Headers

Overview

Header helpers live in fusion-core and are exposed as:

Language	Module
Python	`from fusion_framework import header` (or `fusion_framework.header`)
TypeScript / Node	`import { header } from "fusion-framework"`
C#	`Header` static helpers / constants on `FusionFramework`

Use them when building response envelopes:

return self.response(
    body,
    status=status.HTTP_SUCCESS,
    headers=header.download("report.csv", header.TEXT_CSV),
)

Fingerprint headers

When fingerprinting is enabled (fingerprint.enabled, default true), responses can include:

Constant	Typical value
`X_POWERED_BY`	`Fusion Framework` (`FRAMEWORK_POWERED_BY`)
`X_FRAMEWORK`	`Fusion` (`FRAMEWORK_ID`)
`X_FUSION_VERSION`	current framework version string

Helper builders

Helper	Result
`attachment(filename)`	`Content-Disposition: attachment; filename=…`
`inline(filename?)`	`Content-Disposition: inline…`
`content_type(media_type, charset?)`	`Content-Type` map
`location(url)`	`Location` map
`cache_control(value)`	`Cache-Control` map
`download(filename, media_type?)`	attachment + `Content-Type` (default `application/octet-stream`)

Filenames are basenamed (path stripped) and escaped to avoid header injection.

Header name constants

Constant	Header name
`ACCEPT`	`Accept`
`ACCEPT_ENCODING`	`Accept-Encoding`
`ACCEPT_LANGUAGE`	`Accept-Language`
`AUTHORIZATION`	`Authorization`
`CACHE_CONTROL`	`Cache-Control`
`CONNECTION`	`Connection`
`CONTENT_DISPOSITION`	`Content-Disposition`
`CONTENT_ENCODING`	`Content-Encoding`
`CONTENT_LENGTH`	`Content-Length`
`CONTENT_RANGE`	`Content-Range`
`CONTENT_TYPE`	`Content-Type`
`COOKIE`	`Cookie`
`DATE`	`Date`
`ETAG`	`ETag`
`EXPECT`	`Expect`
`EXPIRES`	`Expires`
`HOST`	`Host`
`IF_MATCH`	`If-Match`
`IF_MODIFIED_SINCE`	`If-Modified-Since`
`IF_NONE_MATCH`	`If-None-Match`
`IF_RANGE`	`If-Range`
`IF_UNMODIFIED_SINCE`	`If-Unmodified-Since`
`LAST_MODIFIED`	`Last-Modified`
`LOCATION`	`Location`
`ORIGIN`	`Origin`
`PRAGMA`	`Pragma`
`RANGE`	`Range`
`REFERER`	`Referer`
`RETRY_AFTER`	`Retry-After`
`SERVER`	`Server`
`SET_COOKIE`	`Set-Cookie`
`TE`	`TE`
`TRAILER`	`Trailer`
`TRANSFER_ENCODING`	`Transfer-Encoding`
`UPGRADE`	`Upgrade`
`USER_AGENT`	`User-Agent`
`VARY`	`Vary`
`VIA`	`Via`
`WARNING`	`Warning`
`WWW_AUTHENTICATE`	`WWW-Authenticate`
`X_CONTENT_TYPE_OPTIONS`	`X-Content-Type-Options`
`X_FRAME_OPTIONS`	`X-Frame-Options`
`X_REQUESTED_WITH`	`X-Requested-With`
`X_FORWARDED_FOR`	`X-Forwarded-For`
`X_FORWARDED_PROTO`	`X-Forwarded-Proto`
`X_REAL_IP`	`X-Real-IP`
`ACCESS_CONTROL_ALLOW_ORIGIN`	`Access-Control-Allow-Origin`
`ACCESS_CONTROL_ALLOW_METHODS`	`Access-Control-Allow-Methods`
`ACCESS_CONTROL_ALLOW_HEADERS`	`Access-Control-Allow-Headers`
`ACCESS_CONTROL_ALLOW_CREDENTIALS`	`Access-Control-Allow-Credentials`
`ACCESS_CONTROL_EXPOSE_HEADERS`	`Access-Control-Expose-Headers`
`ACCESS_CONTROL_MAX_AGE`	`Access-Control-Max-Age`
`ACCESS_CONTROL_REQUEST_METHOD`	`Access-Control-Request-Method`
`ACCESS_CONTROL_REQUEST_HEADERS`	`Access-Control-Request-Headers`
`X_POWERED_BY`	`X-Powered-By`
`X_FRAMEWORK`	`X-Framework`
`X_FUSION_VERSION`	`X-Fusion-Version`

Media-type / value constants

Also on the same header surface (and HTTP_HEADER_CONSTANTS):

Constant	Value
`APPLICATION_JSON`	`application/json`
`APPLICATION_JSON_UTF8`	`application/json; charset=utf-8`
`APPLICATION_OCTET_STREAM`	`application/octet-stream`
`APPLICATION_PDF`	`application/pdf`
`APPLICATION_XML`	`application/xml`
`APPLICATION_FORM_URLENCODED`	`application/x-www-form-urlencoded`
`MULTIPART_FORM_DATA`	`multipart/form-data`
`TEXT_PLAIN`	`text/plain`
`TEXT_PLAIN_UTF8`	`text/plain; charset=utf-8`
`TEXT_HTML`	`text/html`
`TEXT_HTML_UTF8`	`text/html; charset=utf-8`
`TEXT_CSS`	`text/css`
`TEXT_CSV`	`text/csv`
`TEXT_JAVASCRIPT`	`text/javascript`
`IMAGE_PNG`	`image/png`
`IMAGE_JPEG`	`image/jpeg`
`IMAGE_GIF`	`image/gif`
`IMAGE_WEBP`	`image/webp`
`IMAGE_SVG`	`image/svg+xml`

Constant	Value
`FRAMEWORK_POWERED_BY`	`Fusion Framework`
`FRAMEWORK_ID`	`Fusion`

Source: crates/fusion-core/src/headers.rs.