diff --git a/src/plugins/plugins.ts b/src/plugins/plugins.ts
new file mode 100644
index 0000000..875a71e
--- /dev/null
+++ b/src/plugins/plugins.ts
@@ -0,0 +1,11 @@
+
+import { anyDict } from '../types/index.d'
+import BrowsePlugin from '../plugins/browse'
+import TavilyPlugin from '../plugins/tavily'
+import PythonPlugin from '../plugins/python'
+
+export const availablePlugins: anyDict = {
+  browse: BrowsePlugin, 
+  python:  PythonPlugin,
+  tavily: TavilyPlugin,
+}
diff --git a/src/plugins/python.ts b/src/plugins/python.ts
index 44dca6a..76eaa9f 100644
--- a/src/plugins/python.ts
+++ b/src/plugins/python.ts
@@ -10,7 +10,7 @@ export default class extends Plugin {
   }
 
   isEnabled(): boolean {
-    return this.config.enabled && this.config.binpath
+    return this.config.enabled && this.config.binpath != null
   }
 
   getName(): string {
diff --git a/src/plugins/tavily.ts b/src/plugins/tavily.ts
index a3218e9..3862dbc 100644
--- a/src/plugins/tavily.ts
+++ b/src/plugins/tavily.ts
@@ -12,7 +12,7 @@ export default class extends Plugin {
   }
 
   isEnabled(): boolean {
-    return this.config.enabled && this.config.apiKey
+    return this.config.enabled && this.config.apiKey != null
   }
 
   getName(): string {
diff --git a/src/services/engine.ts b/src/services/engine.ts
index 4c501cc..bf0a2d3 100644
--- a/src/services/engine.ts
+++ b/src/services/engine.ts
@@ -4,18 +4,10 @@ import { LlmResponse, LlmCompletionOpts, LLmCompletionPayload, LlmStream, LlmChu
 import { Configuration, Model } from '../types/config.d'
 import { getFileContents } from './download'
 import Plugin from '../plugins/plugin'
-import BrowsePlugin from '../plugins/browse'
-import TavilyPlugin from '../plugins/tavily'
-import PythonPlugin from '../plugins/python'
+import { availablePlugins } from '../plugins/plugins'
 import { PluginParameter } from '../types/plugin.d'
 import { minimatch } from 'minimatch'
 
-export const availablePlugins: anyDict = {
-  browse: BrowsePlugin, 
-  python:  PythonPlugin,
-  tavily: TavilyPlugin,
-}
-
 export default class LlmEngine {
 
   config: Configuration
diff --git a/src/settings/SettingsPlugins.vue b/src/settings/SettingsPlugins.vue
index 2417d0c..7231746 100644
--- a/src/settings/SettingsPlugins.vue
+++ b/src/settings/SettingsPlugins.vue
@@ -17,7 +17,7 @@
 <script setup>
 
 import { ref, computed, nextTick } from 'vue'
-import { availablePlugins } from '../services/engine'
+import { availablePlugins } from '../plugins/plugins'
 import SettingsBrowse from './SettingsBrowse.vue'
 import SettingsPython from './SettingsPython.vue'
 import SettingsTavily from './SettingsTavily.vue'
diff --git a/tests/mocks/plugins.ts b/tests/mocks/plugins.ts
new file mode 100644
index 0000000..e469baf
--- /dev/null
+++ b/tests/mocks/plugins.ts
@@ -0,0 +1,88 @@
+
+import Plugin from '../../src/plugins/plugin'
+
+export class Plugin1 extends Plugin {
+  
+  isEnabled(): boolean {
+    return true
+  }
+
+  getName(): string {
+    return 'plugin1'
+  }
+
+  getDescription(): string {
+    return 'Plugin 1'
+  }
+
+  getRunningDescription(): string {
+    return 'run1'
+  }
+
+  getParameters(): any[] {
+    return []
+  }
+
+  async execute(parameters: any): Promise<any> {
+    return 'result1'
+  }
+}
+
+export class Plugin2 extends Plugin {
+
+  isEnabled(): boolean {
+    return true
+  }
+
+  getName(): string {
+    return 'plugin2'
+  }
+
+  getDescription(): string {
+    return 'Plugin 2'
+  }
+
+  getPreparationDescription(): string {
+    return 'prep2'
+  }
+
+  getRunningDescription(): string {
+    return 'run2'
+  }
+
+  getParameters(): any[] {
+    return [
+      {
+        name: 'param1',
+        type: 'string',
+        description: 'Parameter 1',
+        required: true
+      },
+      {
+        name: 'param2',
+        type: 'number',
+        description: 'Parameter 2',
+        required: false
+      }
+    ]
+  }
+
+  async execute(parameters: any): Promise<any> {
+    return parameters
+  }
+}
+
+export class Plugin3 extends Plugin {
+
+  getName(): string {
+    return 'plugin3'
+  }
+
+  getDescription(): string {
+    return 'Plugin 3'
+  }
+
+  getParameters(): any[] {
+    return []
+  }
+}
diff --git a/tests/unit/engine_plugins.test.ts b/tests/unit/engine_plugins.test.ts
index 3dd01df..52327b6 100644
--- a/tests/unit/engine_plugins.test.ts
+++ b/tests/unit/engine_plugins.test.ts
@@ -1,8 +1,22 @@
 
