From f1fcdbfa6edc4abc5efc64af6e70ca428f75e8de Mon Sep 17 00:00:00 2001
From: Will Gordon <wgordon@redhat.com>
Date: Tue, 28 Jul 2026 10:49:52 -0400
Subject: [PATCH] fix(executors): route current Claude generations through
 Vertex partner endpoint (#8852)

* fix(executors): route current Claude generations through Vertex partner endpoint

PARTNER_MODELS pinned three Claude 3.x prefixes (claude-3-5-sonnet,
claude-3-opus, claude-3-haiku). Every newer Claude generation on Vertex
(claude-sonnet-4-6, claude-haiku-4-5, etc.) fell through to the
Google-publisher branch instead, producing an invalid
publishers/google/models/claude-... path.

Replace the pinned prefixes with a single generic "claude-" prefix:
any Claude model on Vertex is always an Anthropic partner model, never
a Google one, so this can't go stale again the way pinned version
strings did.

Fixes #1985

* docs: add changelog fragment for #8852
---
 .../8852-vertex-claude-partner-models.md      |  1 +
 open-sse/executors/vertex.ts                  |  7 +++---
 tests/unit/executor-vertex-extended.test.ts   | 22 +++++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/fixes/8852-vertex-claude-partner-models.md

diff --git a/changelog.d/fixes/8852-vertex-claude-partner-models.md b/changelog.d/fixes/8852-vertex-claude-partner-models.md
new file mode 100644
index 0000000000..b5b616fd47
--- /dev/null
+++ b/changelog.d/fixes/8852-vertex-claude-partner-models.md
@@ -0,0 +1 @@
+- **fix(executors):** Vertex AI now routes current-generation Claude models (`claude-sonnet-4-6`, `claude-haiku-4-5`, etc.) through the partner endpoint instead of misrouting them as Google-publisher models ([#8852](https://github.com/diegosouzapw/OmniRoute/pull/8852)) — thanks @wgordon17
diff --git a/open-sse/executors/vertex.ts b/open-sse/executors/vertex.ts
index 4ca1a1ab05..0344a456d6 100644
--- a/open-sse/executors/vertex.ts
+++ b/open-sse/executors/vertex.ts
@@ -116,9 +116,10 @@ export async function getAccessToken(sa: ServiceAccount): Promise<string> {
 }
 
 const PARTNER_MODELS = new Set([
-  "claude-3-5-sonnet",
-  "claude-3-opus",
-  "claude-3-haiku",
+  // Generic prefix, not pinned to a version: every Claude model on Vertex is an Anthropic
+  // partner model, never a Google-publisher one. Pinned prefixes (e.g. "claude-3-5-sonnet")
+  // silently break every time Anthropic ships a new generation — see issue #1985.
+  "claude-",
   "deepseek-v3",
   "deepseek-v3.2",
   "deepseek-v4",
diff --git a/tests/unit/executor-vertex-extended.test.ts b/tests/unit/executor-vertex-extended.test.ts
index f7ac599518..b8cbbe5900 100644
--- a/tests/unit/executor-vertex-extended.test.ts
+++ b/tests/unit/executor-vertex-extended.test.ts
@@ -90,6 +90,28 @@ test("VertexExecutor.buildUrl routes partner and org-prefixed models to the glob
   );
 });
 
+test("VertexExecutor.buildUrl routes current-generation Claude models to the global partner endpoint (#1985)", () => {
+  const executor = new VertexExecutor();
+
+  // These model IDs post-date the old pinned "claude-3-5-sonnet" / "claude-3-opus" /
+  // "claude-3-haiku" prefixes and were previously misrouted to the Google-publisher path.
+  const claude4Sonnet = executor.buildUrl("claude-sonnet-4-6", false, 0, {
+    apiKey: createServiceAccountJson({ projectId: "proj-claude" }),
+  });
+  const claude4Haiku = executor.buildUrl("claude-haiku-4-5@20251001", true, 0, {
+    apiKey: createServiceAccountJson({ projectId: "proj-claude" }),
+  });
+
+  assert.equal(
+    claude4Sonnet,
+    "https://aiplatform.googleapis.com/v1/projects/proj-claude/locations/global/endpoints/openapi/chat/completions"
+  );
+  assert.equal(
+    claude4Haiku,
+    "https://aiplatform.googleapis.com/v1/projects/proj-claude/locations/global/endpoints/openapi/chat/completions"
+  );
+});
+
 test("VertexExecutor.buildHeaders includes Bearer token and SSE Accept only for streaming", () => {
   const executor = new VertexExecutor();
   const streamHeaders = executor.buildHeaders({ accessToken: "ya29.stream" }, true);