feat: add watch flag

README.md

@@ -221,10 +221,31 @@ codegen init
 ## Generate
 With your configuration file in hand, time to generate the code and use it! This can be done manually or integrate into your build process. Checkout [all the examples](./examples/) for inspiration on how to do it.
 
+### Basic Generation
 ```sh
+# Generate code once
 codegen generate
+
+# Generate with specific config file
+codegen generate ./my-config.js
+```
+
+### Watch Mode (Development)
+For development workflows, use watch mode to automatically regenerate code when your input files change:
+
+```sh
+# Watch for changes in the input file specified in your config
+codegen generate --watch
+
+# Watch for changes in a specific file or directory
+codegen generate --watch --watchPath ./asyncapi
+
+# Short form
+codegen generate -w -p ./schemas/
 ```
 
+Watch mode is perfect for development environments where you want your generated code to stay in sync with your API specifications as you make changes.
+
 # 👀 Goals
 Besides the [milestones](https://github.com/the-codegen-project/cli/milestones), we have certain goals that we want to reach for various reasons;
 - [ ] ⭐ Reach 50 stars - So we can publish the CLI on Brew and Chocolatey

docs/getting-started.md

@@ -148,7 +148,29 @@ Customize it to your heart's desire! [Each generator has unique set of options](
 ## Integrate
 With your configuration file in hand, time to integrate it into your project and generate some code!  Checkout [all the integrations](../examples/) for inspiration how to do it.
 
-Or manually generate some code;
+### Generate Code
+
+#### One-time Generation
 ```sh
+# Generate code once
 codegen generate
+
+# Generate with specific config file
+codegen generate ./my-config.js
 ```
+
+#### Development with Watch Mode
+For active development, use watch mode to automatically regenerate code when your input files change:
+
+```sh
+# Watch for changes in the input file specified in your config
+codegen generate --watch
+
+# Watch for changes in a specific file or directory
+codegen generate --watch --watchPath ./my-asyncapi.yaml
+
+# Short form
+codegen generate -w -p ./schemas/
+```
+
+**Pro tip:** Use watch mode during development to keep your generated code in sync with your API specifications. Press `Ctrl+C` to stop watching.

