
+      .limit(opts.limit ?? 50);
+  }
+}

apps/api/src/products.ts

@@ -20,7 +20,7 @@ import { cleanHTML, maxDescription } from "./html";
 import type { ImvuClient } from "./imvu";
 import type { Signer } from "./keys";
 
-const { catalog, catalogChange, catalogMember, product, productInfoChange, productRevision, hosting, library, roleAssignment, user } =
+const { catalog, catalogChange, catalogMember, fileBlock, product, productInfoChange, productRevision, hosting, library, roleAssignment, user } =
   schema;
 
 export type Catalog = typeof catalog.$inferSelect;
@@ -63,6 +63,17 @@ export class ProductError extends Error {
   }
 }
 
+/** An upload with a blocked file (docs/products.md): refused, and the route audits who tried. */
+export class BlockedUpload extends ProductError {
+  constructor(
+    readonly personId: string,
+    readonly catalogId: string,
+    readonly files: FileEntry[],
+  ) {
+    super(409, "blocked", "This upload has a file T5DE blocks.");
+  }
+}
+
 const base32 = "abcdefghijklmnopqrstuvwxyz234567";
 export const newProductID = () =>
   [...crypto.getRandomValues(new Uint8Array(10))].map((b) => base32[b & 31]).join("");
@@ -260,6 +271,15 @@ export class Products {
     const parent = Number.isSafeInteger(body.parent) && body.parent > 0 ? body.parent : 0;
     const notes = (typeof body.notes === "string" ? body.notes.trim() : "").slice(0, 2000);
     const personId = claims.sub;
+    const blocked = new Set(
+      (
+        await this.db
+          .select({ sha256: fileBlock.sha256 })
+          .from(fileBlock)
+          .where(inArray(fileBlock.sha256, [...new Set(files.map((f) => f.sha256))]))
+      ).map((b) => b.sha256),
+    );
+    if (blocked.size) throw new BlockedUpload(personId, c.id, files.filter((f) => blocked.has(f.sha256)));
 
     const made = await this.db.transaction(async (tx) => {
       let p: Product;

