Vendor-neutral age verification, with IMVU as the first provider

Age checks are recorded in one table (age_check) by provider, method and result, never with documents or
birth dates; one rule decides whether an IMVU account counts as adult (its person's check, or its own).
Providers implement a small interface (start, webhook or browser completion, re-check) and are chosen by
configuration, so phone wallets and Didit can be added, or swapped, as adapters. IMVU's answer per account
is re-checked when it expires (about daily). Existing links' results move into the new table.

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

apps/api/src/app.ts

@@ -4,12 +4,14 @@
 import { Elysia, t } from "elysia";
 import { and, desc, eq, ilike, inArray, ne, or, sql, count, schema, type Database } from "@t5de/db";
 import type { Auth } from "./auth";
+import { AgeError, AgeService } from "./age";
+import { imvuAgeProvider, imvuResult } from "./age/imvu";
 import { ImvuClient, ImvuUnavailable, NoSuchImvuUser } from "./imvu";
 import { Realtime } from "./realtime";
 
 const { user, session, imvuLink, linkChallenge, audit } = schema;
 
-export type Deps = { db: Database; auth: Auth; imvu: ImvuClient; realtime?: Realtime };
+export type Deps = { db: Database; auth: Auth; imvu: ImvuClient; realtime?: Realtime; age?: AgeService };
 
 /** An error shown to the person: the website displays message as is. */
 export class Problem extends Error {
@@ -59,7 +61,8 @@ class Limiter {
   }
 }
 
-export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
+export function createApp({ db, auth, imvu, realtime: rt, age: ageService }: Deps) {
+  const age = ageService ?? new AgeService(db, [imvuAgeProvider(imvu)]);
   const realtime =
     rt ??
     new Realtime(async (imvuId) => {
@@ -79,22 +82,31 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
     banReason: p.banReason ?? "",
   });
 
-  const linkView = (l: Link) => {
-    const live = realtime.online().find((o) => o.imvuId === l.imvuId);
-    return {
-      imvuId: l.imvuId,
-      username: l.username,
-      linkedAt: l.linkedAt.toISOString(),
-      ageVerified: l.ageVerified,
-      accessPass: l.accessPass,
-      adult: l.ageVerified || l.accessPass,
-      checkedAt: l.checkedAt.toISOString(),
-      showBadge: l.showBadge,
-      showPresence: l.showPresence,
-      online: live !== undefined,
-      outfit: live?.outfit ?? [],
-    };
+  /** Links as the website shows them: with live presence, and age by the one rule. */
+  const linkViews = async (userId: string, links: Link[]) => {
+    const ids = links.map((l) => l.imvuId);
+    const adult = await age.adultAccounts(userId, ids);
+    const imvuChecks = await age.accountChecks("imvu", ids);
+    const online = realtime.online();
+    return links.map((l) => {
+      const live = online.find((o) => o.imvuId === l.imvuId);
+      const check = imvuChecks.get(l.imvuId);
+      return {
+        imvuId: l.imvuId,
+        username: l.username,
+        linkedAt: l.linkedAt.toISOString(),
+        ageVerified: check?.method === "imvu_age_verified",
+        accessPass: check?.method === "imvu_access_pass",
+        adult: adult.has(l.imvuId),
+        checkedAt: (check?.checkedAt ?? l.linkedAt).toISOString(),
+        showBadge: l.showBadge,
+        showPresence: l.showPresence,
+        online: live !== undefined,
+        outfit: live?.outfit ?? [],
+      };
+    });
   };
+  const linkView = async (l: Link) => (await linkViews(l.userId, [l]))[0]!;
 
