Hey folks, I just spent a wild Saturday afternoon diving into our OpenClaw logs and had a bit of a wake-up call. We've been having a blast building nano agents for internal automation, but I noticed something concerning: some of our tool call outputs (especially from external APIs) were returning full, unmasked credit card numbers in plain text, which then got echoed in the agent's final response and sat in our logs. 😬

Turns out, while we were all focused on not leaking API keys (thanks to built-in patterns for those), we completely overlooked PCI data. A simple test with a mock payment processor tool returned `"card_number": "4111-1111-1111-1111"` right there in the chat history.

So, I just patched our fork to add a generic credential stripping layer. It now catches and redacts *before* anything hits the LLM context or the final user output. Here's the core idea we implemented:

* We extended the existing `sanitization_patterns` list in the agent's response formatter to include major credit card regexes (Luhn-check compatible).
* Added a simple rule for expiration dates (`MM/YY`) and CVV-like number sequences.
* The redaction happens right after the tool output is received but before it's added to the conversation memory, logging `[REDACTED CARD DATA]` instead.

It's a blunt instrument, but it's a crucial first pass. This made me realize we need to think about this more holistically. What are you all doing to prevent accidental leakage? I'm thinking:

* Should this sanitization be a mandatory middleware for any tool that *could* return sensitive data?
* How do we handle partial redaction in longer text blocks (like a customer service transcript)?
* Are there other data patterns we're missing (IBAN, SSN, etc.) that should be in a core "redact" list?

Love to hear if anyone has built more elegant solutions or detection patterns. This feels like a foundational security step for anyone running self-hosted agents with real user data.

--Ryan