Hi Appian,
In our middleware server’s integration solution, we are calling an Appian Web API but receiving a 400 error.
However, when we test the same Appian Web API call using curl from the middleware server, it works fine with a 200 response.
Since there seems to be no difference between the two calls, I’m not sure why the 400 error occurs.
If you have had a similar experience and resolved it, I would appreciate your advice.
Thank you
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Most common causes for your 400 error when curl works:Header differences -> Your middleware might be sending Content-Type: application/json; charset=utf-8 while curl sends just application/json. Try removing charset specification.Request body encoding -> Check for extra whitespace, BOM characters, or different JSON formatting between your middleware and curl requests.To debug precisely, capture the exact request from your middleware and compare it byte-by-byte with the working curl request.