apps/api/test/blocks.test.ts

@@ -0,0 +1,203 @@
+// File blocks (docs/products.md): moderation blocks a file network-wide; products using it are removed, catalogs told
+// to delete it, and uploads with it refused.
+import { afterAll, beforeAll, expect, test } from "bun:test";
+import { openDatabase, type Database } from "@t5de/db";
+import { createApp } from "../src/app";
+import { createAuth } from "../src/auth";
+import { ImvuClient, type ImvuUser } from "../src/imvu";
+
+const webURL = "http://web.test";
+const apiURL = "http://api.test";
+const accounts = new Map<number, ImvuUser>();
+const fakeIMVU: typeof fetch = (async (input: RequestInfo | URL) => {
+  const url = new URL(String(input));
+  if (url.pathname.startsWith("/product/")) return Response.json({ status: "failure" }, { status: 404 });
+  const u = [...accounts.values()].find(
+    (u) => url.pathname === `/user/user-${u.id}` || url.searchParams.get("username")?.toLowerCase() === u.username.toLowerCase(),
+  );
+  return Response.json({
+    denormalized: u
+      ? { [`https://api.imvu.com/user/user-${u.id}`]: { data: { legacy_cid: u.id, username: u.username, tagline: u.tagline, is_ageverified: u.ageVerified, is_ap: u.accessPass } } }
+      : {},
+  });
+}) as typeof fetch;
+
+// Catalog addresses that answer /health (for address changes).
+const healthy = new Set<string>(["https://moved.example.test"]);
+
+let db: Database;
+let close: () => Promise<void>;
+let base: string;
+let stop: () => void;
+
+beforeAll(async () => {
+  ({ db, close } = await openDatabase("memory"));
+  const auth = createAuth(db, { apiURL, webURL, secret: "test-secret-test-secret-test-secret-1234", rateLimit: false });
+  const hub = createApp({
+    db,
+    auth,
+    imvu: new ImvuClient("http://imvu.test", fakeIMVU),
+    apiURL,
+    webURL,
+    catalogHealthy: async (url) => healthy.has(url),
+  });
+  hub.app.listen({ port: 0, hostname: "127.0.0.1" });
+  const server = hub.app.server as unknown as { port: number; stop: () => void };
+  stop = () => server.stop();
+  base = `http://127.0.0.1:${server.port}`;
+});
+
+afterAll(async () => {
+  stop();
+  await close();
+});
+
+type Person = { cookie: string; name: string };
+async function call(p: Person | undefined, method: string, path: string, body?: unknown, headers: Record<string, string> = {}) {
+  const res = await fetch(base + path, {
+    method,
+    headers: { Origin: webURL, ...(body !== undefined ? { "Content-Type": "application/json" } : {}), ...(p ? { Cookie: p.cookie } : {}), ...headers },
+    body: body !== undefined ? JSON.stringify(body) : undefined,
+  });
+  const text = await res.text();
+  let json: any;
+  try {
+    json = JSON.parse(text);
+  } catch {
+    json = text;
+  }
+  return { status: res.status, json };
+}
+
+async function person(name: string): Promise<Person> {
+  const res = await fetch(base + "/api/auth/sign-up/email", {
+    method: "POST",
+    headers: { Origin: webURL, "Content-Type": "application/json" },
+    body: JSON.stringify({ email: `${name}@example.test`, password: "a long password", name, username: name }),
+  });
+  return { cookie: res.headers.getSetCookie().map((c) => c.split(";")[0]).join("; "), name };
+}
+
+const file = (name: string, n: number) => ({ name, sha256: n.toString(16).padStart(64, "0"), size: 100 * n });
+
+/** A person's catalog, registered and approved; its key's Authorization header. */
+async function catalogOf(owner: Person, admin: Person, name: string, membership = "open") {
+  const reg = await call(owner, "POST", "/api/v1/catalogs", {
+    name,
+    url: `https://${name.toLowerCase().replace(/\W/g, "")}.example.test`,
+    contact: "[email protected]",
+    visibility: "public",
+    membership,
+  });
+  expect(reg.status).toBe(201);
+  const id = reg.json.catalog.id as string;
+  expect((await call(admin, "POST", `/api/v1/console/catalogs/${id}/approve`)).status).toBe(200);
+  return { id, auth: { Authorization: `Catalog ${id}:${reg.json.key}` } };
+}
+
+/** A product uploaded by a person to a catalog; its ID. */
+async function upload(maker: Person, c: { id: string; auth: Record<string, string> }, name: string, n: number, rating = "general") {
+  const tok = await call(maker, "POST", "/api/v1/products/upload", { catalog: c.id });
+  expect(tok.status).toBe(200);
+  const r = await call(
+    undefined,
+    "POST",
+    "/api/v1/catalog/revisions",
+    { uploadToken: tok.json.token, files: [file("index.xml", n)], rating, parent: 0, name, notes: "" },
+    c.auth,
+  );
+  expect(r.status).toBe(201);
+  expect((await call(maker, "POST", `/api/v1/products/${r.json.product}/publish`)).status).toBe(200);
+  return r.json.product as string;
+}
+
+
+/** A revision with these files, by a person, to a catalog: the answer. */
+async function uploadFiles(maker: Person, c: { id: string; auth: Record<string, string> }, name: string, files: unknown[]) {
+  const tok = await call(maker, "POST", "/api/v1/products/upload", { catalog: c.id });
+  return call(undefined, "POST", "/api/v1/catalog/revisions", { uploadToken: tok.json.token, files, rating: "general", parent: 0, name, notes: "" }, c.auth);
+}
+
+let admin: Person;
+let mod: Person;
+
+test("the first account is the admin; a moderator", async () => {
+  admin = await person("admin1");
