diff --git a/apps/server/src/services/llm/providers/anthropic.ts b/apps/server/src/services/llm/providers/anthropic.ts
index 48a06bbc4e..aef87f8258 100644
--- a/apps/server/src/services/llm/providers/anthropic.ts
+++ b/apps/server/src/services/llm/providers/anthropic.ts
@@ -113,9 +113,13 @@ export class AnthropicProvider extends BaseProvider {
         for (let i = 0; i < chatMessages.length; i++) {
             const m = chatMessages[i];
             const isLastBeforeNewTurn = i === chatMessages.length - 2;
+            // Anthropic rejects empty text content blocks. Replace empty
+            // content (e.g. tool-only assistant turns) with a placeholder
+            // to preserve conversation flow.
+            const content = m.content || "(tool use)";
             coreMessages.push({
                 role: m.role as "user" | "assistant",
-                content: m.content,
+                content,
                 ...(isLastBeforeNewTurn && { providerOptions: CACHE_CONTROL })
             });
         }
@@ -132,7 +136,7 @@ export class AnthropicProvider extends BaseProvider {
         }
 
         const systemPrompt = this.buildSystemPrompt(messages, config);
-        const chatMessages = messages.filter(m => m.role !== "system" && m.content);
+        const chatMessages = messages.filter(m => m.role !== "system");
         const coreMessages = this.buildMessages(chatMessages, systemPrompt);
 
         const thinkingBudget = config.thinkingBudget || 10000;
diff --git a/apps/server/src/services/llm/providers/base_provider.ts b/apps/server/src/services/llm/providers/base_provider.ts
index ca975fa895..fda95856c3 100644
--- a/apps/server/src/services/llm/providers/base_provider.ts
+++ b/apps/server/src/services/llm/providers/base_provider.ts
@@ -144,7 +144,7 @@ export abstract class BaseProvider implements LlmProvider {
 
     chat(messages: LlmMessage[], config: LlmProviderConfig): StreamResult {
         const systemPrompt = this.buildSystemPrompt(messages, config);
-        const chatMessages = messages.filter(m => m.role !== "system" && m.content);
+        const chatMessages = messages.filter(m => m.role !== "system");
         const coreMessages = this.buildMessages(chatMessages, systemPrompt);
 
         const streamOptions: Parameters<typeof streamText>[0] = {
diff --git a/apps/server/src/services/llm/providers/google.ts b/apps/server/src/services/llm/providers/google.ts
index 0902986d10..e33b1bccca 100644
--- a/apps/server/src/services/llm/providers/google.ts
+++ b/apps/server/src/services/llm/providers/google.ts
@@ -15,14 +15,14 @@ const { models: AVAILABLE_MODELS, pricing: MODEL_PRICING } = buildModelList([
         id: "gemini-2.5-pro",
         name: "Gemini 2.5 Pro",
         pricing: { input: 1.25, output: 10 },
-        contextWindow: 1048576,
-        isDefault: true
+        contextWindow: 1048576
     },
     {
         id: "gemini-2.5-flash",
         name: "Gemini 2.5 Flash",
         pricing: { input: 0.3, output: 2.5 },
-        contextWindow: 1048576
+        contextWindow: 1048576,
+        isDefault: true
     },
     {
         id: "gemini-2.5-flash-lite",
diff --git a/apps/server/src/services/llm/skills/index.ts b/apps/server/src/services/llm/skills/index.ts
index ff22097111..a38ee13a81 100644
--- a/apps/server/src/services/llm/skills/index.ts
+++ b/apps/server/src/services/llm/skills/index.ts
@@ -5,7 +5,7 @@
  */
 
 import { tool } from "ai";
-import { readFileSync } from "fs";
+import { readFile } from "fs/promises";
 import { dirname, join } from "path";
 import { fileURLToPath } from "url";
 import { z } from "zod";
@@ -36,12 +36,12 @@ const SKILLS: SkillDefinition[] = [
     }
 ];
 
-function loadSkillContent(name: string): string | null {
+async function loadSkillContent(name: string): Promise<string | null> {
     const skill = SKILLS.find((s) => s.name === name);
     if (!skill) {
         return null;
     }
-    return readFileSync(join(__dirname, skill.file), "utf-8");
+    return readFile(join(__dirname, skill.file), "utf-8");
 }
 
 /**
@@ -63,7 +63,7 @@ export const loadSkill = tool({
         name: z.string().describe("The skill name to load")
     }),
     execute: async ({ name }) => {
-        const content = loadSkillContent(name);
+        const content = await loadSkillContent(name);
         if (!content) {
             return { error: `Unknown skill: '${name}'. Available: ${SKILLS.map((s) => s.name).join(", ")}` };
         }