   const audited = (actorId: string | null, action: string, target: string, detail: Record<string, unknown> = {}) =>
     db.insert(audit).values({ actorId, action, target, detail });
@@ -105,6 +117,10 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
     if (online.length === 0) return [];
     const links = await db.select().from(imvuLink).where(inArray(imvuLink.imvuId, online.map((o) => o.imvuId)));
     const mod = viewer !== undefined && isModerator(viewer);
+    const adult = new Set<number>();
+    if (mod) {
+      for (const l of links) if ((await age.adultAccounts(l.userId, [l.imvuId])).has(l.imvuId)) adult.add(l.imvuId);
+    }
     return online.flatMap((o) => {
       const l = links.find((l) => l.imvuId === o.imvuId);
       if (!l || (!l.showPresence && !mod)) return [];
@@ -115,7 +131,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
           badge: l.showBadge,
           since: o.since.toISOString(),
           outfit: o.outfit,
-          ...(mod ? { hidden: !l.showPresence, personId: o.userId, adult: l.ageVerified || l.accessPass } : {}),
+          ...(mod ? { hidden: !l.showPresence, personId: o.userId, adult: adult.has(o.imvuId) } : {}),
         },
       ];
     });
@@ -249,7 +265,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
           .where(and(eq(session.userId, me.id), ilike(session.userAgent, "t5de-proxy%"), sql`${session.expiresAt} > now()`));
         return {
           person: personView(me),
-          links: links.map(linkView),
+          links: await linkViews(me.id, links),
           challenges: challenges.map((c) => ({
             imvuId: c.imvuId,
             username: c.username,
@@ -322,13 +338,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
             throw new Problem(403, "link_cap", `You can link up to ${me.linkCap} IMVU accounts. Ask a moderator if you need more.`);
           const [prev] = await tx.select().from(imvuLink).where(eq(imvuLink.imvuId, found.id));
           const moved = prev !== undefined && prev.userId !== me.id;
-          const values = {
-            userId: me.id,
-            username: found.username,
-            ageVerified: found.ageVerified,
-            accessPass: found.accessPass,
-            checkedAt: new Date(),
-          };
+          const values = { userId: me.id, username: found.username };
           let link: Link;
           if (!prev) {
             [link] = (await tx.insert(imvuLink).values({ imvuId: found.id, pairwiseId: randomID(), ...values }).returning()) as [Link];
@@ -352,9 +362,12 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
           });
           return { link, moved, previousOwner: prev?.userId };
         });
+        // Age from IMVU, for this account; a moved account's earlier checks belonged to its previous owner.
+        if (result.moved) await age.forgetAccount(found.id);
+        await age.record({ userId: me.id, imvuId: found.id }, "imvu", imvuResult(found));
         if (result.moved) realtime.unlinked(result.previousOwner!, found.id);
         realtime.linked(me.id, found.id);
-        return { link: linkView(result.link), moved: result.moved };
+        return { link: await linkView(result.link), moved: result.moved };
       },
       { signedIn: true, params: imvuIdParam },
     )
@@ -378,7 +391,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
           })
           .where(eq(imvuLink.imvuId, params.imvu))
           .returning();
-        return { link: linkView(l!) };
+        return { link: await linkView(l!) };
       },
       {
         signedIn: true,
@@ -391,12 +404,9 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
       async ({ me, params }) => {
         await ownLink(me, params.imvu);
         const found = await imvuCall(me, () => imvu.byId(params.imvu));
-        const [l] = await db
-          .update(imvuLink)
-          .set({ username: found.username, ageVerified: found.ageVerified, accessPass: found.accessPass, checkedAt: new Date() })
-          .where(eq(imvuLink.imvuId, params.imvu))
-          .returning();
-        return { link: linkView(l!) };
+        await age.record({ userId: me.id, imvuId: params.imvu }, "imvu", imvuResult(found));
+        const [l] = await db.update(imvuLink).set({ username: found.username }).where(eq(imvuLink.imvuId, params.imvu)).returning();
+        return { link: await linkView(l!) };
       },
       { signedIn: true, params: imvuIdParam },
     )
@@ -405,6 +415,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
       async ({ me, params, set }) => {
         const l = await ownLink(me, params.imvu);
         await db.delete(imvuLink).where(eq(imvuLink.imvuId, l.imvuId));
+        await age.forgetAccount(l.imvuId);
         realtime.unlinked(me.id, l.imvuId);
         await audited(me.id, "link.remove", String(l.imvuId), { imvu: l.username });
         set.status = 204;
@@ -439,6 +450,80 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
       { signedIn: true, body: t.Object({ code: t.String({ minLength: 4, maxLength: 32 }) }) },
     )
 