docs/usage.md

@@ -9,7 +9,7 @@ $ npm install -g @the-codegen-project/cli
 $ codegen COMMAND
 running command...
 $ codegen (--version)
-@the-codegen-project/cli/0.52.0 linux-x64 node-v18.20.8
+@the-codegen-project/cli/0.52.0 darwin-arm64 node-v22.19.0
 $ codegen --help [COMMAND]
 USAGE
   $ codegen COMMAND
@@ -69,13 +69,16 @@ Generate code based on your configuration, use `init` to get started.
 
 ```
 USAGE
-  $ codegen generate [FILE] [--help]
+  $ codegen generate [FILE] [--help] [-w] [-p <value>]
 
 ARGUMENTS
   FILE  Path or URL to the configuration file, defaults to root of where the command is run
 
 FLAGS
-  --help  Show CLI help.
+  -p, --watchPath=<value>  Optional path to watch for changes when --watch flag is used. If not provided, watches the
+                           input file from configuration
+  -w, --watch              Watch for file changes and regenerate code automatically
+      --help               Show CLI help.
 
 DESCRIPTION
   Generate code based on your configuration, use `init` to get started.

examples/README.md

@@ -13,11 +13,19 @@ An example demonstrating integration with Next.js applications.
 ### [E-commerce AsyncAPI Payload](./ecommerce-asyncapi-payload/)
 A comprehensive example showing how to generate TypeScript payload models from AsyncAPI specifications for an e-commerce order processing system.
 
+### [E-commerce AsyncAPI Parameters](./ecommerce-asyncapi-parameters/)
+A comprehensive example showing how to generate TypeScript parameter models from AsyncAPI specifications for dynamic channel routing in an e-commerce messaging system.
+
 ### [E-commerce AsyncAPI Headers](./ecommerce-asyncapi-headers/)
 A comprehensive example showing how to generate TypeScript header models from AsyncAPI specifications for an e-commerce messaging system, covering authentication, tracing, routing, and metadata management.
 
-### [E-commerce AsyncAPI types](./ecommerce-asyncapi-types/)
+### [E-commerce AsyncAPI Channels](./ecommerce-asyncapi-channels/)
+A focused example showing how to generate protocol-specific messaging functions from AsyncAPI specifications for order lifecycle management in an e-commerce system.
+
+### [E-commerce AsyncAPI Client](./ecommerce-asyncapi-client/)
+An example demonstrating how to generate complete, type-safe client SDKs for NATS messaging with order lifecycle management, including connection management and JetStream integration.
 
+### [E-commerce AsyncAPI Types](./ecommerce-asyncapi-types/)
 A comprehensive example showing how to generate TypeScript types from AsyncAPI specifications for an e-commerce messaging system.
 
 ## Getting Started
@@ -28,4 +36,21 @@ A comprehensive example showing how to generate TypeScript types from AsyncAPI s
 4. Run the generator
 5. Integrate the generated code into your application
 
+## Development Workflow
+
+For active development, most examples include watch mode scripts for automatic code regeneration:
+
+```bash
+# For TypeScript Library example
+npm run dev
+
+# For Next.js example  
+npm run generate:watch
+
+# Or use the CLI directly
+codegen generate --watch
+```
+
+Watch mode automatically regenerates your code when input files change, keeping your generated code in sync during development.
+
 For more detailed information, see the [documentation](https://the-codegen-project.org/docs/).

examples/typescript-library/package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "build": "npm run generate",
     "start": "ts-node src/index.ts",
-    "generate": "codegen generate"
+    "generate": "codegen generate",
+    "dev": "codegen generate --watch"
   },
   "license": "Apache-2.0",
   "devDependencies": {

examples/typescript-nextjs/package.json

@@ -8,7 +8,8 @@
     "build": "npm run generate && next build",
     "start": "next start",
     "lint": "next lint",
-    "generate": "codegen generate"
+    "generate": "codegen generate",
+    "generate:watch": "codegen generate --watch"
   },
   "dependencies": {
     "@t3-oss/env-nextjs": "^0.10.1",

package.json

@@ -19,6 +19,7 @@
     "@oclif/plugin-help": "^6.0.21",
     "@oclif/plugin-version": "^2.0.17",
     "@readme/openapi-parser": "^5.0.1",
+    "chokidar": "^4.0.3",
     "cosmiconfig": "^9.0.0",
     "graphology": "^0.26.0",
     "inquirer": "^8.2.6",

src/codegen/generators/typescript/channels/asyncapi.ts

@@ -11,7 +11,9 @@ import {
   TypeScriptChannelRenderedFunctionType,
   SupportedProtocols,
   TypeScriptChannelsContext,
-  TypeScriptChannelsGeneratorContext
+  TypeScriptChannelsGeneratorContext,
+  sendingFunctionTypes,
+  receivingFunctionTypes
 } from './types';
 import {findNameFromChannel} from '../../../utils';
 import {ConstrainedObjectModel, OutputModel} from '@asyncapi/modelina';
@@ -24,30 +26,6 @@ import {generatehttpChannels} from './protocols/http';
 import {generateWebSocketChannels} from './protocols/websocket';
 
 type Action = 'send' | 'receive' | 'subscribe' | 'publish';
-const sendingFunctionTypes = [
-  ChannelFunctionTypes.NATS_JETSTREAM_PUBLISH,
-  ChannelFunctionTypes.NATS_PUBLISH,
-  ChannelFunctionTypes.NATS_REQUEST,
-  ChannelFunctionTypes.MQTT_PUBLISH,
-  ChannelFunctionTypes.KAFKA_PUBLISH,
-  ChannelFunctionTypes.AMQP_EXCHANGE_PUBLISH,
-  ChannelFunctionTypes.AMQP_QUEUE_PUBLISH,
-  ChannelFunctionTypes.EVENT_SOURCE_EXPRESS,
-  ChannelFunctionTypes.HTTP_CLIENT,
-  ChannelFunctionTypes.WEBSOCKET_PUBLISH,
-  ChannelFunctionTypes.WEBSOCKET_REGISTER
-];
-const receivingFunctionTypes = [
-  ChannelFunctionTypes.NATS_JETSTREAM_PULL_SUBSCRIBE,
-  ChannelFunctionTypes.NATS_JETSTREAM_PUSH_SUBSCRIBE,
-  ChannelFunctionTypes.NATS_REPLY,
-  ChannelFunctionTypes.NATS_SUBSCRIBE,
-  ChannelFunctionTypes.MQTT_SUBSCRIBE,
-  ChannelFunctionTypes.KAFKA_SUBSCRIBE,
-  ChannelFunctionTypes.EVENT_SOURCE_FETCH,
-  ChannelFunctionTypes.AMQP_QUEUE_SUBSCRIBE,
-  ChannelFunctionTypes.WEBSOCKET_SUBSCRIBE
-];
 
 // eslint-disable-next-line sonarjs/cognitive-complexity
 export function shouldRenderFunctionType(

src/codegen/generators/typescript/channels/types.ts

@@ -29,6 +29,32 @@ export enum ChannelFunctionTypes {
   WEBSOCKET_REGISTER = 'websocket_register'
 }
 
+export const sendingFunctionTypes = [
+  ChannelFunctionTypes.NATS_JETSTREAM_PUBLISH,
+  ChannelFunctionTypes.NATS_PUBLISH,
+  ChannelFunctionTypes.NATS_REQUEST,
+  ChannelFunctionTypes.MQTT_PUBLISH,
+  ChannelFunctionTypes.KAFKA_PUBLISH,
+  ChannelFunctionTypes.AMQP_EXCHANGE_PUBLISH,
+  ChannelFunctionTypes.AMQP_QUEUE_PUBLISH,
+  ChannelFunctionTypes.EVENT_SOURCE_EXPRESS,
+  ChannelFunctionTypes.HTTP_CLIENT,
+  ChannelFunctionTypes.WEBSOCKET_PUBLISH,
+  ChannelFunctionTypes.WEBSOCKET_REGISTER
+];
+
+export const receivingFunctionTypes = [
+  ChannelFunctionTypes.NATS_JETSTREAM_PULL_SUBSCRIBE,
+  ChannelFunctionTypes.NATS_JETSTREAM_PUSH_SUBSCRIBE,
+  ChannelFunctionTypes.NATS_REPLY,
+  ChannelFunctionTypes.NATS_SUBSCRIBE,
+  ChannelFunctionTypes.MQTT_SUBSCRIBE,
+  ChannelFunctionTypes.KAFKA_SUBSCRIBE,
+  ChannelFunctionTypes.EVENT_SOURCE_FETCH,
+  ChannelFunctionTypes.AMQP_QUEUE_SUBSCRIBE,
+  ChannelFunctionTypes.WEBSOCKET_SUBSCRIBE
+];
+
 export const zodTypescriptChannelsGenerator = z.object({
   id: z.string().optional().default('channels-typescript'),
   dependencies: z