From 244ba22184ac8f52ebe08318d38fc942f6a38fcd Mon Sep 17 00:00:00 2001
From: OmniRoute Ops <ops@nomenak.dev>
Date: Tue, 12 May 2026 09:03:05 +0000
Subject: [PATCH] fix(cliproxyapi): detect Anthropic shape on minimal Capy
 bodies

Discovered post-deploy: simple Capy /v1/messages requests (string content,
no system block) were misdetected as OpenAI-shape and routed to
/v1/chat/completions instead of /v1/messages. CPA then responded with
chat.completion shape, leaking OpenAI shape to Anthropic SDK clients
and skipping the Anthropic CC wire-image cloak.

Strengthen isAnthropicShape with two more strong signals (any one is
decisive):
  - top-level `thinking` field (Anthropic-only; OpenAI uses `reasoning`)
  - top-level `metadata.user_id` (CC wire-image OAuth identifier)

These survive even on minimal bodies where messages[0].content is a
string and no system block is present.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 open-sse/executors/cliproxyapi.ts       | 14 ++++++++++++++
 tests/unit/cliproxyapi-executor.test.ts | 15 +++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/open-sse/executors/cliproxyapi.ts b/open-sse/executors/cliproxyapi.ts
index 601d100e037c..df14e8ff80ee 100644
--- a/open-sse/executors/cliproxyapi.ts
+++ b/open-sse/executors/cliproxyapi.ts
@@ -178,6 +178,20 @@ export class CliproxyapiExecutor extends BaseExecutor {
     // entry inside messages[], not at body level. Accept both string and
     // array-of-content-blocks forms (Anthropic supports both per the docs).
     if (b.system !== undefined) return true;
+    // Strong signal: top-level `thinking` field is Anthropic-only. OpenAI
+    // uses `reasoning` / `reasoning_effort`. Even adaptive/raw Capy shapes
+    // emit thinking, so this catches minimal Capy bodies (string content,
+    // no system block) that would otherwise miss the messages[0].content
+    // array check below.
+    if (b.thinking !== undefined) return true;
+    // Strong signal: top-level `metadata.user_id` is the CC wire-image
+    // identifier; OpenAI request bodies don't carry it.
+    if (
+      b.metadata &&
+      typeof b.metadata === "object" &&
+      (b.metadata as Record<string, unknown>).user_id !== undefined
+    )
+      return true;
     // Strong signal: messages[0].content is an array of Anthropic content blocks
     const msgs = b.messages;
     if (Array.isArray(msgs) && msgs.length > 0) {
diff --git a/tests/unit/cliproxyapi-executor.test.ts b/tests/unit/cliproxyapi-executor.test.ts
index 0d65bf243134..a66c39f9c575 100644
--- a/tests/unit/cliproxyapi-executor.test.ts
+++ b/tests/unit/cliproxyapi-executor.test.ts
@@ -178,15 +178,22 @@ describe("CliproxyapiExecutor", () => {
       assert.equal(result.thinking, undefined);
     });
 
-    it("does not touch thinking on OpenAI-shape bodies", () => {
+    it("does not strip OpenAI-shape bodies (no thinking, no system, string content)", () => {
       const exec = new CliproxyapiExecutor();
       const body = {
         model: "gpt-5.5",
-        messages: [{ role: "user", content: "hi" }],
-        thinking: { type: "adaptive", display: "summarized" },
+        messages: [
+          { role: "system", content: "be brief" },
+          { role: "user", content: "hi" },
+        ],
+        reasoning_effort: "medium",
       };
       const result = exec.transformRequest("gpt-5.5", body, true, {});
-      assert.deepEqual(result.thinking, { type: "adaptive", display: "summarized" });
+      // No Anthropic indicators present, so strips are skipped. Body
+      // passes through with its OpenAI fields preserved.
+      assert.equal(result.reasoning_effort, "medium");
+      assert.equal(result.thinking, undefined);
+      assert.equal(result.output_config, undefined);
     });
   });