+  mod = await person("warden");
+  const id = (await call(mod, "GET", "/api/v1/me")).json.person.id;
+  expect((await call(admin, "POST", `/api/v1/console/people/${id}/role`, { role: "moderator" })).status).toBe(200);
+});
+
+test("blocking a file removes the products using it, tells their catalogs, and refuses it in uploads", async () => {
+  const owner = await person("shelfowner");
+  const maker = await person("maker");
+  const copier = await person("copier");
+  const c = await catalogOf(owner, admin, "Block Shelf");
+  const other = await catalogOf(copier, admin, "Copy Shelf");
+  const logo = file("logo.png", 2).sha256;
+
+  const tee = await upload(maker, c, "Logo Tee", 1);
+  const second = await call(maker, "POST", "/api/v1/products/upload", { catalog: c.id, product: tee });
+  expect(
+    (await call(undefined, "POST", "/api/v1/catalog/revisions", { uploadToken: second.json.token, files: [file("index.xml", 1), file("logo.png", 2)], rating: "general", parent: 0, name: "", notes: "Added the logo" }, c.auth)).status,
+  ).toBe(201);
+  const copy = (await uploadFiles(copier, other, "Copy Tee", [file("index.xml", 5), file("logo.png", 2)])).json.product as string;
+  const plain = await upload(maker, c, "Plain Tee", 3);
+
+  // Only those who can remove products hub-wide.
+  for (const p of [owner, maker]) {
+    expect((await call(p, "GET", "/api/v1/blocks")).status).toBe(403);
+    expect((await call(p, "GET", `/api/v1/blocks/${logo}`)).status).toBe(403);
+    expect((await call(p, "PUT", `/api/v1/blocks/${logo}`, { reason: "x" })).status).toBe(403);
+  }
+  expect((await call(owner, "GET", "/api/v1/console")).json.sections).not.toContain("blocks");
+  expect((await call(mod, "GET", "/api/v1/console")).json.sections).toContain("blocks");
+  expect((await call(mod, "GET", "/api/v1/blocks/not-a-hash")).status).toBe(400);
+
+  // What blocking it would remove.
+  const preview = (await call(mod, "GET", `/api/v1/blocks/${logo}`)).json;
+  expect(preview.block).toBeNull();
+  expect(preview.products.map((p: any) => [p.name, p.creatorUsername, p.revisions, p.removed]).sort()).toEqual([
+    ["Copy Tee", "copier", [1], false],
+    ["Logo Tee", "maker", [2], false],
+  ]);
+
+  const blocked = await call(mod, "PUT", `/api/v1/blocks/${logo}`, { reason: "Trademarked logo" });
+  expect(blocked.status).toBe(200);
+  expect(blocked.json.removed.map((p: any) => p.id).sort()).toEqual([copy, tee].sort());
+  expect((await call(mod, "PUT", `/api/v1/blocks/${logo}`, { reason: "Again" })).json.error).toBe("blocked");
+  expect((await call(undefined, "GET", `/api/v1/products/${tee}`)).status).toBe(410);
+  expect((await call(undefined, "GET", `/api/v1/products/${copy}`)).status).toBe(410);
+  expect((await call(undefined, "GET", `/api/v1/products/${plain}`)).status).toBe(200);
+  expect((await call(mod, "GET", `/api/v1/blocks/${logo}`)).json.block).toMatchObject({ sha256: logo, reason: "Trademarked logo", by: "warden" });
+  expect((await call(mod, "GET", "/api/v1/blocks")).json.blocks.map((b: any) => b.sha256)).toEqual([logo]);
+
+  // Each catalog that hosts it is told to delete it.
+  for (const k of [c, other]) {
+    const feed = (await call(undefined, "GET", "/api/v1/catalog/changes", undefined, k.auth)).json.changes;
+    expect(feed.filter((x: any) => x.type === "block")).toEqual([{ type: "block", sha256: logo }]);
+  }
+
+  // Creators are told, and may appeal the removal.
+  const told = (await call(maker, "GET", "/api/v1/notifications")).json.notifications[0];
+  expect(told).toMatchObject({ type: "product_removed", data: { product: tee, reason: "Trademarked logo" } });
+  const removal = (await call(maker, "GET", `/api/v1/console/audit?action=product.remove`)).json.entries[0];
+  expect(removal).toMatchObject({ target: tee, appealable: true, detail: { file: logo } });
+
+  // Uploads with it are refused, and moderators see who tried.
+  const again = await uploadFiles(copier, other, "Copy Tee 2", [file("index.xml", 6), file("logo2.png", 2)]);
+  expect(again.status).toBe(409);
+  expect(again.json.error).toBe("blocked");
+  const tried = (await call(mod, "GET", "/api/v1/console/audit?action=file.blocked_upload")).json.entries[0];
+  expect(tried).toMatchObject({ actor: "copier", tags: { catalog: other.id }, detail: { files: [{ name: "logo2.png", sha256: logo }] } });
+
+  // Unblocking lets it in again; the products it removed stay removed until restored.
+  expect((await call(owner, "DELETE", `/api/v1/blocks/${logo}`)).status).toBe(403);
+  expect((await call(mod, "DELETE", `/api/v1/blocks/${logo}`, { reason: "Licensed after all" })).status).toBe(204);
+  expect((await call(mod, "DELETE", `/api/v1/blocks/${logo}`)).status).toBe(404);
+  expect((await uploadFiles(copier, other, "Copy Tee 2", [file("index.xml", 6), file("logo2.png", 2)])).status).toBe(201);
+  expect((await call(undefined, "GET", `/api/v1/products/${tee}`)).status).toBe(410);
+  expect((await call(mod, "POST", `/api/v1/products/${tee}/unremove`, { reason: "Licensed" })).status).toBe(200);
+  expect((await call(undefined, "GET", `/api/v1/products/${tee}`)).status).toBe(200);
+  expect((await call(mod, "GET", "/api/v1/console/audit?action=file.unblock")).json.entries[0]).toMatchObject({ target: logo, detail: { reason: "Licensed after all" } });
+});

