# How to redact secrets and personal data from agent logs

> AI agent session files capture API keys, tokens, emails and customer data. How to find them in Claude Code and Codex logs, and how to mask them before sharing.

Source: https://groundedby.com/guides/redact-secrets-from-agent-logs (updated 2026-10-29)

Agents read your `.env` files, print command output and paste API responses into their context. All of it lands in the session file. Before you share a session with anyone - a colleague, a bug report, a buyer - assume it contains secrets.

## What ends up in session files

- **Keys and tokens** read from `.env` files, config files or command output.
- **Connection strings** with passwords inside them.
- **Emails, names and phone numbers** from databases, logs and customer records.
- **Internal hostnames, IPs and paths** that reveal how your systems are built.
- **Your own home directory**, which usually contains your username.

## Find them

Search your session files for common secret formats. A starting set:

```bash
cd ~/.claude/projects
# Provider keys with known prefixes
grep -rEl 'sk-(ant|proj|live)-[A-Za-z0-9_-]{20,}|ghp_[A-Za-z0-9]{36}|xox[bp]-[A-Za-z0-9-]{20,}|AKIA[0-9A-Z]{16}' . | head
# Private keys and connection strings
grep -rEl 'BEGIN (RSA |EC |OPENSSH )?PRIVATE KEY|postgres(ql)?://[^ ]+:[^ ]+@' . | head
# Email addresses
grep -rEoh '[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}' . | sort | uniq -c | sort -rn | head
```

Dedicated scanners do this better. **gitleaks** and **trufflehog** both scan plain directories, not only git repositories:

```bash
gitleaks dir ~/.claude/projects --report-path leaks.json
trufflehog filesystem ~/.claude/projects
```

## Mask them

For a session you will share:

1. **Copy it.** Never edit the original in place; agents may still read it.
2. **Replace each secret** with a typed placeholder, so the session still makes sense: `sk-ant-...` becomes `[ANTHROPIC_KEY]`, an email becomes `[EMAIL_1]`, a customer name becomes `[CUSTOMER_1]`.
3. **Keep placeholders consistent** across the session, so `[EMAIL_1]` is the same person every time.
4. **Replace your home path** (`/Users/yourname/`) with `~/`.
5. **Read the result.** Automated tools miss names, addresses and anything business-sensitive in plain prose.

## Rotate what leaked

If a live key sat in a session that was synced, shared or uploaded anywhere, rotate it at the provider. Masking the file does not un-share it.

## Prevent it

- Keep secrets out of the agent's reach: deny reads of `.env` files in your agent's permission settings where it supports them.
- Use a secrets manager and short-lived tokens, so a leaked value expires.
- Review before sharing, every time.

groundedby's marketplace will run this redaction on your machine and show you the masked session before anything is offered. [Privacy model](/docs/privacy-model).

## Questions

**Is deleting a key from the log enough if it leaked?**

No. If a live key appears in a session you shared or synced anywhere, rotate it. Redaction protects what you share next; rotation fixes what already leaked.

**Can I just search for the word "key"?**

It helps, but keys rarely sit next to the word key. Search for the known formats of the services you use, for long random strings, and for email addresses.