expressjs.com/_includes/api/en/4x/express.raw.md

express.raw([options])

This middleware is available in Express v4.17.0 onwards.

This is a built-in middleware function in Express. It parses incoming request payloads into a Buffer and is based on body-parser.

Returns middleware that parses all bodies as a Buffer and only looks at requests where the Content-Type header matches the type option. This parser accepts any Unicode encoding of the body and supports automatic inflation of gzip and deflate encodings.

A new body Buffer containing the parsed data is populated on the request object after the middleware (i.e. req.body), or an empty object ({}) if there was no body to parse, the Content-Type was not matched, or an error occurred.

As `req.body`'s shape is based on user-controlled input, all properties and values in this object are untrusted and should be validated before trusting. For example, `req.body.toString()` may fail in multiple ways, for example stacking multiple parsers `req.body` may be from a different parser. Testing that `req.body` is a `Buffer` before calling buffer methods is recommended.

The following table describes the properties of the optional options object.

Property	Description	Type	Default
inflate	Enables or disables handling deflated (compressed) bodies; when disabled, deflated bodies are rejected.	Boolean	true
limit	Controls the maximum request body size. If this is a number, then the value specifies the number of bytes; if it is a string, the value is passed to the bytes library for parsing.	Mixed	"100kb"
type	This is used to determine what media type the middleware will parse. This option can be a string, array of strings, or a function. If not a function, type option is passed directly to the type-is library and this can be an extension name (like bin), a mime type (like application/octet-stream), or a mime type with a wildcard (like */* or application/*). If a function, the type option is called as fn(req) and the request is parsed if it returns a truthy value.	Mixed	"application/octet-stream"
verify	This option, if supplied, is called as verify(req, res, buf, encoding), where buf is a Buffer of the raw request body and encoding is the encoding of the request. The parsing can be aborted by throwing an error.	Function	undefined