AWS Signature Version 4 (SigV4)

SigV4 signing is like a wax seal stamped on an envelope. If the seal is intact, the recipient can confirm the letter really came from that person and that its contents weren't changed along the way. Similarly, SigV4 attaches this kind of mark to every request sent to Amazon's servers, letting the server verify that "this request really came from the sender it claims, and nothing was altered in transit."

This mark is a value freshly calculated each time by combining a temporarily issued key with the contents of the request, so it can't easily be copied and reused for a different request. That means even when a program sends requests on someone's behalf without a human logging in directly, going through this process lets the server confidently verify who the actual owner of that request is.

The article mentions this in the phrase "signed with SigV4 using temporary credentials before being sent to the CloudWatch OTLP endpoint." It means that when a coding agent's usage logs are sent to Amazon's servers, this signing process is used to prove that the data genuinely came from an authenticated organization. It's important not to confuse SigV4 with encryption that hides the content of data — it's a signing process that proves "who sent it," not a way to conceal what was sent.