Secret Scanners Look for Credentials. I Wanted One That Looks for Me.

I let coding agents write a lot of my commits now. They write what they see, and what they see is my machine: /Users/<me>/... in a README, me@my-laptop ~ % in a pasted test log, a claude.ai/code/session_... link at the bottom of a PR body.

None of that is a credential, so secret scanners don't flag it. I wanted one that knows who I am.

• Source: https://github.com/0-draft/kwangmyong
• Install: go install github.com/0-draft/kwangmyong/cmd/kwangmyong@latest, or a binary from the releases page

Same repository, two scanners

A four-commit repository for a made-up developer, Taro Yamada (login tyamada, laptop Taros-MacBook-Pro):

• README.md mentions /Users/tyamada/src/app/log
• NOTES.md mentions ~/.claude/projects/-Users-tyamada-src-app/memory
• test.log has tyamada@Taros-MacBook-Pro app % make test
• one commit message ends with a Claude Code session URL
• AUTHORS with 山田 太郎 was added in one commit and deleted in the next

gitleaks 8.30.1:

$ gitleaks git . --no-banner
INF 3 commits scanned.
INF scanned ~204 bytes (204 bytes) in 36.2ms
INF no leaks found

Correct. There are no secrets in it.

kwangmyong, given the name, login and hostname:

$ kwangmyong scan --history .
HIGH  identity.name              file NOTES.md:1            ty…[b35fc2ee]
HIGH  identity.name              file README.md:3           ty…[b35fc2ee]
HIGH  identity.name              file test.log:1            ty…[b35fc2ee]
HIGH  identity.host              file test.log:1            Ta…[a84654fa]
HIGH  generic.agent-session-url  commit 871e593 message     ht…[509ace00]
HIGH  identity.name              history AUTHORS@686ce61:1  山…[ed6d53c9]

6 findings (6 high, 0 warn)

Values are printed as a prefix and a fingerprint, so the scan log doesn't leak them again. --reveal prints them.

What it searches for

# ~/.config/kwangmyong/config.toml
[identity]
names  = ["Taro Yamada", "山田 太郎"]
logins = ["tyamada"]
hosts  = ["Taros-MacBook-Pro"]

It also adds this machine's login, home directory, hostname and git identity. Each value is expanded into the forms it shows up in: tyamada, t.yamada, Yamada Taro, -Users-tyamada-, Taro's MacBook Pro.

Session links from Claude Code and Codex are flagged without any config.

Beyond the working tree

kwangmyong github <owner> reads issues, PRs, comments, reviews, releases and gists through the API. git filter-repo doesn't reach those.

kwangmyong plan . writes the filter-repo inputs and a checklist to a temp directory outside the repository:

$ kwangmyong plan .
4 commit(s) from fee9bcc2ac41 would be rewritten, 0 tag(s) move

Hooks

kwangmyong hook pre-commit
kwangmyong hook pre-push
kwangmyong hook claude      # Claude Code PreToolUse

The Claude Code hook exits 2, so the agent gets the reason back instead of the command running. Here it is on the tool call for a gh pr create with a session link in the body:

$ kwangmyong hook claude < tool-call.json
kwangmyong: this command would publish your identity (1 finding(s)):
  generic.agent-session-url  command gh:3  ht…[509ace00]
Use ~/ or repo-relative paths, your public handle instead of a real name, the GitHub noreply address as the commit email, and drop agent session links.
$ echo $?
2

Not covered yet: wikis, Actions logs, Discussions.