From 682fd550fad8742364777c8067a696703f38829e Mon Sep 17 00:00:00 2001
From: Benjamin Kitt <ben@thepuddle.com>
Date: Fri, 27 Mar 2026 22:30:02 -0500
Subject: [PATCH 1/2] fix(core): remove extra arg in claude passthrough
 translateRequest call

The second translateRequest call in the claude->openai->claude passthrough
path had an extra `translatedBody` argument before `stream`, shifting all
parameters by one. This caused the `stream` field in the upstream request
to be set to an object instead of a boolean, producing:
  "stream: Input should be a valid boolean"

Co-Authored-By: Craft Agent <agents-noreply@craft.do>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 open-sse/handlers/chatCore.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/open-sse/handlers/chatCore.ts b/open-sse/handlers/chatCore.ts
index 47a8d37836..03f5c6692c 100644
--- a/open-sse/handlers/chatCore.ts
+++ b/open-sse/handlers/chatCore.ts
@@ -462,7 +462,6 @@ export async function handleChatCore({
         FORMATS.CLAUDE,
         model,
         { ...translatedBody, _disableToolPrefix: true },
-        translatedBody,
         stream,
         credentials,
         provider,

From 8d742d79387292f86cf545d57a9b17e0fd0bdd92 Mon Sep 17 00:00:00 2001
From: Benjamin Kitt <ben@thepuddle.com>
Date: Fri, 27 Mar 2026 22:38:34 -0500
Subject: [PATCH 2/2] test: add regression tests for stream boolean in claude
 passthrough

Three tests covering the fixed bug where translateRequest received an
object instead of a boolean for the stream parameter:
- stream=true round-trip produces boolean true
- stream=false round-trip produces boolean false
- guard test documenting that passing an object as stream breaks typing

Co-Authored-By: Craft Agent <agents-noreply@craft.do>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 ...claude-passthrough-stream-boolean.test.mjs | 122 ++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 tests/unit/claude-passthrough-stream-boolean.test.mjs

diff --git a/tests/unit/claude-passthrough-stream-boolean.test.mjs b/tests/unit/claude-passthrough-stream-boolean.test.mjs
new file mode 100644
index 0000000000..6c59cd3378
--- /dev/null
+++ b/tests/unit/claude-passthrough-stream-boolean.test.mjs
@@ -0,0 +1,122 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { translateRequest } = await import("../../open-sse/translator/index.ts");
+const { FORMATS } = await import("../../open-sse/translator/formats.ts");
+
+/**
+ * Regression: claude-to-claude passthrough translateRequest was called with
+ * an extra argument (the previous translatedBody object) before the stream
+ * parameter, causing stream to receive an object instead of a boolean.
+ * Upstream Anthropic rejected with: "stream: Input should be a valid boolean"
+ *
+ * Fix: open-sse/handlers/chatCore.ts — removed stray translatedBody arg.
+ */
+
+test("Claude passthrough: stream field must be a boolean (stream=true)", () => {
+  const body = {
+    model: "claude-sonnet-4-6",
+    max_tokens: 1024,
+    stream: true,
+    messages: [{ role: "user", content: [{ type: "text", text: "Hello" }] }],
+  };
+
+  // Simulate the claude->openai->claude round-trip from chatCore passthrough
+  const openaiBody = translateRequest(
+    FORMATS.CLAUDE,
+    FORMATS.OPENAI,
+    body.model,
+    structuredClone(body),
+    true,
+    null,
+    null,
+    null
+  );
+
+  const result = translateRequest(
+    FORMATS.OPENAI,
+    FORMATS.CLAUDE,
+    body.model,
+    { ...openaiBody, _disableToolPrefix: true },
+    true,
+    null,
+    null,
+    null
+  );
+
+  assert.equal(typeof result.stream, "boolean", "stream must be a boolean, not an object");
+  assert.equal(result.stream, true);
+});
+
+test("Claude passthrough: stream field must be a boolean (stream=false)", () => {
+  const body = {
+    model: "claude-sonnet-4-6",
+    max_tokens: 1024,
+    stream: false,
+    messages: [{ role: "user", content: [{ type: "text", text: "Hello" }] }],
+  };
+
+  const openaiBody = translateRequest(
+    FORMATS.CLAUDE,
+    FORMATS.OPENAI,
+    body.model,
+    structuredClone(body),
+    false,
+    null,
+    null,
+    null
+  );
+
+  const result = translateRequest(
+    FORMATS.OPENAI,
+    FORMATS.CLAUDE,
+    body.model,
+    { ...openaiBody, _disableToolPrefix: true },
+    false,
+    null,
+    null,
+    null
+  );
+
+  assert.equal(typeof result.stream, "boolean", "stream must be a boolean, not an object");
+  assert.equal(result.stream, false);
+});
+
+test("Claude passthrough: passing an object as stream propagates invalid type (guard)", () => {
+  const body = {
+    model: "claude-sonnet-4-6",
+    max_tokens: 1024,
+    messages: [{ role: "user", content: [{ type: "text", text: "Hello" }] }],
+  };
+
+  const openaiBody = translateRequest(
+    FORMATS.CLAUDE,
+    FORMATS.OPENAI,
+    body.model,
+    structuredClone(body),
+    true,
+    null,
+    null,
+    null
+  );
+
+  // Simulate the old bug: passing openaiBody (an object) where stream should be
+  const result = translateRequest(
+    FORMATS.OPENAI,
+    FORMATS.CLAUDE,
+    body.model,
+    { ...openaiBody, _disableToolPrefix: true },
+    openaiBody, // BUG: object instead of boolean
+    null,
+    null,
+    null
+  );
+
+  // This test documents the bug: if an object is passed as stream, it ends up
+  // in the translated body as a non-boolean, which Anthropic rejects.
+  assert.notEqual(
+    typeof result.stream,
+    "boolean",
+    "passing an object as stream should produce a non-boolean (documents the bug)"
+  );
+});