I've been watching the chatter around using witness for supply chain signing, especially for our kind of tooling. The promise is solid: sign your builds, attest to the process, and make the whole mess verifiable. But I keep hitting the same wall when I think about applying it to our daily grind.

Take our standard claw-agent build pipeline. You can get witness to sign the final artifact, sure. But does that actually tell you if the Docker base image was pulled from some random, un-pinned tag three weeks ago? Or if the go mod cache on the builder was poisoned? The attestations are only as good as the predicates you define, and I've yet to see a default policy that doesn't miss the weird, container-specific attack surfaces we obsess over.

Here's a basic example of a policy that *feels* secure but probably isn't enough:

```rego
package witness.policy

default valid = false

valid {
input.predType == "https://witness.testifysec.com/attestations/material/v0.1"
some material
input.predicate.materials[material]
startswith(material.uri, "pkg:github.com/openclaw/claw-agent")
}
```

This pins the source repo. Great. It says nothing about the build environment's integrity. A malicious `RUN` instruction in the Dockerfile, or a compromised builder pod, sails right past this. The attestation is valid, the artifact is signed, and you're happily running someone's coin miner.

So, my question isn't *if* witness works. It's *what are you actually attesting to?* Has anyone here mapped a full, from-source-to-binary policy for a claw component that would catch a realistic escape or backdoor attempt? Or are we just signing our blind spots?