+    // Age verification beyond IMVU's: the providers in use, and the person's own checks.
+    .get(
+      "/age",
+      async ({ me }) => ({
+        providers: age.list(),
+        checks: (await age.personChecks(me.id)).map((c) => ({
+          provider: c.provider,
+          method: c.method,
+          status: c.status,
+          overEighteen: c.overEighteen,
+          createdAt: c.createdAt.toISOString(),
+          checkedAt: c.checkedAt?.toISOString() ?? null,
+          expiresAt: c.expiresAt?.toISOString() ?? null,
+        })),
+      }),
+      { signedIn: true },
+    )
+    .post(
+      "/age/:provider/start",
+      async ({ me, params, body }) => {
+        let p;
+        try {
+          p = age.provider(params.provider);
+        } catch {
+          throw new Problem(404, "not_found", "That way of verifying age isn't available.");
+        }
+        if (p.scope !== "person") throw new Problem(400, "invalid", "That one checks an IMVU account: link it instead.");
+        const started = await age.start({ userId: me.id }, p.id, body.returnURL);
+        return started.kind === "done" ? { kind: "done" as const } : started;
+      },
+      { signedIn: true, params: t.Object({ provider: t.String() }), body: t.Object({ returnURL: t.String({ maxLength: 500 }) }) },
+    )
+    .post(
+      "/age/:provider/complete",
+      async ({ params, body }) => {
+        const p = age.provider(params.provider);
+        if (!p.complete) throw new Problem(404, "not_found", "Not found.");
+        try {
+          const c = await age.finish(p.id, body.ref, await p.complete(body.ref, body.response));
+          return { status: c.status, overEighteen: c.overEighteen };
+        } catch (e) {
+          if (e instanceof AgeError) throw new Problem(404, "not_found", "That check isn't waiting for an answer.");
+          throw e;
+        }
+      },
+      { signedIn: true, params: t.Object({ provider: t.String() }), body: t.Object({ ref: t.String(), response: t.Unknown() }) },
+    )
+    // Providers' webhooks: each checks the request is really from it.
+    .post(
+      "/age/webhook/:provider",
+      async ({ params, request, set }) => {
+        let p;
+        try {
+          p = age.provider(params.provider);
+        } catch {
+          throw new Problem(404, "not_found", "Not found.");
+        }
+        if (!p.webhook) throw new Problem(404, "not_found", "Not found.");
+        let answer;
+        try {
+          answer = await p.webhook(request);
+        } catch {
+          throw new Problem(401, "forbidden", "Not from the provider.");
+        }
+        try {
+          await age.finish(p.id, answer.ref, answer.result);
+        } catch (e) {
+          if (!(e instanceof AgeError)) throw e; // already finished: webhooks can repeat
+        }
+        set.status = 204;
+      },
+      { params: t.Object({ provider: t.String() }), parse: "none" },
+    )
+
     // The console.
     .get(
       "/console",
@@ -496,7 +581,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
           .select({ n: count() })
           .from(session)
           .where(and(eq(session.userId, p.id), ilike(session.userAgent, "t5de-proxy%"), sql`${session.expiresAt} > now()`));
-        return { person: personView(p), links: links.map(linkView), computers: computers?.n ?? 0 };
+        return { person: personView(p), links: await linkViews(p.id, links), computers: computers?.n ?? 0 };
       },
       { moderator: true },
     )
@@ -578,7 +663,7 @@ export function createApp({ db, auth, imvu, realtime: rt }: Deps) {
     .get("/health", () => ({ ok: true }))
     .use(api);
 
-  return { app, realtime };
+  return { app, realtime, age };
 }
 
 export type App = ReturnType<typeof createApp>["app"];