-import { beforeEach, expect, test } from 'vitest'
+import { vi, beforeEach, expect, test } from 'vitest'
 import { store } from '../../src/services/store'
 import defaults from '../../defaults/settings.json'
-import OpenAI from '../../src/services/openai'
+import Browse from '../../src/plugins/browse'
+import Tavily from '../../src/plugins/tavily'
+import Python from '../../src/plugins/python'
+
+vi.mock('../../src/vendor/tavily', async () => {
+  const Tavily = vi.fn()
+  Tavily.prototype.search = vi.fn(() => ({ results: [ 'page1' ] }))
+  return { default: Tavily }
+})
+
+window.api = {
+  interpreter: {
+    python: vi.fn(() => ({ result: ['bonjour'] }))
+  }
+}
 
 beforeEach(() => {
   store.config = defaults
@@ -20,62 +34,45 @@ beforeEach(() => {
   }
 })
 
-test('OpenAI Functions', () => {
-  const llm = new OpenAI(store.config)
-  expect(llm.getAvailableTools()).toStrictEqual([
-    {
-      type: 'function',
-      function: {
-        name: 'get_html_as_text',
-        description: 'Download an HTML page and return the text content',
-        parameters: {
-          type: 'object',
-          properties: {
-            'url': {
-              type: 'string',
-              'enum': undefined,
-              description: 'The URL of the page to download',
-            }
-          },
-          required: ['url'],
-        },
-      },
-    },
-    {
-      type: 'function',
-      function: {
-        name: 'run_python_code',
-        description: 'Execute Python code and return the result',
-        parameters: {
-          type: 'object',
-          properties: {
-            'script': {
-              type: 'string',
-              'enum': undefined,
-              description: 'The script to run',
-            }
-          },
-          required: ['script'],
-        },
-      },
-    },
-    {
-      type: 'function',
-      function: {
-        name: 'search_tavily',
-        description: 'This tool allows you to search the web for information on a given topic',
-        parameters: {
-          type: 'object',
-          properties: {
-            'query': {
-              type: 'string',
-              'enum': undefined,
-              description: 'The query to search for',
-            }
-          },
-          required: ['query'],
-        },
-      },
-    },
-  ])
+test('Browse Plugin', async () => {
+  const browse = new Browse(store.config.plugins.browse)
+  expect(browse.isEnabled()).toBe(true)
+  expect(browse.getName()).toBe('get_html_as_text')
+  expect(browse.getDescription()).not.toBeFalsy()
+  expect(browse.getPreparationDescription()).toBeFalsy()
+  expect(browse.getRunningDescription()).not.toBeFalsy()
+  expect(browse.getParameters()[0].name).toBe('url')
+  expect(browse.getParameters()[0].type).toBe('string')
+  expect(browse.getParameters()[0].description).not.toBeFalsy()
+  expect(browse.getParameters()[0].required).toBe(true)
+  expect(await browse.execute({ url: 'https://google.com' })).toHaveProperty('content')
+})
+
+test('Tavily Plugin', async () => {
+  const tavily = new Tavily(store.config.plugins.tavily)
+  expect(tavily.isEnabled()).toBe(true)
+  expect(tavily.getName()).toBe('search_tavily')
+  expect(tavily.getDescription()).not.toBeFalsy()
+  expect(tavily.getPreparationDescription()).toBeFalsy()
+  expect(tavily.getRunningDescription()).not.toBeFalsy()
+  expect(tavily.getParameters()[0].name).toBe('query')
