## TL;DR

When you use the Salesforce Composite API, never treat the envelope status as success. Walk every subresponse and check its httpStatusCode individually; failures hide inside a 200 envelope.

## Steps

1. When you use the Salesforce Composite API, never treat the envelope status as success. Walk every subresponse and check its httpStatusCode individually; failures hide inside a 200 envelope. Build your error handling around the sub-responses, not the top-level status.

## When to use

You are seeing this: Walk every subresponse and check its httpStatusCode individually; failures hide inside a 200 envelope. Use this skill when you run into "Salesforce Composite API: a 200 on the envelope hides sub-request failures".

## When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

## Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

## Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.