diff --git a/open-sse/translator/helpers/responsesApiHelper.ts b/open-sse/translator/helpers/responsesApiHelper.ts
index 01967f6fd0..49ab141f55 100644
--- a/open-sse/translator/helpers/responsesApiHelper.ts
+++ b/open-sse/translator/helpers/responsesApiHelper.ts
@@ -1,105 +1,9 @@
 /**
- * Convert OpenAI Responses API format to standard chat completions format
- * Responses API uses: { input: [...], instructions: "..." }
- * Chat API uses: { messages: [...] }
+ * Convert OpenAI Responses API format to standard chat completions format.
+ * Delegates to the canonical translator to avoid logic duplication.
  */
+import { openaiResponsesToOpenAIRequest } from "../request/openai-responses.ts";
+
 export function convertResponsesApiFormat(body) {
-  if (!body.input) return body;
-
-  const result = { ...body };
-  result.messages = [];
-
-  // Convert instructions to system message
-  if (body.instructions) {
-    result.messages.push({ role: "system", content: body.instructions });
-  }
-
-  // Group items by conversation turn
-  let currentAssistantMsg = null;
-  let pendingToolCalls = [];
-  let pendingToolResults = [];
-
-  for (const item of body.input) {
-    // Determine item type - Droid CLI sends role-based items without 'type' field
-    // Fallback: if no type but has role property, treat as message
-    const itemType = item.type || (item.role ? "message" : null);
-
-    if (itemType === "message") {
-      // Flush each pending assistant message with tool calls
-      if (currentAssistantMsg) {
-        result.messages.push(currentAssistantMsg);
-        currentAssistantMsg = null;
-      }
-      // Flush pending tool results
-      if (pendingToolResults.length > 0) {
-        for (const tr of pendingToolResults) {
-          result.messages.push(tr);
-        }
-        pendingToolResults = [];
-      }
-
-      // Convert content: input_text → text, output_text → text
-      const content = Array.isArray(item.content)
-        ? item.content.map((c) => {
-            if (c.type === "input_text") return { type: "text", text: c.text };
-            if (c.type === "output_text") return { type: "text", text: c.text };
-            return c;
-          })
-        : item.content;
-      result.messages.push({ role: item.role, content });
-    } else if (itemType === "function_call") {
-      // Start or append to assistant message with tool_calls
-      if (!currentAssistantMsg) {
-        currentAssistantMsg = {
-          role: "assistant",
-          content: null,
-          tool_calls: [],
-        };
-      }
-      currentAssistantMsg.tool_calls.push({
-        id: item.call_id,
-        type: "function",
-        function: {
-          name: item.name,
-          arguments: item.arguments,
-        },
-      });
-    } else if (itemType === "function_call_output") {
-      // Flush assistant message first if exists
-      if (currentAssistantMsg) {
-        result.messages.push(currentAssistantMsg);
-        currentAssistantMsg = null;
-      }
-      // Add tool result
-      pendingToolResults.push({
-        role: "tool",
-        tool_call_id: item.call_id,
-        content: typeof item.output === "string" ? item.output : JSON.stringify(item.output),
-      });
-    } else if (itemType === "reasoning") {
-      // Skip reasoning items - they are for display only
-      continue;
-    }
-  }
-
-  // Flush remaining
-  if (currentAssistantMsg) {
-    result.messages.push(currentAssistantMsg);
-  }
-  if (pendingToolResults.length > 0) {
-    for (const tr of pendingToolResults) {
-      result.messages.push(tr);
-    }
-  }
-
-  // Cleanup Responses API specific fields
-  // Note: prompt_cache_key is intentionally preserved — it is used by Codex and other
-  // providers as a cache-affinity signal. Stripping it breaks prompt caching (#517).
-  delete result.input;
-  delete result.instructions;
-  delete result.include;
-  delete result.store;
-  delete result.reasoning;
-
-  return result;
+  return openaiResponsesToOpenAIRequest(null, body, null, null);
 }
diff --git a/tests/unit/responses-translation-fixes.test.mjs b/tests/unit/responses-translation-fixes.test.mjs
new file mode 100644
index 0000000000..ea6a3ca7cd
--- /dev/null
+++ b/tests/unit/responses-translation-fixes.test.mjs
@@ -0,0 +1,35 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { convertResponsesApiFormat } = await import(
+  "../../open-sse/translator/helpers/responsesApiHelper.ts"
+);
+
+test("convertResponsesApiFormat filters orphaned function_call_output items", () => {
+  const body = {
+    model: "gpt-4",
+    input: [
+      {
+        type: "function_call_output",
+        call_id: "orphaned_call",
+        output: "result",
+      },
+    ],
+  };
+  const result = convertResponsesApiFormat(body);
+  const toolMsgs = result.messages.filter((m) => m.role === "tool");
+  assert.equal(toolMsgs.length, 0);
+});
+
+test("convertResponsesApiFormat skips function_call items with empty names", () => {
+  const body = {
+    model: "gpt-4",
+    input: [
+      { type: "function_call", call_id: "c1", name: "", arguments: "{}" },
+      { type: "function_call", call_id: "c2", name: "  ", arguments: "{}" },
+    ],
+  };
+  const result = convertResponsesApiFormat(body);
+  const assistantMsgs = result.messages.filter((m) => m.role === "assistant");
+  assert.equal(assistantMsgs.length, 0);
+});