[nest] Add NestJS support on Vercel

.changeset/nest-vercel-build-output.md

@@ -0,0 +1,5 @@
+---
+'@workflow/nest': patch
+---
+
+Add `buildVercelOutput()` to `NestLocalBuilder` for generating Vercel Build Output API functions with `experimentalTriggers`, enabling VQS consumer discovery for NestJS deployments

docs/content/docs/getting-started/nestjs.mdx

@@ -323,12 +323,68 @@ WorkflowModule.forRoot({
 });
 ```
 
-## Deploying to production
-
-Workflow DevKit apps currently work best when deployed to [Vercel](https://vercel.com/home) and needs no special configuration.
+## Deploying to Vercel
 
 <FluidComputeCallout />
 
+### 1. Create the Vercel entry point
+
+Create a `_vercel/entry.js` file that exports your NestJS app as a serverless function handler. Use `_vercel/` instead of `api/` to avoid triggering Vercel's automatic serverless function detection which conflicts with the Build Output API:
+
+{/*@skip-typecheck - Shows Vercel entry point*/}
+
+```javascript title="_vercel/entry.js" lineNumbers
+import { createApp } from '../dist/app.js';
+
+let ready;
+async function createHandler() {
+  const { app } = await createApp();
+  return app.getHttpAdapter().getInstance();
+}
+
+export default async (req, res) => {
+  ready ??= createHandler();
+  return (await ready)(req, res);
+};
+```
+
+<Callout>
+Your main app module should export a `createApp()` function that creates and initializes the NestJS application, returning both the app instance and the underlying HTTP adapter.
+</Callout>
+
+### 2. Add the build step
+
+Add `workflow-nest build` as a postbuild script. This builds workflow bundles locally, and on Vercel it additionally generates the [Build Output API](https://vercel.com/docs/build-output-api/v3) with the queue triggers that VQS needs to call back your workflow functions:
+
+```json title="package.json" lineNumbers
+{
+  "scripts": {
+    "prebuild": "npx @workflow/nest init --force",
+    "build": "nest build",
+    "postbuild": "workflow-nest build",
+    "start:dev": "npx @workflow/nest init --force && nest start --watch"
+  }
+}
+```
+
+The `workflow-nest build` command auto-detects the `api/index.js` entry point. To specify a different path, use `workflow-nest build --entry path/to/entry.js`.
+
+### 3. Configure Vercel project
+
+Set your Vercel project's **Framework Preset** to **Other** (not "NestJS"). The NestJS preset uses `@vercel/node` which conflicts with the Build Output API that `workflow-nest build` generates.
+
+Your `vercel.json` only needs the build command:
+
+```json title="vercel.json" lineNumbers
+{
+  "buildCommand": "pnpm build"
+}
+```
+
+<Callout type="warning">
+Do **not** set the framework preset to "NestJS" and do not add `functions`, `outputDirectory`, or `rewrites` to `vercel.json` — routing is handled by the generated Build Output API.
+</Callout>
+
 Check the [Deploying](/docs/deploying) section to learn how your workflows can be deployed elsewhere.
 
 ## Next Steps

packages/nest/README.md

@@ -125,14 +125,61 @@ WorkflowModule.forRoot({
 });
 ```
 
+## Deploying to Vercel
+
+### 1. Create an entry point
+
+Create `_vercel/entry.js` exporting your NestJS app as a handler (use `_vercel/` not `api/` to avoid triggering Vercel's automatic function detection):
+
+```javascript
+// _vercel/entry.js
+import { createApp } from '../dist/app.js';
+
+let ready;
+async function createHandler() {
+  const { app } = await createApp();
+  return app.getHttpAdapter().getInstance();
+}
+
+export default async (req, res) => {
+  ready ??= createHandler();
+  return (await ready)(req, res);
+};
+```
+
+### 2. Add postbuild script
+
+```json
+{
+  "scripts": {
+    "prebuild": "npx @workflow/nest init --force",
+    "build": "nest build",
+    "postbuild": "workflow-nest build"
+  }
+}
+```
+
+`workflow-nest build` builds workflow bundles and, when running on Vercel, generates the [Build Output API](https://vercel.com/docs/build-output-api/v3) with queue triggers so VQS can discover your workflow consumers. The `api/index.js` entry point is auto-detected.
+
+### 3. Configure Vercel project
+
+Set the Framework Preset to **Other** (not "NestJS") — the NestJS preset conflicts with the Build Output API.
+
+```json
+{ "buildCommand": "pnpm build" }
+```
+
+Do **not** add `functions`, `outputDirectory`, or `rewrites` — the Build Output API handles routing.
+
 ## How It Works
 
 The `@workflow/nest` package provides:
 
 1. **WorkflowModule** - A NestJS module that handles workflow bundle building and HTTP routing
 2. **WorkflowController** - Handles workflow and step execution requests at `.well-known/workflow/v1/`
 3. **NestLocalBuilder** - Builds workflow bundles (steps.mjs, workflows.mjs) from your source files
-4. **CLI** - Generates `.swcrc` configuration with the SWC plugin properly resolved
+4. **NestLocalBuilder.buildVercelOutput()** - Generates Vercel Build Output API
+5. **CLI** - Generates `.swcrc` configuration with the SWC plugin properly resolved
 
 ## Why the CLI?
 
@@ -178,17 +225,43 @@ WorkflowModule.forRoot({
 })
 ```
 
+### NestLocalBuilder.buildVercelOutput(options)
+
+Generates the Vercel Build Output API.
+
+{/*@skip-typecheck: Shows buildVercelOutput options*/}
+
+```typescript
+await builder.buildVercelOutput({
+  // Path to your Vercel serverless function entry point (required)
+  entryPoint: 'api/index.js',
+
+  // Max duration in seconds for the NestJS function (default: 300)
+  maxDuration: 300,
+
+  // Additional routes for the Build Output API config.json
+  additionalRoutes: [],
+});
+```
+
+This generates:
+
+- `.vercel/output/functions/.well-known/workflow/v1/step.func/` with `experimentalTriggers`
+- `.vercel/output/functions/.well-known/workflow/v1/flow.func/` with `experimentalTriggers`
+- `.vercel/output/functions/.well-known/workflow/v1/webhook/[token].func/`
+- `.vercel/output/functions/api/index.js.func/` (bundled NestJS app)
+- `.vercel/output/config.json` with routing rules
+
 ### CLI Commands
 
 ```bash
 # Generate .swcrc configuration
 npx @workflow/nest init
+npx @workflow/nest init --force  # overwrite existing
 
-# Force regenerate (overwrites existing)
-npx @workflow/nest init --force
-
-# Show help
-npx @workflow/nest --help
+# Build workflow bundles (+ Vercel Build Output API when VERCEL is set)
+npx @workflow/nest build
+npx @workflow/nest build --entry api/handler.js  # custom entry point
 ```
 
 ## License