+  expect(tavily.getParameters()[0].type).toBe('string')
+  expect(tavily.getParameters()[0].description).not.toBeFalsy()
+  expect(tavily.getParameters()[0].required).toBe(true)
+  expect(await tavily.execute({ query: 'test' })).toHaveProperty('results')
+})
+
+test('Python Plugin', async () => {
+  const python = new Python(store.config.plugins.python)
+  expect(python.isEnabled()).toBe(true)
+  expect(python.getName()).toBe('run_python_code')
+  expect(python.getDescription()).not.toBeFalsy()
+  expect(python.getPreparationDescription()).not.toBeFalsy()
+  expect(python.getRunningDescription()).not.toBeFalsy()
+  expect(python.getParameters()[0].name).toBe('script')
+  expect(python.getParameters()[0].type).toBe('string')
+  expect(python.getParameters()[0].description).not.toBeFalsy()
+  expect(python.getParameters()[0].required).toBe(true)
+  expect(await python.execute({ script: 'print("hello")' })).toHaveProperty('result')
+  expect((await python.execute({ script: 'print("hello")' })).result).toBe('bonjour')
 })
diff --git a/tests/unit/engine_plugins_mocked.test.ts b/tests/unit/engine_plugins_mocked.test.ts
new file mode 100644
index 0000000..e1069da
--- /dev/null
+++ b/tests/unit/engine_plugins_mocked.test.ts
@@ -0,0 +1,76 @@
+
+import { vi, beforeEach, expect, test } from 'vitest'
+import { Plugin1, Plugin2, Plugin3 } from '../mocks/plugins'
+import OpenAI from '../../src/services/openai'
+import { store } from '../../src/services/store'
+import defaults from '../../defaults/settings.json'
+
+vi.mock('../../src/plugins/plugins', async () => {
+  return {
+    availablePlugins: {
+      plugin1: Plugin1,
+      plugin2: Plugin2,
+      plugin3: Plugin3,
+    }
+  }
+})
+
+beforeEach(() => {
+  store.config = defaults
+  store.config.llm.engine = 'mock'
+})
+
+test('Engine plugin descriptions', () => {
+  const llm = new OpenAI(store.config)
+  expect(llm.getToolPreparationDescription('plugin1')).toBeNull()
+  expect(llm.getToolRunningDescription('plugin1')).toBe('run1')
+  expect(llm.getToolPreparationDescription('plugin2')).toBe('prep2')
+  expect(llm.getToolRunningDescription('plugin2')).toBe('run2')
+})
+
+test('Engine plugin execution', async () => {
+  const llm = new OpenAI(store.config)
+  expect(await llm.callTool('plugin1', {})).toStrictEqual('result1')
+  expect(await llm.callTool('plugin2', { param1: 'a', param2: 1 })).toStrictEqual({ param1: 'a', param2: 1 })
+})
+
+test('OpenAI Functions', () => {
+  const llm = new OpenAI(store.config)
+  expect(llm.getAvailableTools()).toStrictEqual([
+    {
+      type: 'function',
+      function: {
+        name: 'plugin1',
+        description: 'Plugin 1',
+        parameters: {
+          type: 'object',
+          properties: { },
+          required: [],
+        },
+      },
+    },
+    {
+      type: 'function',
+      function: {
+        name: 'plugin2',
+        description: 'Plugin 2',
+        parameters: {
+          type: 'object',
+          properties: {
+            'param1': {
+              type: 'string',
+              'enum': undefined,
+              description: 'Parameter 1',
+            },
+            'param2': {
+              type: 'number',
+              'enum': undefined,
+              description: 'Parameter 2',
+            },
+          },
+          required: ['param1'],
+        },
+      },
+    },
+  ])
+})