diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c910f29abd..7549616372b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -307,6 +307,7 @@ Docs: https://docs.openclaw.ai
 - Signal/inbound attachment fan-in: forward all successfully fetched inbound attachments through `MediaPaths`/`MediaUrls`/`MediaTypes` (instead of only the first), and improve multi-attachment placeholder summaries in mention-gated pending history. (#39212) Thanks @joeykrug.
 - Nodes/system.run dispatch-wrapper boundary: keep shell-wrapper approval classification active at the depth boundary so `env` wrapper stacks cannot reach `/bin/sh -c` execution without the expected approval gate. Thanks @tdjackey for reporting.
 - Docker/token persistence on reconfigure: reuse the existing `.env` gateway token during `docker-setup.sh` reruns and align compose token env defaults, so Docker installs stop silently rotating tokens and breaking existing dashboard sessions. Landed from contributor PR #33097 by @chengzhichao-xydt. Thanks @chengzhichao-xydt.
+- Agents/strict OpenAI turn ordering: apply assistant-first transcript bootstrap sanitization to strict OpenAI-compatible providers (for example vLLM/Gemma via `openai-completions`) without adding Google-specific session markers, preventing assistant-first history rejections. (#39252) Thanks @scoootscooob.
 
 ## 2026.3.2
 
diff --git a/src/agents/pi-embedded-runner.sanitize-session-history.test.ts b/src/agents/pi-embedded-runner.sanitize-session-history.test.ts
index e216a45f4f3..4fb4659c15d 100644
--- a/src/agents/pi-embedded-runner.sanitize-session-history.test.ts
+++ b/src/agents/pi-embedded-runner.sanitize-session-history.test.ts
@@ -255,6 +255,34 @@ describe("sanitizeSessionHistory", () => {
     );
   });
 
+  it("prepends a bootstrap user turn for strict OpenAI-compatible assistant-first history", async () => {
+    setNonGoogleModelApi();
+    const sessionEntries: Array<{ type: string; customType: string; data: unknown }> = [];
+    const sessionManager = makeInMemorySessionManager(sessionEntries);
+    const messages = castAgentMessages([
+      {
+        role: "assistant",
+        content: [{ type: "text", text: "hello from previous turn" }],
+      },
+    ]);
+
+    const result = await sanitizeSessionHistory({
+      messages,
+      modelApi: "openai-completions",
+      provider: "vllm",
+      modelId: "gemma-3-27b",
+      sessionManager,
+      sessionId: TEST_SESSION_ID,
+    });
+
+    expect(result[0]?.role).toBe("user");
+    expect((result[0] as { content?: unknown } | undefined)?.content).toBe("(session bootstrap)");
+    expect(result[1]?.role).toBe("assistant");
+    expect(
+      sessionEntries.some((entry) => entry.customType === "google-turn-ordering-bootstrap"),
+    ).toBe(false);
+  });
+
   it("annotates inter-session user messages before context sanitization", async () => {
     setNonGoogleModelApi();
 
diff --git a/src/agents/pi-embedded-runner/google.ts b/src/agents/pi-embedded-runner/google.ts
index 4daf30552b3..265593f03e0 100644
--- a/src/agents/pi-embedded-runner/google.ts
+++ b/src/agents/pi-embedded-runner/google.ts
@@ -594,10 +594,19 @@ export async function sanitizeSessionHistory(params: {
     return sanitizedOpenAI;
   }
 
-  return applyGoogleTurnOrderingFix({
-    messages: sanitizedOpenAI,
-    modelApi: params.modelApi,
-    sessionManager: params.sessionManager,
-    sessionId: params.sessionId,
-  }).messages;
+  // Google models use the full wrapper with logging and session markers.
+  if (isGoogleModelApi(params.modelApi)) {
+    return applyGoogleTurnOrderingFix({
+      messages: sanitizedOpenAI,
+      modelApi: params.modelApi,
+      sessionManager: params.sessionManager,
+      sessionId: params.sessionId,
+    }).messages;
+  }
+
+  // Strict OpenAI-compatible providers (vLLM, Gemma, etc.) also reject
+  // conversations that start with an assistant turn (e.g. delivery-mirror
+  // messages after /new).  Apply the same ordering fix without the
+  // Google-specific session markers.  See #38962.
+  return sanitizeGoogleTurnOrdering(sanitizedOpenAI);
 }
diff --git a/src/agents/transcript-policy.test.ts b/src/agents/transcript-policy.test.ts
index 796cd2f43ed..15c03250eda 100644
--- a/src/agents/transcript-policy.test.ts
+++ b/src/agents/transcript-policy.test.ts
@@ -60,6 +60,8 @@ describe("resolveTranscriptPolicy", () => {
       modelId: "kimi-k2.5",
       modelApi: "openai-completions",
     });
+    expect(policy.applyGoogleTurnOrdering).toBe(true);
+    expect(policy.validateGeminiTurns).toBe(true);
     expect(policy.validateAnthropicTurns).toBe(true);
   });
 
@@ -120,12 +122,25 @@ describe("resolveTranscriptPolicy", () => {
     expect(policy.preserveSignatures).toBe(false);
   });
 
+  it("enables turn-ordering and assistant-merge for strict OpenAI-compatible providers (#38962)", () => {
+    const policy = resolveTranscriptPolicy({
+      provider: "vllm",
+      modelId: "gemma-3-27b",
+      modelApi: "openai-completions",
+    });
+    expect(policy.applyGoogleTurnOrdering).toBe(true);
+    expect(policy.validateGeminiTurns).toBe(true);
+    expect(policy.validateAnthropicTurns).toBe(true);
+  });
+
   it("keeps OpenRouter on its existing turn-validation path", () => {
     const policy = resolveTranscriptPolicy({
       provider: "openrouter",
       modelId: "openai/gpt-4.1",
       modelApi: "openai-completions",
     });
+    expect(policy.applyGoogleTurnOrdering).toBe(false);
+    expect(policy.validateGeminiTurns).toBe(false);
     expect(policy.validateAnthropicTurns).toBe(false);
   });
 });
diff --git a/src/agents/transcript-policy.ts b/src/agents/transcript-policy.ts
index 189dd7a3e80..4296f62394a 100644
--- a/src/agents/transcript-policy.ts
+++ b/src/agents/transcript-policy.ts
@@ -127,8 +127,8 @@ export function resolveTranscriptPolicy(params: {
     sanitizeThoughtSignatures: isOpenAi ? undefined : sanitizeThoughtSignatures,
     sanitizeThinkingSignatures: false,
     dropThinkingBlocks,
-    applyGoogleTurnOrdering: !isOpenAi && isGoogle,
-    validateGeminiTurns: !isOpenAi && isGoogle,
+    applyGoogleTurnOrdering: !isOpenAi && (isGoogle || isStrictOpenAiCompatible),
+    validateGeminiTurns: !isOpenAi && (isGoogle || isStrictOpenAiCompatible),
     validateAnthropicTurns: !isOpenAi && (isAnthropic || isStrictOpenAiCompatible),
     allowSyntheticToolResults: !isOpenAi && (isGoogle || isAnthropic),
   };