Framework Adapters

InferDI adapters connect exact container types to framework lifecycle boundaries. HTTP adapters create one request scope and expose it at the framework-native location. The React adapter provides typed contexts and can own a client-created child scope.

Adapters manage request-scope lifecycle. The core package stays zero-dependency and does not add decorators, controller scanning, handler parameter injection, or route discovery.

Packages

Package	Framework	Scope location	Root-only mode
@inferdi/fastify	Fastify v5	request.di	yes
@inferdi/hono	Hono v4	c.var.di	no
@inferdi/koa	Koa v3	ctx.state.di	no
@inferdi/express	Express 5	req.di	no
@inferdi/elysia	Elysia v1	context.di	yes
@inferdi/react	React 19	React context	external Provider

React uses a component lifecycle rather than the request lifecycle below. Its external Provider never disposes its container; its managed ScopeProvider creates after commit and always disposes its child scope. See the React adapter.

Common Lifecycle Contract

In scoped mode every adapter runs the same steps for each request:

1. Create the scope from the root container (createScope, default root.createScope()) when the request begins.
2. Expose it at the framework-native location. Hono, Koa, Express, and Elysia expose it before setup. Fastify exposes request.di after setup succeeds and only exposes it temporarily while cleaning up a setup failure. Cleanup hooks still observe the public slot; error handlers never receive a half-built scope.
3. Set up the scope with setupScope when additional initialization is needed before handlers run. It may be async.
4. Handle the request: route handlers and the framework's error handlers resolve services from the exposed scope.
5. Dispose the scope at the framework's safe completion point (disposeScope, default scope.dispose()), unless ownership was transferred.

Shared options

Option	Default	Purpose
container	required	Root container exposed to the app. Adapters never dispose it (except Fastify's opt-in disposeRootOnClose).
createScope	root.createScope()	Build the per-request scope. Pass declared request inputs here. May be async.
setupScope	none	Run additional initialization before handlers. May be async.
disposeScope	scope.dispose()	Custom teardown. May be sync or async.
autoDispose	true	false, or a predicate returning false, hands disposal to your code.
onDisposeError	per-adapter sink	Receives request-scope disposal failures: Fastify request.log.error, Koa ctx.app.emit('error'), others console.error.
skipInferdiDispose(...)	—	Marks one request as application-owned for streaming or background work.

Error and ownership rules

• Setup failure surfaces only the original error. If setupScope throws, the adapter disposes the half-built scope and re-raises that error. A teardown failure during this cleanup goes to onDisposeError (or the sink) and is never aggregated into the surfaced error.
• A failed request still disposes. skipInferdiDispose suppresses cleanup only on a successful response; an error path disposes regardless. Express is the exception — its callback middleware cannot observe a handled route error, so a skipped failed Express request stays application-owned.
• autoDispose: false and skipInferdiDispose transfer ownership. Your code then owns disposing the scope at the correct framework boundary.
• Cleanup errors after a response is produced are routed to the sink and swallowed. The response is already sent, so a late teardown failure can never corrupt it.

Important Differences

Adapter	Difference
Fastify	Disposes in onResponse; abort cleanup uses onRequestAbort; root disposal can be opted into with disposeRootOnClose.
Hono	Disposes after await next(); streaming helpers can return before stream work finishes, so streaming routes often need skipInferdiDispose.
Koa	Waits for Node response finish or close, so normal stream bodies do not need a skip.
Express	Cannot detect a handled downstream route error from callback middleware; a skipped failed request remains application-owned.
Elysia	Cleanup is bound to onAfterResponse; if that hook is never reached, resources held by the scope cannot be released by the adapter.