Request lifecycle

Pipeline

sequenceDiagram
  participant C as Client
  participant H as Hyper fusion-core
  participant G as Global middleware
  participant R as Route middleware
  participant A as Handler

  C->>H: HTTP request
  H->>H: Parse method path headers body params query
  H->>G: request dict/object
  G->>R: call_next
  R->>A: call_next
  A-->>R: response envelope
  R-->>G: response envelope
  G-->>H: response envelope
  H-->>C: HTTP response

Request fields

Field	Meaning
`method`	HTTP verb
`path`	Request path
`headers`	Header map
`body`	Raw body string
`params`	Path parameters
`query`	Query string map
`state`	Mutable bag for middleware (e.g. JWT)

Response envelope

Handlers return (or middleware short-circuits with) an object shaped like:

{ "status": 200, "body": { }, "headers": { } }

Use self.response(...) / Response(...) helpers. Non-string bodies are JSON-serialized by the core when appropriate.

Middleware order

Global middleware registered on FusionApp (outer first)
Route middleware from @route(..., middleware=...) / roles=...
Handler

Returning { "status": …, "body": … } stops the chain.

On Python only, handler signature parameters are filled from path → body (for write methods) → query. This is not a dependency-injection container. Node and C# expose params / query / body on the request object instead.

Fingerprint headers

When enabled, Fusion may attach identity headers such as X-Powered-By, X-Framework, and X-Fusion-Version (middleware and/or server layer depending on binding and fingerprint.enabled). See language middleware guides.