diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4d185ea9a..84f7a3294 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Models/MiniMax auth header defaults: set `authHeader: true` for both onboarding-generated MiniMax API providers and implicit built-in MiniMax (`minimax`, `minimax-portal`) provider templates so first requests no longer fail with MiniMax `401 authentication_error` due to missing `Authorization` header. Landed from contributor PRs #27622 by @riccoyuanft and #27631 by @kevinWangSheng. (#27600, #15303)
 - Pi image-token usage: stop re-injecting history image blocks each turn, process image references from the current prompt only, and prune already-answered user-image blocks in stored history to prevent runaway token growth. (#27602)
 - BlueBubbles/SSRF: auto-allowlist the configured `serverUrl` hostname for attachment fetches so localhost/private-IP BlueBubbles setups are no longer false-blocked by default SSRF checks. Landed from contributor PR #27648 by @lailoo. (#27599) Thanks @taylorhou for reporting.
 - Security/Gateway node pairing: pin paired-device `platform`/`deviceFamily` metadata across reconnects and bind those fields into device-auth signatures, so reconnect metadata spoofing cannot expand node command allowlists without explicit repair pairing. This ships in the next npm release (`2026.2.26`). Thanks @76embiid21 for reporting.
diff --git a/src/agents/models-config.providers.nvidia.test.ts b/src/agents/models-config.providers.nvidia.test.ts
index 17025cb86..02086283c 100644
--- a/src/agents/models-config.providers.nvidia.test.ts
+++ b/src/agents/models-config.providers.nvidia.test.ts
@@ -1,4 +1,5 @@
 import { mkdtempSync } from "node:fs";
+import { writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
@@ -54,9 +55,38 @@ describe("MiniMax implicit provider (#15275)", () => {
       const providers = await resolveImplicitProviders({ agentDir });
       expect(providers?.minimax).toBeDefined();
       expect(providers?.minimax?.api).toBe("anthropic-messages");
+      expect(providers?.minimax?.authHeader).toBe(true);
       expect(providers?.minimax?.baseUrl).toBe("https://api.minimax.io/anthropic");
     });
   });
+
+  it("should set authHeader for minimax portal provider", async () => {
+    const agentDir = mkdtempSync(join(tmpdir(), "openclaw-test-"));
+    await writeFile(
+      join(agentDir, "auth-profiles.json"),
+      JSON.stringify(
+        {
+          version: 1,
+          profiles: {
+            "minimax-portal:default": {
+              type: "oauth",
+              provider: "minimax-portal",
+              oauth: {
+                access: "token",
+                expires: Date.now() + 60_000,
+              },
+            },
+          },
+        },
+        null,
+        2,
+      ),
+      "utf8",
+    );
+
+    const providers = await resolveImplicitProviders({ agentDir });
+    expect(providers?.["minimax-portal"]?.authHeader).toBe(true);
+  });
 });
 
 describe("vLLM provider", () => {
diff --git a/src/agents/models-config.providers.ts b/src/agents/models-config.providers.ts
index ef7d41c06..b4b5d8102 100644
--- a/src/agents/models-config.providers.ts
+++ b/src/agents/models-config.providers.ts
@@ -480,6 +480,7 @@ function buildMinimaxProvider(): ProviderConfig {
   return {
     baseUrl: MINIMAX_PORTAL_BASE_URL,
     api: "anthropic-messages",
+    authHeader: true,
     models: [
       buildMinimaxTextModel({
         id: MINIMAX_DEFAULT_MODEL_ID,
@@ -515,6 +516,7 @@ function buildMinimaxPortalProvider(): ProviderConfig {
   return {
     baseUrl: MINIMAX_PORTAL_BASE_URL,
     api: "anthropic-messages",
+    authHeader: true,
     models: [
       buildMinimaxTextModel({
         id: MINIMAX_DEFAULT_MODEL_ID,
diff --git a/src/commands/onboard-auth.config-minimax.ts b/src/commands/onboard-auth.config-minimax.ts
index 6314a641d..90a3c5888 100644
--- a/src/commands/onboard-auth.config-minimax.ts
+++ b/src/commands/onboard-auth.config-minimax.ts
@@ -181,6 +181,7 @@ function applyMinimaxApiProviderConfigWithBaseUrl(
     ...existingProviderRest,
     baseUrl: params.baseUrl,
     api: "anthropic-messages",
+    authHeader: true,
     ...(normalizedApiKey?.trim() ? { apiKey: normalizedApiKey } : {}),
     models: mergedModels.length > 0 ? mergedModels : [apiModel],
   };
diff --git a/src/commands/onboard-auth.test.ts b/src/commands/onboard-auth.test.ts
index e8671fa1a..5b671cbed 100644
--- a/src/commands/onboard-auth.test.ts
+++ b/src/commands/onboard-auth.test.ts
@@ -365,6 +365,7 @@ describe("applyMinimaxApiConfig", () => {
     expect(cfg.models?.providers?.minimax).toMatchObject({
       baseUrl: "https://api.minimax.io/anthropic",
       api: "anthropic-messages",
+      authHeader: true,
     });
   });
 
@@ -404,6 +405,7 @@ describe("applyMinimaxApiConfig", () => {
     );
     expect(cfg.models?.providers?.minimax?.baseUrl).toBe("https://api.minimax.io/anthropic");
     expect(cfg.models?.providers?.minimax?.api).toBe("anthropic-messages");
+    expect(cfg.models?.providers?.minimax?.authHeader).toBe(true);
     expect(cfg.models?.providers?.minimax?.apiKey).toBe("old-key");
     expect(cfg.models?.providers?.minimax?.models.map((m) => m.id)).toEqual([
       "old-model",
diff --git a/src/telegram/lane-delivery.ts b/src/telegram/lane-delivery.ts
index 60dbcdf5a..80fbe180c 100644
--- a/src/telegram/lane-delivery.ts
+++ b/src/telegram/lane-delivery.ts
@@ -109,11 +109,15 @@ export function createLaneTextDeliverer(params: CreateLaneTextDelivererParams) {
     text: string;
     skipRegressive: "always" | "existingOnly";
     hadPreviewMessage: boolean;
-  }): boolean =>
-    Boolean(args.currentPreviewText) &&
-    args.currentPreviewText.startsWith(args.text) &&
-    args.text.length < args.currentPreviewText.length &&
-    (args.skipRegressive === "always" || args.hadPreviewMessage);
+  }): boolean => {
+    const currentPreviewText = args.currentPreviewText;
+    return (
+      currentPreviewText !== undefined &&
+      currentPreviewText.startsWith(args.text) &&
+      args.text.length < currentPreviewText.length &&
+      (args.skipRegressive === "always" || args.hadPreviewMessage)
+    );
+  };
 
   const tryEditPreviewMessage = async (args: {
     laneName: LaneName;