apps/api/test/catalogs.test.ts

@@ -300,7 +300,7 @@ test("the console is for everyone who controls something; its audit log shows on
   expect(ownerConsole.sections).toEqual(["overview", "catalogs", "cases", "audit"]);
   expect(ownerConsole.moderation).toBeNull();
   expect((await call(maker, "GET", "/api/v1/console")).json.sections).toEqual(["overview", "products", "cases", "audit"]);
-  expect((await call(admin, "GET", "/api/v1/console")).json.sections).toEqual(["overview", "products", "catalogs", "cases", "people", "audit", "settings"]);
+  expect((await call(admin, "GET", "/api/v1/console")).json.sections).toEqual(["overview", "products", "catalogs", "cases", "people", "blocks", "audit", "settings"]);
 
   // The owner sees their catalog's entries, not the other catalog's; the maker sees their product's.
   const ownerLog = (await call(owner, "GET", "/api/v1/console/audit")).json.entries;

apps/web/app/console/audit-table.tsx

@@ -60,7 +60,14 @@ export function AuditTable({ entries, empty = "Nothing yet." }: { entries: Audit
                   </span>
                 );
               })}
-              {Object.keys(e.tags).length === 0 && e.target}
+              {Object.keys(e.tags).length === 0 &&
+                (e.action.startsWith("file.") && /^[0-9a-f]{64}$/.test(e.target) ? (
+                  <Link href={`/console/blocks/${e.target}`} className="font-mono text-xs underline-offset-4 hover:underline">
+                    file {e.target.slice(0, 12)}…
+                  </Link>
+                ) : (
+                  e.target
+                ))}
             </TableCell>
             <TableCell className="text-xs whitespace-normal text-muted-foreground">
               {detailText(e.detail)}

apps/web/app/console/blocks/[sha256]/page.tsx

@@ -0,0 +1,106 @@
+import type { Metadata } from "next";
+import Link from "next/link";
+import { notFound } from "next/navigation";
+import { ActionForm, SubmitButton } from "@/components/forms";
+import { PageHeader, Tag } from "@/components/status";
+import { DateTime } from "@/components/time";
+import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
+import { Input } from "@/components/ui/input";
+import { api, unwrap } from "@/lib/api";
+import { ConsoleNav, requireConsole } from "../../console-nav";
+import { blockFile, unblockFile } from "../actions";
+
+export const metadata: Metadata = { title: "Block" };
+
+/** A file: whether it's blocked, the products using it, and blocking or unblocking it. */
+export default async function BlockPage({ params }: { params: Promise<{ sha256: string }> }) {
+  const { sha256 } = await params;
+  if (!/^[0-9a-f]{64}$/.test(sha256)) notFound();
+  const { console: c } = await requireConsole(`/console/blocks/${sha256}`);
+  if (!c.sections.includes("blocks")) notFound();
+  const { block, products } = unwrap(await api.blocks({ sha256 }).get());
+  const live = products.filter((p) => !p.removed);
+  const removeCount = live.length === 1 ? "1 product" : `${live.length} products`;
+
+  return (
+    <>
+      <PageHeader title="File">
+        <span className="font-mono text-xs break-all">{sha256}</span>
+      </PageHeader>
+      <ConsoleNav />
+      <div className="space-y-6">
+        <Card>
+          <CardHeader>
+            <CardTitle>{block ? "Blocked" : "Not Blocked"}</CardTitle>
+            <CardDescription>
+              {block ? (
+                <>
+                  By {block.by ?? "a former moderator"}, <DateTime iso={block.at} />: {block.reason}
+                </>
+              ) : (
+                "Blocking it removes the products below, tells their catalogs to delete it, and refuses uploads with it."
+              )}
+            </CardDescription>
+          </CardHeader>
+          <CardContent>
+            {block ? (
+              <ActionForm action={unblockFile} fields={{ sha256 }}>
+                <div className="flex flex-wrap gap-2">
+                  <Input name="reason" maxLength={500} placeholder="Reason" aria-label="Reason" className="max-w-sm" />
+                  <SubmitButton
+                    variant="outline"
+                    pendingLabel="Unblocking…"
+                    confirm="Unblock this file? The products it removed stay removed until restored."
+                  >
+                    Unblock
+                  </SubmitButton>
+                </div>
+              </ActionForm>
+            ) : (
+              <ActionForm action={blockFile} fields={{ sha256 }}>
+                <div className="flex flex-wrap gap-2">
+                  <Input name="reason" required maxLength={500} placeholder="Reason (creators see it)" aria-label="Reason" className="max-w-sm" />
+                  <SubmitButton
+                    variant="destructive"
+                    pendingLabel="Blocking…"
+                    confirm={live.length ? `Block this file and remove ${removeCount}?` : "Block this file?"}
+                  >
+                    {live.length ? `Block and remove ${removeCount}` : "Block"}
+                  </SubmitButton>
+                </div>
+              </ActionForm>
+            )}
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <CardTitle>Used By</CardTitle>
+            <CardDescription>Products with a revision that has this file.</CardDescription>
+          </CardHeader>
+          <CardContent>
+            {products.length === 0 ? (
+              <p className="text-sm text-muted-foreground">No product uses it.</p>
+            ) : (
+              <ul className="divide-y">
+                {products.map((p) => (
+                  <li key={p.id} className="flex flex-wrap items-center gap-x-3 gap-y-1 py-3 first:pt-0 last:pb-0">
+                    <Link
+                      href={p.removed ? `/console/products?q=${encodeURIComponent(p.name)}&status=removed&all=1` : `/products/${p.id}`}
+                      className="font-medium underline-offset-4 hover:underline"
+                    >
+                      {p.name}
+                    </Link>
+                    <span className="text-sm text-muted-foreground">
+                      by {p.creatorUsername ?? "someone"} · {p.revisions.length === 1 ? "revision" : "revisions"} {p.revisions.join(", ")}
+                    </span>
+                    {p.removed && <Tag tone="danger">removed</Tag>}
+                  </li>
+                ))}
+              </ul>
+            )}
+          </CardContent>
+        </Card>
+      </div>
+    </>
+  );
+}

