feat(appkit): agents() plugin, createAgent(def), and markdown-driven agents

CHANGELOG.md

@@ -8,6 +8,24 @@ All notable changes to this project will be documented in this file.
 
 # Changelog
 
+# Changelog
+
+# Changelog
+
+## [0.25.1](https://github.com/databricks/appkit/compare/v0.25.0...v0.25.1) (2026-04-27)
+
+### appkit
+
+* **appkit:** check isRetryable before retrying in interceptor ([#276](https://github.com/databricks/appkit/issues/276)) ([1c994a6](https://github.com/databricks/appkit/commit/1c994a6d99f397b56e90f1b53df06a61f02b9e82))
+
+
+## [0.25.0](https://github.com/databricks/appkit/compare/v0.24.0...v0.25.0) (2026-04-23)
+
+### files
+
+* **files:** per-volume in-app policy enforcement ([#197](https://github.com/databricks/appkit/issues/197)) ([f54dca5](https://github.com/databricks/appkit/commit/f54dca5da5af5368c7bcb18745715b54a99d47e9))
+
+
 ## [0.24.0](https://github.com/databricks/appkit/compare/v0.23.0...v0.24.0) (2026-04-20)
 
 * add AST extraction to serving type generator and move types to shared/ ([#279](https://github.com/databricks/appkit/issues/279)) ([422afb3](https://github.com/databricks/appkit/commit/422afb38aa73f8adb94e091225dc3381bd92cfcd))

apps/dev-playground/server/index.ts

@@ -50,7 +50,7 @@ const adminOnly: FilePolicy = (action, _resource, user) => {
 
 createApp({
   plugins: [
-    server({ autoStart: false }),
+    server(),
     reconnect(),
     telemetryExamples(),
     analytics({}),
@@ -95,9 +95,8 @@ createApp({
     // }),
   ],
   ...(process.env.APPKIT_E2E_TEST && { client: createMockClient() }),
-}).then((appkit) => {
-  appkit.server
-    .extend((app) => {
+  onPluginsReady(appkit) {
+    appkit.server.extend((app) => {
       app.get("/sp", (_req, res) => {
         appkit.analytics
           .query("SELECT * FROM samples.nyctaxi.trips;")
@@ -195,9 +194,9 @@ createApp({
           results,
         });
       });
-    })
-    .start();
-});
+    });
+  },
+}).catch(console.error);
 
 type ProbeResult = {
   volume: string;

apps/dev-playground/shared/appkit-types/analytics.d.ts

@@ -119,10 +119,10 @@ declare module "@databricks/appkit-ui/react" {
         result: Array<{
           /** @sqlType STRING */
           string_value: string;
-          /** @sqlType STRING */
-          number_value: string;
-          /** @sqlType STRING */
-          boolean_value: string;
+          /** @sqlType INT */
+          number_value: number;
+          /** @sqlType BOOLEAN */
+          boolean_value: boolean;
           /** @sqlType STRING */
           date_value: string;
           /** @sqlType STRING */

docs/docs/api/appkit/Class.ServerError.md

@@ -6,7 +6,6 @@ Use for server start/stop issues, configuration conflicts, etc.
 ## Example
 
 ```typescript
-throw new ServerError("Cannot get server when autoStart is true");
 throw new ServerError("Server not started");
 ```
 
