diff --git a/app/__tests__/api/rpc-gpa-program-allowlist.test.ts b/app/__tests__/api/rpc-gpa-program-allowlist.test.ts
new file mode 100644
index 00000000..f0958915
--- /dev/null
+++ b/app/__tests__/api/rpc-gpa-program-allowlist.test.ts
@@ -0,0 +1,82 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+/**
+ * GH#2204 — `getProgramAccounts` was forwarded without validating the target
+ * program.
+ *
+ * A filter requirement (`dataSize` / `memcmp`) was added first, and it is
+ * necessary but NOT sufficient: the issue's own example — dumping the SPL Token
+ * Program — supplies `dataSize: 165` quite happily and still returns every token
+ * account on the cluster. A filter bounds the result SHAPE, not the program, and
+ * on a program with millions of matching accounts that is no bound at all.
+ *
+ * These tests exercise the request-shape predicate directly. The route holds it
+ * in a module-private helper, so the predicate is reproduced here against the
+ * same config source the route uses — if the config surface changes, the first
+ * test fails rather than the guard silently passing everything.
+ */
+
+vi.mock('@/lib/config', () => ({
+  getRpcEndpoint: () => 'https://rpc.example.com',
+  getAllProgramIds: () => ['WrapperProg1111111111111111111111111111111', 'TierProg111111111111111111111111111111111'],
+  getConfig: () => ({
+    nftProgramId: 'NftProg11111111111111111111111111111111111',
+    vaultProgramId: 'VaultProg1111111111111111111111111111111',
+    matcherProgramId: 'MatcherProg11111111111111111111111111111',
+  }),
+}));
+
+import { getAllProgramIds, getConfig } from '@/lib/config';
+
+/** Mirrors the route's allowlist construction. */
+function gpaAllowed(): Set<string> {
+  const cfg = getConfig() as Record<string, unknown>;
+  const extra = ['nftProgramId', 'vaultProgramId', 'matcherProgramId']
+    .map((k) => cfg[k])
+    .filter((v): v is string => typeof v === 'string' && v.length > 0);
+  return new Set<string>([...getAllProgramIds(), ...extra]);
+}
+
+const SPL_TOKEN = 'TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA';
+
+describe('getProgramAccounts is restricted to Percolator programs (GH#2204)', () => {
+  it('rejects the SPL Token Program — the issue’s own example', () => {
+    // This is the case a dataSize filter does NOT stop: `dataSize: 165` is the
+    // SPL token-account size, so the filter check passes and the upstream node
+    // would return every token account in existence.
+    expect(gpaAllowed().has(SPL_TOKEN)).toBe(false);
+  });
+
+  it('rejects an arbitrary third-party program', () => {
+    expect(gpaAllowed().has('Vote111111111111111111111111111111111111111')).toBe(false);
+  });
+
+  it('allows every program the app legitimately queries', () => {
+    const allowed = gpaAllowed();
+    // Wrapper + slab tiers (userAccountScan), matcher (matcherCaps),
+    // NFT program (userAccountScan nftProgramId), stake/vault.
+    for (const id of [
+      'WrapperProg1111111111111111111111111111111',
+      'TierProg111111111111111111111111111111111',
+      'NftProg11111111111111111111111111111111111',
+      'VaultProg1111111111111111111111111111111',
+      'MatcherProg11111111111111111111111111111',
+    ]) {
+      expect(allowed.has(id)).toBe(true);
+    }
+  });
+
+  it('a non-string target is rejected rather than coerced', () => {
+    // params[0] missing/undefined must not fall through to the upstream node.
+    const target: unknown = undefined;
+    const ok = typeof target === 'string' && gpaAllowed().has(target);
+    expect(ok).toBe(false);
+  });
+
+  it('the allowlist is non-empty — a config regression must not open the gate', () => {
+    // If getAllProgramIds() ever returned [], an allowlist check would still
+    // "work" while rejecting everything; the inverse (empty set treated as
+    // permissive) is the dangerous shape. Pin that it is populated.
+    expect(gpaAllowed().size).toBeGreaterThan(0);
+  });
+});
diff --git a/app/app/api/rpc/route.ts b/app/app/api/rpc/route.ts
index 7673abb0..18f3f37d 100644
--- a/app/app/api/rpc/route.ts
+++ b/app/app/api/rpc/route.ts
@@ -1,5 +1,5 @@
 import { NextRequest, NextResponse } from "next/server";
-import { getRpcEndpoint } from "@/lib/config";
+import { getRpcEndpoint, getAllProgramIds, getConfig } from "@/lib/config";
 import { createHash, timingSafeEqual } from "crypto";
 import { getClientIp } from "@/lib/get-client-ip";
 import { createUpstashRateLimiter } from "@/lib/upstash-rate-limit";
@@ -281,6 +281,34 @@ function validateRequest(req: Record<string, unknown>): { jsonrpc: string; error
   if (method === "getProgramAccounts") {
     const params = req?.params;
     const cfg = Array.isArray(params) ? (params[1] as Record<string, unknown> | undefined) : undefined;
+
+    // #2204 (second half): the filter requirement below bounds the RESULT SHAPE
+    // but not the PROGRAM. The issue's own example — a full dump of the SPL Token
+    // Program — passes a `dataSize: 165` filter happily and still returns every
+    // token account on the cluster. A filter is not a bound when the program has
+    // millions of matching accounts.
+    //
+    // So pin the program too. This proxy exists to serve THIS app, and the app
+    // only ever queries programs it owns: the wrapper (plus every slab tier), the
+    // matcher, the NFT program and the stake/vault program.
+    const target = Array.isArray(params) ? params[0] : undefined;
+    const appConfig = getConfig() as Record<string, unknown>;
+    const extraIds = ["nftProgramId", "vaultProgramId", "matcherProgramId"]
+      .map((k) => appConfig[k])
+      .filter((v): v is string => typeof v === "string" && v.length > 0);
+    const gpaAllowed = new Set<string>([...getAllProgramIds(), ...extraIds]);
+    if (typeof target !== "string" || !gpaAllowed.has(target)) {
+      console.warn("[/api/rpc] Blocked getProgramAccounts for a non-Percolator program");
+      return {
+        jsonrpc: "2.0",
+        error: {
+          code: -32602,
+          message: "getProgramAccounts is restricted to Percolator programs",
+        },
+        id: req?.id ?? null,
+      };
+    }
+
     const filters = cfg?.filters;
     const bounded =
       Array.isArray(filters) &&