How to find leaked API keys and secrets on your own machine

Most leaked keys are not stolen by genius. They sit in a file that many programs can read. Here is where to look, how to judge what you find, and what to do next.

  ~/project/
  ├── .env              ◀ normal if private + git-ignored
  ├── config.php        ◀ key pasted "just for now"      OPEN
  ├── .git/             ◀ the old key lives on in history   OPEN
  ├── backup.env.bak    ◀ a web server will serve this      OPEN
  └── ~/.aws/credentials ◀ every process of yours can read it

Where secrets hide

• Project code and config: a key pasted into config.php, settings.py or a test script "just for now".
• .env files: normal and fine when the file is private and git-ignored. A problem when it is committed, world-readable, or copied into a backup.
• Git history: deleting a key from the current file does not delete it from older commits.
• Cloud and tool credentials: ~/.aws/credentials, .npmrc with a token, Docker and Kubernetes configs.
• Agent and MCP config: tokens inside mcp.json or an agent's settings file.
• Web roots of servers: backups like .env.bak or config.php~ that a web server happily serves.

How to judge a finding

A key in a private, git-ignored .env in your own project is normal. The same key becomes a finding when one of these is true:

1. The file is world-readable (other accounts or services can open it).
2. The file is tracked or was ever committed to Git.
3. It sits in a folder a web server publishes.
4. It is a long-lived token with write power (publishing packages, cloud admin).

How Dante does it

The deep run (deep, or weekly if you agree to a schedule) searches your project folders for secrets using patterns for 1,111 formats - AWS, GitHub, Stripe, private keys, database URLs and many more. It first looks which systems are in the project (package.json, composer.json, requirements.txt) and only uses the fitting patterns, so it stays fast and quiet. On a hit it looks closer: file rights, is it in Git, was it ever committed, is it ignored.

It shows the file, the line and the kind of secret - never the value. Example files (*.example) and placeholder lines are skipped, as are node_modules, .git, vendor and build folders. Nothing leaves your machine.

user ❯ deep
  OPEN  GitHub token  app/deploy.sh  line 8
        in Git history (committed 2026-03-02) · file mode 644
  SAFE  AWS key  .env  (private, git-ignored: normal for a local .env)

What to do when you find one

1. Rotate first. Assume the key is known. Create a new one at the provider and revoke the old one. Removing the line is not enough.
2. Move the new secret to a place that is not committed: a private git-ignored .env, your OS keychain, or a secrets manager.
3. If it was committed, rotating matters more than rewriting history; rewrite only to stop further spreading.
4. Tighten file rights: private files should be readable by you only (mode 600 on Mac and Linux).

Questions people ask

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