@@ -151,26 +150,6 @@ Create a human-readable string representation
 
 ***
 
-### autoStartConflict()
-
-```ts
-static autoStartConflict(operation: string): ServerError;
-```
-
-Create a server error for autoStart conflict
-
-#### Parameters
-
-| Parameter | Type |
-| ------ | ------ |
-| `operation` | `string` |
-
-#### Returns
-
-`ServerError`
-
-***
-
 ### clientDirectoryNotFound()
 
 ```ts

docs/docs/api/appkit/Function.createApp.md

@@ -4,6 +4,7 @@
 function createApp<T>(config: {
   cache?: CacheConfig;
   client?: WorkspaceClient;
+  onPluginsReady?: (appkit: PluginMap<T>) => void | Promise<void>;
   plugins?: T;
   telemetry?: TelemetryConfig;
 }): Promise<PluginMap<T>>;
@@ -13,6 +14,9 @@ Bootstraps AppKit with the provided configuration.
 
 Initializes telemetry, cache, and service context, then registers plugins
 in phase order (core, normal, deferred) and awaits their setup.
+If a `onPluginsReady` callback is provided it runs after plugin setup but
+before the server starts, giving you access to the full appkit handle
+for registering custom routes or performing async setup.
 The returned object maps each plugin name to its `exports()` API,
 with an `asUser(req)` method for user-scoped execution.
 
@@ -26,9 +30,10 @@ with an `asUser(req)` method for user-scoped execution.
 
 | Parameter | Type |
 | ------ | ------ |
-| `config` | \{ `cache?`: [`CacheConfig`](Interface.CacheConfig.md); `client?`: `WorkspaceClient`; `plugins?`: `T`; `telemetry?`: [`TelemetryConfig`](Interface.TelemetryConfig.md); \} |
+| `config` | \{ `cache?`: [`CacheConfig`](Interface.CacheConfig.md); `client?`: `WorkspaceClient`; `onPluginsReady?`: (`appkit`: `PluginMap`\<`T`\>) => `void` \| `Promise`\<`void`\>; `plugins?`: `T`; `telemetry?`: [`TelemetryConfig`](Interface.TelemetryConfig.md); \} |
 | `config.cache?` | [`CacheConfig`](Interface.CacheConfig.md) |
 | `config.client?` | `WorkspaceClient` |
+| `config.onPluginsReady?` | (`appkit`: `PluginMap`\<`T`\>) => `void` \| `Promise`\<`void`\> |
 | `config.plugins?` | `T` |
 | `config.telemetry?` | [`TelemetryConfig`](Interface.TelemetryConfig.md) |
 
@@ -51,12 +56,12 @@ await createApp({
 ```ts
 import { createApp, server, analytics } from "@databricks/appkit";
 
-const appkit = await createApp({
-  plugins: [server({ autoStart: false }), analytics({})],
-});
-
-appkit.server.extend((app) => {
-  app.get("/custom", (_req, res) => res.json({ ok: true }));
+await createApp({
+  plugins: [server(), analytics({})],
+  onPluginsReady(appkit) {
+    appkit.server.extend((app) => {
+      app.get("/custom", (_req, res) => res.json({ ok: true }));
+    });
+  },
 });
-await appkit.server.start();
 ```

docs/docs/faq.md

@@ -16,7 +16,7 @@ AppKit provides built-in integrations with the following Databricks services via
 | [Lakebase](./plugins/lakebase) | Lakebase Autoscaling (PostgreSQL) | Relational database access via standard pg.Pool with automatic OAuth token refresh |
 | [Genie](./plugins/genie) | AI/BI Genie Spaces | Natural language data queries with conversation management and streaming |
 | [Files](./plugins/files) | Unity Catalog Volumes | Multi-volume file operations (list, read, upload, download, delete, preview) |
-| [Serving](./plugins/serving) | Model Serving | Authenticated proxy to Model Serving endpoints with invoke and streaming support |
+| [Model Serving](./plugins/model-serving) | Model Serving | Authenticated proxy to Model Serving endpoints with invoke and streaming support |
 | [Server](./plugins/server) | N/A | Express HTTP server with static file serving, Vite dev mode, and plugin route injection |
 
 Stay tuned for new plugins as we constantly expand integrations!

docs/docs/plugins/serving.md → docs/docs/plugins/model-serving.md

@@ -2,7 +2,7 @@
 sidebar_position: 7
 ---
 
-# Serving plugin
+# Model Serving plugin
 
 Provides an authenticated proxy to [Databricks Model Serving](https://docs.databricks.com/aws/en/machine-learning/model-serving) endpoints, with invoke and streaming support.
 

docs/docs/plugins/server.md

@@ -36,22 +36,38 @@ await createApp({
 });
 ```
 
-## Manual server start example
+## Custom routes example
 
-When you need to extend Express with custom routes:
+Use the `onPluginsReady` callback to extend Express with custom routes before the server starts:
 
 ```ts
 import { createApp, server } from "@databricks/appkit";
 
-const appkit = await createApp({
-  plugins: [server({ autoStart: false })],
+await createApp({
+  plugins: [server()],
+  onPluginsReady(appkit) {
+    appkit.server.extend((app) => {
+      app.get("/custom", (_req, res) => res.json({ ok: true }));
+    });
+  },
 });
+```
 
-appkit.server.extend((app) => {
-  app.get("/custom", (_req, res) => res.json({ ok: true }));
-});
+The `onPluginsReady` callback also supports async operations:
 
-await appkit.server.start();
+```ts
+await createApp({
+  plugins: [server()],
+  async onPluginsReady(appkit) {
+    const pool = await initializeDatabase();
+    appkit.server.extend((app) => {
+      app.get("/data", async (_req, res) => {
+        const result = await pool.query("SELECT 1");
+        res.json(result);
+      });
+    });
+  },
+});
 ```
 
