Get HTTP Header

The Get HTTP Header block reads one header from the request that started the flow, like Authorization or User-Agent, and passes its value to the next block.

When to use it

• Read an API key or token that the caller sent.
• Check what kind of client is calling, with User-Agent or Accept-Language.
• Don't use it for data in the URL. Use Get HTTP Param for that.
• Don't use it for data in the body. Use Get HTTP Request Body.
• Don't use it for cookies. Use Get Request Cookie.

Inputs

Field	Required	Default	What it does
Mode	No	Single	Single handles one value. Multiple handles a list of rows, see below.
Name	Yes	none	The header to read. Can be a JS expression. Capital letters don't matter: Authorization and authorization are the same header.

Outputs

Handle	When it is used
Next (right)	Always. The next block receives the header's value as text.

Example

The caller sent Authorization: Bearer abc123.

Field	Value
Name	Authorization

The next block receives "Bearer abc123" as its input.

Single or Multiple

Pick Multiple to read several headers in one block. Each row has a Name.

• The output is an array with one value per row, in row order.
• A missing header gives "" for its row. The other rows still work.

With rows Authorization and User-Agent, the next block receives something like ["Bearer abc123", "curl/8.4.0"].

How it behaves

• A missing header is empty text. If the caller didn't send it, the value is "". It is not an error. Check it with an If Condition using Is Empty/Null.
• It replaces the flowing data. The next block's input is the header value, not what came before. To keep earlier data, store it first with Set Variable.
• Read-only. It never changes the request.

Related blocks

• Get Request Cookie: read a cookie instead.
• Get HTTP Param: read a query or path value.
• Set HTTP Header: add a header to the response.
• If Condition: react to a missing or wrong value.