From f4fa983a9f683971409625dd6689a4e542b3ec95 Mon Sep 17 00:00:00 2001
From: Diego Rodrigues de Sa e Souza
 <8016841+diegosouzapw@users.noreply.github.com>
Date: Tue, 23 Jun 2026 21:51:29 -0300
Subject: [PATCH] fix(perplexity): validate API keys via /v1/models endpoint
 (#4654)
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Integrated into release/v3.8.36 — port (rebuilt from stale base; defining commit cherry-picked clean over release tip, release-green validated)
---
 .../providers/registry/perplexity/index.ts    |  5 ++
 .../perplexity-key-validation-models.test.ts  | 50 +++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 tests/unit/perplexity-key-validation-models.test.ts

diff --git a/open-sse/config/providers/registry/perplexity/index.ts b/open-sse/config/providers/registry/perplexity/index.ts
index 97f1844ad9..14b90d413d 100644
--- a/open-sse/config/providers/registry/perplexity/index.ts
+++ b/open-sse/config/providers/registry/perplexity/index.ts
@@ -6,6 +6,11 @@ export const perplexityProvider: RegistryEntry = {
   format: "openai",
   executor: "default",
   baseUrl: "https://api.perplexity.ai/chat/completions",
+  // Perplexity deprecated the unversioned `/models` endpoint (returns 404), so
+  // pin an explicit `modelsUrl` here. Without it, validateOpenAILikeProvider
+  // (src/lib/providers/validation.ts) derives `<baseUrl>/models` via
+  // addModelsSuffix and probes the dead endpoint, misclassifying valid keys.
+  modelsUrl: "https://api.perplexity.ai/v1/models",
   authType: "apikey",
   authHeader: "bearer",
   models: [
diff --git a/tests/unit/perplexity-key-validation-models.test.ts b/tests/unit/perplexity-key-validation-models.test.ts
new file mode 100644
index 0000000000..ee078ea5cb
--- /dev/null
+++ b/tests/unit/perplexity-key-validation-models.test.ts
@@ -0,0 +1,50 @@
+// Regression test for perplexity API key validation.
+//
+// Perplexity deprecated the unversioned `/models` endpoint (returns 404), so
+// our default validation probe — which derives `<baseUrl>/models` from the
+// perplexity registry entry via `addModelsSuffix` — would always fail to
+// confirm a valid key, falling through to the chat-completions probe and
+// often misclassifying live keys as "Invalid". Inspired by upstream
+// 9router fix (see commit message); we port it OmniRoute-style by
+// declaring an explicit `modelsUrl` on the perplexity registry entry.
+
+import { describe, it } from "node:test";
+import assert from "node:assert";
+
+describe("perplexity registry — key validation models endpoint", () => {
+  it("declares a modelsUrl pointing at /v1/models (not the deprecated /models)", async () => {
+    const { getRegistryEntry } = await import(
+      "../../open-sse/config/providerRegistry.ts"
+    );
+    const entry = getRegistryEntry("perplexity");
+    assert.ok(entry, "perplexity must be registered in the execution registry");
+    assert.equal(entry.format, "openai");
+    assert.ok(
+      typeof entry.modelsUrl === "string" && entry.modelsUrl.length > 0,
+      "perplexity registry entry must declare an explicit modelsUrl so key " +
+        "validation does not hit the deprecated <baseUrl>/models endpoint"
+    );
+    assert.equal(
+      entry.modelsUrl,
+      "https://api.perplexity.ai/v1/models",
+      "perplexity modelsUrl must point at the versioned /v1/models endpoint " +
+        "(unversioned /models was deprecated and now returns 404)"
+    );
+  });
+
+  it("does not derive a /models URL that ends in /chat/completions/models", async () => {
+    const { getRegistryEntry } = await import(
+      "../../open-sse/config/providerRegistry.ts"
+    );
+    const entry = getRegistryEntry("perplexity");
+    assert.ok(entry?.modelsUrl, "modelsUrl required");
+    assert.ok(
+      !entry.modelsUrl.includes("/chat/completions"),
+      "modelsUrl must not include /chat/completions"
+    );
+    assert.ok(
+      entry.modelsUrl.endsWith("/v1/models"),
+      "modelsUrl must end with /v1/models"
+    );
+  });
+});