Merge pull request #696 from benjaminkitt/fix/input-stream-invalid-boolean

Reviewed and approved via consolidated analysis. Fix is surgical (1 line removed) with 122 lines of regression tests covering stream=true, stream=false and guard scenarios. Resolves #677.

open-sse/handlers/chatCore.ts

@@ -462,7 +462,6 @@ export async function handleChatCore({
         FORMATS.CLAUDE,
         model,
         { ...translatedBody, _disableToolPrefix: true },
-        translatedBody,
         stream,
         credentials,
         provider,

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)"
+  );
+});