 ## Configuration options
@@ -64,7 +80,6 @@ await createApp({
     server({
       port: 8000,          // default: Number(process.env.DATABRICKS_APP_PORT) || 8000
       host: "0.0.0.0",     // default: process.env.FLASK_RUN_HOST || "0.0.0.0"
-      autoStart: true,     // default: true
       staticPath: "dist",  // optional: force a specific static directory
     }),
   ],

knip.json

@@ -7,7 +7,9 @@
     "docs"
   ],
   "workspaces": {
-    "packages/appkit": {},
+    "packages/appkit": {
+      "ignoreDependencies": ["@langchain/core", "ai"]
+    },
     "packages/appkit-ui": {
       "ignoreDependencies": ["tailwindcss", "tw-animate-css"]
     }
@@ -17,6 +19,12 @@
     "**/*.example.tsx",
     "**/*.css",
     "packages/appkit/src/plugins/vector-search/**",
+    "packages/appkit/src/plugin/index.ts",
+    "packages/appkit/src/plugin/to-plugin.ts",
+    "packages/appkit/src/plugins/agents/index.ts",
+    "packages/appkit/src/plugins/agents/tools/index.ts",
+    "packages/appkit/src/plugins/agents/from-plugin.ts",
+    "packages/appkit/src/plugins/agents/load-agents.ts",
     "template/**",
     "tools/**",
     "docs/**"

packages/appkit-ui/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@databricks/appkit-ui",
   "type": "module",
-  "version": "0.24.0",
+  "version": "0.25.1",
   "license": "Apache-2.0",
   "repository": {
     "type": "git",

packages/appkit/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@databricks/appkit",
   "type": "module",
-  "version": "0.24.0",
+  "version": "0.25.1",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "packageManager": "pnpm@10.21.0",
@@ -29,6 +29,18 @@
       "development": "./src/index.ts",
       "default": "./dist/index.js"
     },
+    "./agents/vercel-ai": {
+      "development": "./src/agents/vercel-ai.ts",
+      "default": "./dist/agents/vercel-ai.js"
+    },
+    "./agents/langchain": {
+      "development": "./src/agents/langchain.ts",
+      "default": "./dist/agents/langchain.js"
+    },
+    "./agents/databricks": {
+      "development": "./src/agents/databricks.ts",
+      "default": "./dist/agents/databricks.js"
+    },
     "./type-generator": {
       "types": "./dist/type-generator/index.d.ts",
       "development": "./src/type-generator/index.ts",
@@ -71,20 +83,38 @@
     "@types/semver": "7.7.1",
     "dotenv": "16.6.1",
     "express": "4.22.0",
+    "js-yaml": "^4.1.1",
     "obug": "2.1.1",
     "pg": "8.18.0",
     "picocolors": "1.1.1",
     "semver": "7.7.3",
     "shared": "workspace:*",
     "vite": "npm:rolldown-vite@7.1.14",
-    "ws": "8.18.3"
+    "ws": "8.18.3",
+    "zod": "^4.0.0"
+  },
+  "peerDependencies": {
+    "@langchain/core": ">=0.3.0",
+    "ai": ">=4.0.0"
+  },
+  "peerDependenciesMeta": {
+    "ai": {
+      "optional": true
+    },
+    "@langchain/core": {
+      "optional": true
+    }
   },
   "devDependencies": {
+    "@ai-sdk/openai": "4.0.0-beta.27",
+    "@langchain/core": "^1.1.39",
     "@types/express": "4.17.25",
+    "@types/js-yaml": "^4.0.9",
     "@types/json-schema": "7.0.15",
     "@types/pg": "8.16.0",
     "@types/ws": "8.18.1",
-    "@vitejs/plugin-react": "5.1.1"
+    "@vitejs/plugin-react": "5.1.1",
+    "ai": "7.0.0-beta.76"
   },
   "overrides": {
     "vite": "npm:rolldown-vite@7.1.14"
@@ -93,6 +123,9 @@
   "publishConfig": {
     "exports": {
       ".": "./dist/index.js",
+      "./agents/vercel-ai": "./dist/agents/vercel-ai.js",
+      "./agents/langchain": "./dist/agents/langchain.js",
+      "./agents/databricks": "./dist/agents/databricks.js",
       "./dist/shared/src/plugin": "./dist/shared/src/plugin.d.ts",
       "./type-generator": "./dist/type-generator/index.js",
       "./package.json": "./package.json"