diff --git a/ui/src/lib/api.ts b/ui/src/lib/api.ts
new file mode 100644
index 0000000..7c97d9e
--- /dev/null
+++ b/ui/src/lib/api.ts
@@ -0,0 +1,122 @@
+import { CreateInstanceOptions, Instance } from "@/types/instance"
+
+const API_BASE = '/api/v1'
+
+// Configuration for API calls
+interface ApiConfig {
+  apiKey?: string
+}
+
+// Global config - can be updated when auth is added
+let apiConfig: ApiConfig = {}
+
+export const setApiConfig = (config: ApiConfig) => {
+  apiConfig = config
+}
+
+// Base API call function with error handling
+async function apiCall<T>(
+  endpoint: string,
+  options: RequestInit = {}
+): Promise<T> {
+  const url = `${API_BASE}${endpoint}`
+  
+  // Prepare headers
+  const headers: HeadersInit = {
+    'Content-Type': 'application/json',
+    ...options.headers,
+  }
+  
+  // Add API key - not supported yet
+  // if (apiConfig.apiKey) {
+  //   headers['Authorization'] = `Bearer ${apiConfig.apiKey}`
+  // }
+  
+  try {
+    const response = await fetch(url, {
+      ...options,
+      headers,
+    })
+    
+    if (!response.ok) {
+      // Try to get error message from response
+      let errorMessage = `HTTP ${response.status}`
+      try {
+        const errorText = await response.text()
+        if (errorText) {
+          errorMessage += `: ${errorText}`
+        }
+      } catch {
+        // If we can't read the error, just use status
+      }
+      
+      throw new Error(errorMessage)
+    }
+    
+    // Handle empty responses (like DELETE)
+    if (response.status === 204) {
+      return undefined as T
+    }
+    
+    const data = await response.json()
+    return data
+  } catch (error) {
+    if (error instanceof Error) {
+      throw error
+    }
+    throw new Error('Network error occurred')
+  }
+}
+
+// Instance API functions
+export const instancesApi = {
+  // GET /instances
+  list: () => apiCall<Instance[]>('/instances'),
+  
+  // GET /instances/{name}
+  get: (name: string) => apiCall<Instance>(`/instances/${name}`),
+  
+  // POST /instances/{name}
+  create: (name: string, options: CreateInstanceOptions) =>
+    apiCall<Instance>(`/instances/${name}`, {
+      method: 'POST',
+      body: JSON.stringify(options),
+    }),
+  
+  // PUT /instances/{name}
+  update: (name: string, options: CreateInstanceOptions) =>
+    apiCall<Instance>(`/instances/${name}`, {
+      method: 'PUT',
+      body: JSON.stringify(options),
+    }),
+  
+  // DELETE /instances/{name}
+  delete: (name: string) =>
+    apiCall<void>(`/instances/${name}`, {
+      method: 'DELETE',
+    }),
+  
+  // POST /instances/{name}/start
+  start: (name: string) =>
+    apiCall<Instance>(`/instances/${name}/start`, {
+      method: 'POST',
+    }),
+  
+  // POST /instances/{name}/stop
+  stop: (name: string) =>
+    apiCall<Instance>(`/instances/${name}/stop`, {
+      method: 'POST',
+    }),
+  
+  // POST /instances/{name}/restart
+  restart: (name: string) =>
+    apiCall<Instance>(`/instances/${name}/restart`, {
+      method: 'POST',
+    }),
+  
+  // GET /instances/{name}/logs
+  getLogs: (name: string, lines?: number) => {
+    const params = lines ? `?lines=${lines}` : ''
+    return apiCall<string>(`/instances/${name}/logs${params}`)
+  },
+}
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