Tinyproxy may be traditionally thought of as more of a server-side tool, but it's also great for local development where you might use MITM proxy or ModHeaders etc¹.

Here's a minimal (or tiny...) config for tinyproxy to serve as a starting point:

User tinyproxy
Group tinyproxy
Port 8888
LogLevel Info
DisableViaHeader Yes
MaxClients 100
StartServers 1

ReverseOnly Yes
ReversePath "/" "http://some-host.com"
ReverseBaseURL "http://localhost:8888"
upstream http some-host:80
AddHeader "Authorization" "Basic add-auth-header-here-if-needed"

In this example were just proxying all requests on localhost:8888 to some-host.com.

So if the API your trying to hit is some-host.com/api/endpoint instead you could hit localhost:8888/api/endpoint. Also we're adding in the Authorization header.

Save the above snippet as tiny.conf and use it like:

tinyproxy -dc tiny.conf