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STANDARD STARTER CONTRACT / malformed-request

Malformed request

The server cannot process the request because its syntax or framing is invalid.

HTTP 400

Canonical type URI

https://errors.ctrlbox.dev/problems/malformed-request

This stable URI identifies the problem type, not a particular occurrence.

Possible causes

  • The JSON body is not well formed.

What to do next

  • Check request syntax and send a corrected request.

HTTP response contract

Set the actual HTTP status to 400 and Content-Type: application/problem+json. The JSON status below must agree with the actual response status.

RFC-defined members

type
The canonical URI above; clients use it as the primary problem identifier.
title
Malformed request — a stable human-readable summary (localization is permitted).
status
400 — advisory in the body; it does not set the HTTP status.
detail
A safe explanation specific to this occurrence. Clients should not parse it for machine decisions.
instance
An optional URI reference identifying a specific occurrence. It need not resolve; avoid sensitive identifiers.

These five members are defined by RFC 9457. This template includes type, title, status, and detail in its samples; RFC 9457 does not require all five.

Custom extension fields

This definition declares no custom extensions.

Extensions belong to this type’s contract. Consumers must ignore extensions they do not recognize.

Example response body

Illustrative occurrence data. Construct the response manually in your application or automation.

Example

{
  "type": "https://errors.ctrlbox.dev/problems/malformed-request",
  "title": "Malformed request",
  "status": 400,
  "detail": "The server cannot process the request because its syntax or framing is invalid."
}

Keep established public type URIs stable. The names here are template conventions, not an RFC catalogue. Read the response guide for manual setup and standards references.