app.compiler

Append builtin middleware (static, safe_target, sse_lifecycle, etc.) to list.

Build router from pending routes.

Raise if any pending route starts with a framework-reserved URL prefix.

The block-fetch dispatcher owns/_frag/**— a user route like /_frag/customwould either shadow the dispatcher or be shadowed by it, and there's no policy where that ambiguity is a good idea. Fail fast with a message that points the user at what to change.

Raise if a user route collides with Chirp-owned internal URL space.

ResolveSessionConfig.secure ("auto"-> bool) at freeze, by env.

secure defaults to the string "auto", which means "Secure in production/staging, off in local dev". The store readscfg.secureand passes it straight towith_cookie (typed bool), so the string must be resolved to a concrete bool before any request runs. Doing it at freeze keeps resolution deterministic and statically checkable, and uses config.env— the single posture signal — exactly like the secret_key env gate and the security-stack severity matrix.

Detection is by class name (type(mw).__name__), mirroring the contracts layer, so a SessionMiddleware is found without importing it here purely for an isinstance check. The actual resolution is delegated to the middleware'sresolve_secure, which also resolves the store's inner config (the two-config pattern).

Check that middleware dependencies are satisfied.

CSRFMiddleware requires SessionMiddleware to wrap it (i.e. Session must be registered before CSRF in add_middleware calls). Detects the mis-ordering early at freeze time rather than waiting for a request to fail.

Compiles app setup state into immutable runtime state.