apps/web/app/console/blocks/actions.ts

@@ -0,0 +1,31 @@
+"use server";
+// File blocks, from the console.
+import { revalidatePath } from "next/cache";
+import { api, unwrap } from "@/lib/api";
+import { attempt, field, type ActionState } from "@/lib/actions";
+
+const done = (sha256: string) => {
+  revalidatePath("/console/blocks");
+  revalidatePath(`/console/blocks/${sha256}`);
+  revalidatePath("/console/products");
+};
+
+/** Blocks a file network-wide, removing the products using it. */
+export async function blockFile(_: ActionState, form: FormData): Promise<ActionState> {
+  const sha256 = field(form, "sha256");
+  return attempt(async () => {
+    const { removed } = unwrap(await api.blocks({ sha256 }).put({ reason: field(form, "reason") }));
+    done(sha256);
+    return removed.length ? `Blocked. Removed ${removed.length === 1 ? "1 product" : `${removed.length} products`}.` : "Blocked.";
+  });
+}
+
+/** Unblocks a file. The products it removed stay removed. */
+export async function unblockFile(_: ActionState, form: FormData): Promise<ActionState> {
+  const sha256 = field(form, "sha256");
+  return attempt(async () => {
+    unwrap(await api.blocks({ sha256 }).delete({ reason: field(form, "reason") }));
+    done(sha256);
+    return "Unblocked.";
+  });
+}

