Sample Catalog

Every sample is a self-contained workspace under sample/. None call a real model provider — all use a mock model, so no API keys are needed.

Sample	AI SDK call	What it proves
00-showcase	streamText (mock)	Guard, Zod pipe, interceptor, and exception filter all composing around @AiStream on Express
01-fastify-parity	streamText (mock)	One controller on Express and Fastify; streamed payloads match byte-for-byte
02-abort-signal	streamText + @AiAbortSignal (mock)	Disconnect mid-stream cancels the AI SDK call on both adapters
03-error-mapping	streamText (mock)	Pre-stream HTTP errors vs in-stream onError frame mapping on both adapters
04-stream-object	streamObject (mock)	Structured object streamed as partial-JSON text deltas via format: 'text' on both adapters
05-stream-ui	createUIMessageStream (mock)	Custom data-* UI parts — the v5 generative-UI equivalent of streamUI — on both adapters
06-migration	streamText / createUIMessageStream (mock)	Cookbook @Res() vs @AiStream before/after: byte-identical streams, plus pre-stream validation and Fastify parity the @Res() recipe lacks
07-tool-context	streamText + tool + @AiContext (mock)	A tool's execute reads the guard-attached user via @AiContext mid-stream on both adapters

00-showcase

The full integration baseline. One controller wires all four enhancer types around @AiStream: an API-key guard (pre-stream 401/403), a Zod validation pipe (pre-stream 400), a request-audit interceptor, and an exception filter. Its smoke test asserts each enhancer behaves correctly and the stream flows.

Never simplified for brevity — its richness is the proof of integration depth.

01-fastify-parity

Mounts one controller (guard + Zod pipe + exception filter) on both an Express app and a Fastify app. The smoke test boots both adapters and asserts the streamed payloads are identical. See Adapters.

02-abort-signal

Opens a stream with a client-side AbortController, disconnects mid-stream, and asserts the AI SDK model call is cancelled — on both Express and Fastify. See @AiAbortSignal.

03-error-mapping

Demonstrates the two-sided error model: pre-stream errors (guard/pipe/handler) become HTTP errors, while in-stream failures become documented stream error frames. The default onError hides the raw error; a custom mapper rewrites it. Verified on both adapters. See Error Mapping.

04-stream-object

Serves a streamObject result through @AiStream({ format: 'text' }), streaming a structured object as partial-JSON text deltas on both adapters. See Stream Formats.

05-stream-ui

The v5 generative-UI replacement for the removed RSC streamUI: a UI message stream with a custom data-* part built via createUIMessageStream, served through @AiStream on both adapters using a small app-owned wrapper. See Stream Formats.

06-migration

A before/after port of the official AI SDK NestJS cookbook recipe. The /legacy/* routes are the raw @Res() + pipe*ToResponse recipe; the /migrated/* routes are the @AiStream version. The smoke test asserts the streams are byte-identical, that the migrated route validates input as a pre-stream 400 where the legacy recipe 500s, and that the migrated recipes stream on Fastify where the Express-only @Res() recipe cannot. See the Migration Guide.

07-tool-context

An API-key guard authenticates the caller pre-stream and attaches request.user. A streamText tool's execute then reads that user back through the @AiContext() value the handler captured — proving a tool can reach request-scoped data even though it runs mid-stream, after the handler returned. The smoke test asserts a missing key is a pre-stream 401 and that the tool output carries the authenticated user on both adapters. See @AiContext.