FAQ¶

Can handlers be sync?¶

Yes. Handlers, authenticate, and middleware hooks may all be def or async def — jero detects which at wiring. Use sync for pure CPU-light work; anything that does I/O should be async.

Does jero support WebSockets?¶

Yes—jero provides typed bidirectional WebSockets and an in-process typed Channel for fan-out. For one-way server push, prefer NDJSON or Server-Sent Events, which cover most live-update cases and give SSE clients automatic reconnection.

Can I serve static files?¶

No. jero serves JSON APIs; put assets on your reverse proxy or CDN (see Deployment). The one exception is the docs-page favicon, precomputed at wiring.

Where is `request.state`?¶

There isn't one. Middleware can't pass state to handlers — the idiom is jero's typed sources: bind the header in the handler, or carry the value on the auth user.

Can I return a `dict`?¶

No — a JSON body is a Struct (or list[Struct]), and a dict return is a WiringError at startup. The Struct is what buys validation, the OpenAPI schema, and msgspec's encode speed. See Philosophy.

Can I use Pydantic models?¶

Not on the wire — request and response contracts are msgspec Structs. Off the wire, anything goes: the demo app uses pydantic-settings to parse environment configuration, then maps it into a Struct.

Does it run on Python 3.12?¶

No. jero's generics use PEP 696 type-parameter defaults, which shipped in 3.13. See Getting started.

Why is there no dependency-injection container?¶

Because constructors already are one: build objects in wire, pass them in. The framework adds only what plain Python lacks — resource lifecycle. See Wiring & lifecycle and Philosophy.

You don't — each worker process runs wire and holds its own services and background queue. Shared state (a cache, a durable queue) belongs in an external service. See Deployment.

Why is the `TestClient` sync?¶

So plain pytest functions work with no async plumbing: it runs the app's full lifespan on a background event loop and gives you a requests-style API. See Testing.