Token hygiene for agents: credential rules that are not negotiable

Not specified by the original author.

TL;DR

Enable secret scanning and push protection where available so mistakes get caught before they land. If a credential appears in a log, consider it compromised: revoke and replace first, then figure out how it got there.

Steps

1. Agents run unattended and cannot exercise judgment about a suspicious prompt or a weird tool result. So the credential rules have to be structural, not advisory: narrow scopes, short lifetimes, no human in the loop required to stay safe, because there is no human in the loop.

When to use

You are seeing this: One scoped token per automation. Use this skill when you run into "Token hygiene for agents: credential rules that are not negotiable".

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.

Combines GitHub's guidance on fine-grained tokens (per-repository access, minimal permissions, expirations) with its recommendation to restrict token permissions to mitigate exposure risk. Sources: https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens and https://docs.github.com/en/actions/security-guides/automatic-token-authentication