diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ccd1882d4..e626903711 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,8 @@
 
 - **antigravity/gemini tool calls (`400 Unknown name "multipleOf"`):** requests routed to antigravity/gemini models with tools that declare a `multipleOf` numeric constraint failed with a hard upstream `400` (`Invalid JSON payload received. Unknown name "multipleOf"`). `multipleOf` is not part of the Gemini/antigravity OpenAPI 3.0 schema subset and was not being stripped from `function_declarations`. It is now removed at every schema level (top-level, nested, and array `items`), alongside the other unsupported constraints; `minimum`/`maximum` remain untouched. Regression guard: `tests/unit/gemini-multipleof-2309.test.ts`. (thanks @abil0321)
 
+- **cline (empty/false-502 non-streaming responses):** the Cline gateway can wrap OpenAI-compatible chat completions in a `{ success, data: { choices, usage, … } }` envelope. The non-streaming path checked the top-level body for empty content before unwrapping, so a valid Cline response was treated as malformed. The body is now unwrapped via `unwrapClineNonStreamingEnvelope()` right after the provider-envelope unwrap and before the empty-content check, closing the remaining gap from #5956/#5924. Regression guard: `tests/unit/cline-response-envelope.test.ts`. ([#5956](https://github.com/diegosouzapw/OmniRoute/issues/5956) — thanks @KooshaPari)
+
 ### 📝 Maintenance
 
 - **test (deflake `setup-claude`):** `tests/unit/cli/setup-claude.test.ts` failed ~50% of runs with `Unable to deserialize cloned data due to invalid or unsupported version` at file teardown (all subtests passed), randomly reddening `Unit Tests fast-path (2/2)` / `Fast Quality Gates` across the PR→release queue. Root cause: `node --test` streams each file's report to the parent as V8-serialized frames on fd 1 (stdout), and the CLI helper under test (`syncClaudeProfilesFromModels`) prints progress via `console.log` — that stdout output interleaved with the serialized frames and corrupted the stream. The test now silences the stdout-writing `console` methods for the file's duration (no assertion inspects stdout), making it deterministic (15/15 green locally). ([#5959](https://github.com/diegosouzapw/OmniRoute/issues/5959))
diff --git a/config/quality/file-size-baseline.json b/config/quality/file-size-baseline.json
index 1e15fe5d1f..5c9e0e3db2 100644
--- a/config/quality/file-size-baseline.json
+++ b/config/quality/file-size-baseline.json
@@ -311,7 +311,7 @@
     "tests/unit/translator-helper-branches.test.ts": 870,
     "tests/unit/translator-openai-responses-req.test.ts": 1172,
     "tests/unit/translator-openai-to-gemini.test.ts": 1579,
-    "tests/unit/translator-openai-to-kiro.test.ts": 1088,
+    "tests/unit/translator-openai-to-kiro.test.ts": 1093,
     "tests/unit/translator-resp-gemini-to-openai.test.ts": 1234,
     "tests/unit/usage-service-hardening.test.ts": 1633,
     "tests/unit/vscode-token-routes.test.ts": 1212,
diff --git a/open-sse/handlers/chatCore.ts b/open-sse/handlers/chatCore.ts
index 21500f2c30..45a58c3f57 100644
--- a/open-sse/handlers/chatCore.ts
+++ b/open-sse/handlers/chatCore.ts
@@ -252,6 +252,7 @@ import { isCompactResponsesEndpoint } from "../executors/codex.ts";
 import { buildCodexQuotaPersistence } from "./chatCore/codexQuota.ts";
 import { invalidateCodexQuotaCache } from "../services/codexQuotaFetcher.ts";
 import { translateNonStreamingResponse } from "./responseTranslator.ts";
+import { unwrapClineNonStreamingEnvelope } from "./chatCore/clineResponseEnvelope.ts";
 import { extractUsageFromResponse } from "./usageExtractor.ts";
 import {
   sanitizeOpenAIResponse,
@@ -3612,6 +3613,7 @@ export async function handleChatCore({
       }
       responseBody = unwrapped;
     }
+    responseBody = unwrapClineNonStreamingEnvelope(provider, responseBody);
 
     // Check for empty content response (fake success) - trigger fallback
     if (isEmptyContentResponse(responseBody)) {
diff --git a/open-sse/handlers/chatCore/clineResponseEnvelope.ts b/open-sse/handlers/chatCore/clineResponseEnvelope.ts
new file mode 100644
index 0000000000..0882ef3718
--- /dev/null
+++ b/open-sse/handlers/chatCore/clineResponseEnvelope.ts
@@ -0,0 +1,25 @@
+type JsonRecord = Record<string, unknown>;
+
+function isRecord(value: unknown): value is JsonRecord {
+  return !!value && typeof value === "object" && !Array.isArray(value);
+}
+
+function hasOpenAIChoices(value: unknown): boolean {
+  return isRecord(value) && Array.isArray(value.choices);
+}
+
+export function unwrapClineNonStreamingEnvelope(provider: string, responseBody: unknown): unknown {
+  if (provider !== "cline" || !isRecord(responseBody)) {
+    return responseBody;
+  }
+
+  const data = responseBody.data;
+  if (!hasOpenAIChoices(data)) {
+    return responseBody;
+  }
+
+  return {
+    ...data,
+    usage: isRecord(data) && data.usage !== undefined ? data.usage : responseBody.usage,
+  };
+}
diff --git a/stryker.conf.json b/stryker.conf.json
index 2b4a90dec9..b8dac2b67c 100644
--- a/stryker.conf.json
+++ b/stryker.conf.json
@@ -92,6 +92,7 @@
       "tests/unit/claude-passthrough-stream-boolean.test.ts",
       "tests/unit/claude-passthrough-thinking-2454.test.ts",
       "tests/unit/cli-simulate.test.ts",
+      "tests/unit/cline-response-envelope.test.ts",
       "tests/unit/clinepass-provider.test.ts",
       "tests/unit/codex-failover.test.ts",
       "tests/unit/codex-session-affinity-reset-aware-5903.test.ts",
diff --git a/tests/unit/cline-response-envelope.test.ts b/tests/unit/cline-response-envelope.test.ts
new file mode 100644
index 0000000000..f087ad923a
--- /dev/null
+++ b/tests/unit/cline-response-envelope.test.ts
@@ -0,0 +1,27 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { unwrapClineNonStreamingEnvelope } = await import(
+  "../../open-sse/handlers/chatCore/clineResponseEnvelope.ts"
+);
+
+test("unwrapClineNonStreamingEnvelope extracts Cline wrapped chat completions", () => {
+  const wrapped = {
+    success: true,
+    data: {
+      id: "chatcmpl_cline",
+      model: "cline/model",
+      choices: [{ index: 0, message: { role: "assistant", content: "ok" } }],
+      usage: { prompt_tokens: 3, completion_tokens: 2, total_tokens: 5 },
+    },
+  };
+
+  assert.deepEqual(unwrapClineNonStreamingEnvelope("cline", wrapped), wrapped.data);
+});
+
+test("unwrapClineNonStreamingEnvelope keeps non-Cline and malformed envelopes untouched", () => {
+  const wrapped = { success: true, data: { message: "missing choices" } };
+
+  assert.equal(unwrapClineNonStreamingEnvelope("openai", wrapped), wrapped);
+  assert.equal(unwrapClineNonStreamingEnvelope("cline", wrapped), wrapped);
+});