Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe because of by running real code instead of writing it up. Use for 'blast radius of X', 'what could this break', or reviewing a small diff you don't trust.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Blast radius
Find what a change breaks somewhere else, before it ships. Use for "blast radius of X", "what could this break", or reviewing a small diff you don't trust yet.
Companion to `how` and `why`. `how` tells you what the code does. `why` tells you why it's shaped that way. Blast radius tells you what it breaks somewhere else.
Listing the callers is not the job. The agent can grep those in a second. The job is the breakage grep won't show you.
## Don't trust your own writeup
A blast-radius writeup that sounds right is worthless. It reads as convincing whether or not it's true. So don't hand back the writeup. Find the one or two facts the whole thing depends on and prove them by running code.
### How sure are you
For each fact the change's safety depends on, get it as far down this list as is cheap, and say where it stopped.
1. You said so. Worthless on its own.
2. You pointed at the line. A real `file:line`, or the library's own source.
3. You showed the bad case can't happen. You walked the failure step by step and it doesn't reach.
4. You ran it. A script or test that calls the real code and fails loud if you're wrong.
5. You reproduced it in the running app.
…
The line at the top of this page pins the label git:20261006.f7c5841, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (3851 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag
Source
GitHub
iap/pstack-hermes · 30 stars · license a license file GitHub does not identify · pushed 2026-10-31 · branch dist
API
GET https://markdownregistry.com/api/v1/artifacts/art_qxzltjmw3una4vo7
GET https://markdownregistry.com/api/v1/resolve?ref=iap/pstack-hermes/blast-radius
GET https://markdownregistry.com/api/v1/blob/5f02db9101ccf26c20254718f0fcd5c2c7ac5d4292b0e0923d0944ac47237aff
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
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