apps/web/app/console/blocks/page.tsx

@@ -0,0 +1,88 @@
+import type { Metadata } from "next";
+import Link from "next/link";
+import { notFound, redirect } from "next/navigation";
+import { PageHeader } from "@/components/status";
+import { DateTime } from "@/components/time";
+import { Button, buttonVariants } from "@/components/ui/button";
+import { Card, CardContent } from "@/components/ui/card";
+import { Input } from "@/components/ui/input";
+import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table";
+import { api, unwrap } from "@/lib/api";
+import { ConsoleNav, requireConsole } from "../console-nav";
+
+export const metadata: Metadata = { title: "Blocks" };
+
+export default async function BlocksPage({ searchParams }: { searchParams: Promise<Record<string, string | string[]>> }) {
+  const { console: c } = await requireConsole("/console/blocks");
+  if (!c.sections.includes("blocks")) notFound();
+  const params = await searchParams;
+  // Looking a file up goes to its page.
+  if (typeof params.sha256 === "string") {
+    const sha256 = params.sha256.trim().toLowerCase();
+    if (/^[0-9a-f]{64}$/.test(sha256)) redirect(`/console/blocks/${sha256}`);
+  }
+  const before = typeof params.before === "string" && !Number.isNaN(Date.parse(params.before)) ? params.before : undefined;
+  const data = unwrap(await api.blocks.get({ query: before ? { before } : {} }));
+
+  return (
+    <>
+      <PageHeader title="Blocks">Blocked files: uploads with them are refused, and catalogs delete them.</PageHeader>
+      <ConsoleNav />
+      <form action="/console/blocks" className="mb-6 flex flex-wrap gap-2">
+        <Input
+          name="sha256"
+          required
+          pattern="\s*[0-9a-fA-F]{64}\s*"
+          defaultValue={typeof params.sha256 === "string" ? params.sha256 : ""}
+          placeholder="A file's sha256"
+          aria-label="sha256"
+          className="max-w-xl font-mono"
+        />
+        <Button type="submit">Look up</Button>
+      </form>
+      <Card>
+        <CardContent>
+          {data.blocks.length === 0 ? (
+            <p className="text-sm text-muted-foreground">
+              Nothing blocked. Block a file from a product&apos;s files, or look it up above.
+            </p>
+          ) : (
+            <Table>
+              <TableHeader>
+                <TableRow>
+                  <TableHead>File</TableHead>
+                  <TableHead>Reason</TableHead>
+                  <TableHead>By</TableHead>
+                  <TableHead>When</TableHead>
+                </TableRow>
+              </TableHeader>
+              <TableBody>
+                {data.blocks.map((b) => (
+                  <TableRow key={b.sha256}>
+                    <TableCell className="font-mono text-xs">
+                      <Link href={`/console/blocks/${b.sha256}`} className="underline-offset-4 hover:underline">
+                        {b.sha256.slice(0, 16)}…
+                      </Link>
+                    </TableCell>
+                    <TableCell className="whitespace-normal">{b.reason}</TableCell>
+                    <TableCell className="text-muted-foreground">{b.by ?? ""}</TableCell>
+                    <TableCell className="text-muted-foreground">
+                      <DateTime iso={b.at} />
+                    </TableCell>
+                  </TableRow>
+                ))}
+              </TableBody>
+            </Table>
+          )}
+        </CardContent>
+      </Card>
+      {data.before && (
+        <div className="mt-4">
+          <Link href={`/console/blocks?before=${encodeURIComponent(data.before)}`} className={buttonVariants({ variant: "outline" })}>
+            Older
+          </Link>
+        </div>
+      )}
+    </>
+  );
+}

apps/web/app/console/console-nav.tsx

@@ -39,6 +39,7 @@ const tabs: { section: Section; href: string; label: string }[] = [
   { section: "catalogs", href: "/console/catalogs", label: "Catalogs" },
   { section: "cases", href: "/console/cases", label: "Cases" },
   { section: "people", href: "/console/people", label: "People" },
+  { section: "blocks", href: "/console/blocks", label: "Blocks" },
   { section: "audit", href: "/console/audit", label: "Audit" },
 ];
 

apps/web/app/products/[id]/page.tsx

@@ -189,6 +189,7 @@ export default async function ProductPage({ params }: { params: Promise<{ id: st
                 stayOn={stayOn}
                 using={using === r.number}
                 mine={mine}
+                canBlock={permissions.includes("product:remove")}
               />
             ))}
           </ul>
@@ -212,6 +213,7 @@ function RevisionRow({
   stayOn,
   using,
   mine,
+  canBlock,
 }: {
   id: string;
   revision: Revision;
@@ -220,6 +222,8 @@ function RevisionRow({
   stayOn: number | null;
   using: boolean;
   mine: boolean;
+  /** Moderators: each file links to blocking it. */
+  canBlock: boolean;
 }) {
   const facts = [
     formatSize(r.size),
@@ -247,6 +251,11 @@ function RevisionRow({
             <li key={f.name} className="flex gap-3">
               <span className="min-w-0 flex-1 truncate">{f.name}</span>
               <span className="text-muted-foreground tabular-nums">{formatSize(f.size)}</span>
+              {canBlock && (
+                <Link href={`/console/blocks/${f.sha256}`} className="text-muted-foreground underline-offset-4 hover:text-foreground hover:underline">
+                  Block
+                </Link>
+              )}
             </li>
           ))}
         </ul>