diff --git a/packages/agent/src/core/toolAgent/toolAgentCore.ts b/packages/agent/src/core/toolAgent/toolAgentCore.ts
index a472f07..f05fdba 100644
--- a/packages/agent/src/core/toolAgent/toolAgentCore.ts
+++ b/packages/agent/src/core/toolAgent/toolAgentCore.ts
@@ -1,7 +1,5 @@
 import { CoreMessage, ToolSet, generateText, tool as makeTool } from 'ai';
 
-import { getAnthropicApiKeyError } from '../../utils/errors.js';
-
 import { DEFAULT_CONFIG } from './config.js';
 import {
   addCacheControlToMessages,
@@ -30,9 +28,6 @@ export const toolAgent = async (
 
   let interactions = 0;
 
-  const apiKey = process.env.ANTHROPIC_API_KEY;
-  if (!apiKey) throw new Error(getAnthropicApiKeyError());
-
   const messages: CoreMessage[] = [
     {
       role: 'user',
diff --git a/packages/agent/src/utils/errors.ts b/packages/agent/src/utils/errors.ts
index f1960ea..5751c44 100644
--- a/packages/agent/src/utils/errors.ts
+++ b/packages/agent/src/utils/errors.ts
@@ -1,10 +1,65 @@
-export const getAnthropicApiKeyError = () => `
-Error: ANTHROPIC_API_KEY environment variable is not set
+// Provider configuration map
+export const providerConfig: Record<
+  string,
+  { keyName: string; docsUrl: string } | undefined
+> = {
+  anthropic: {
+    keyName: 'ANTHROPIC_API_KEY',
+    docsUrl: 'https://mycoder.ai/docs/getting-started/anthropic',
+  },
+  openai: {
+    keyName: 'OPENAI_API_KEY',
+    docsUrl: 'https://mycoder.ai/docs/getting-started/openai',
+  },
+  xai: {
+    keyName: 'XAI_API_KEY',
+    docsUrl: 'https://mycoder.ai/docs/getting-started/xai',
+  },
+  mistral: {
+    keyName: 'MISTRAL_API_KEY',
+    docsUrl: 'https://mycoder.ai/docs/getting-started/mistral',
+  },
+  // No API key needed for ollama as it uses a local server
+  ollama: undefined,
+};
 
-Before using MyCoder, you must have an ANTHROPIC_API_KEY specified either:
+/**
+ * Generates a provider-specific API key error message
+ * @param provider The LLM provider name
+ * @returns Error message with provider-specific instructions
+ */
+export const getProviderApiKeyError = (provider: string): string => {
+  const config = providerConfig[provider];
 
-- As an environment variable, "export ANTHROPIC_API_KEY=[your-api-key]" or
+  if (!config) {
+    return `Unknown provider: ${provider}`;
+  }
+
+  const { keyName, docsUrl } = config;
+  const platform = process.platform;
+  let osSpecificInstructions = '';
+
+  if (platform === 'win32') {
+    osSpecificInstructions = `- Using the windows command prompt, "setx ${keyName}=[your-api-key]"`;
+  } else if (platform === 'darwin' || platform === 'linux') {
+    osSpecificInstructions = `- As an environment variable, "export ${keyName}=[your-api-key]"`;
+  } else {
+    osSpecificInstructions = `- As an environment variable (platform-specific command)`;
+  }
+
+  return `
+Error: ${keyName} environment variable is not set
+
+Before using MyCoder with ${provider} models, you must have a ${keyName} specified.
+
+You can set it via:
+${osSpecificInstructions}
 - In a .env file in the folder you run "mycoder" from
 
-Get an API key from https://www.anthropic.com/api
+For setup instructions, visit: ${docsUrl}
 `;
+};
+
+// Legacy function for backward compatibility
+export const getAnthropicApiKeyError = () =>
+  getProviderApiKeyError('anthropic');
diff --git a/packages/cli/src/commands/$default.ts b/packages/cli/src/commands/$default.ts
index 0530f34..0dff70b 100644
--- a/packages/cli/src/commands/$default.ts
+++ b/packages/cli/src/commands/$default.ts
@@ -6,7 +6,8 @@ import {
   toolAgent,
   Logger,
   getTools,
-  getAnthropicApiKeyError,
+  getProviderApiKeyError,
+  providerConfig,
   userPrompt,
   LogLevel,
   subAgentTool,
@@ -95,33 +96,17 @@ export const command: CommandModule<SharedOptions, DefaultArgs> = {
       const userModelName = argv.modelName || userConfig.modelName;
 
       // Early API key check based on model provider
-      if (userModelProvider === 'anthropic' && !process.env.ANTHROPIC_API_KEY) {
-        logger.error(getAnthropicApiKeyError());
-        throw new Error('Anthropic API key not found');
-      } else if (
-        userModelProvider === 'openai' &&
-        !process.env.OPENAI_API_KEY
-      ) {
-        logger.error(
-          'No OpenAI API key found. Please set the OPENAI_API_KEY environment variable.',
-          'You can get an API key from https://platform.openai.com/api-keys',
-        );
-        throw new Error('OpenAI API key not found');
-      } else if (userModelProvider === 'xai' && !process.env.XAI_API_KEY) {
-        logger.error(
-          'No xAI API key found. Please set the XAI_API_KEY environment variable.',
-          'You can get an API key from https://platform.xai.com',
-        );
-        throw new Error('xAI API key not found');
-      } else if (
-        userModelProvider === 'mistral' &&
-        !process.env.MISTRAL_API_KEY
-      ) {
-        logger.error(
-          'No Mistral API key found. Please set the MISTRAL_API_KEY environment variable.',
-          'You can get an API key from https://console.mistral.ai/api-keys/',
-        );
-        throw new Error('Mistral API key not found');
+      const providerSettings =
+        providerConfig[userModelProvider as keyof typeof providerConfig];
+
+      if (providerSettings) {
+        const { keyName } = providerSettings;
+        const apiKey = process.env[keyName];
+
+        if (!apiKey) {
+          logger.error(getProviderApiKeyError(userModelProvider));
+          throw new Error(`${userModelProvider} API key not found`);
+        }
       }
       // No API key check needed for Ollama as it uses a local server