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, and that is the trap you are walking into. So don't hand back the writeup. Find the one or two facts the whole thing depends on and prove them by running code. Words are where you start, not what you ship.
### 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.
…
The line at the top of this page pins the label git:20260827.04830a9, 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.
GET https://markdownregistry.com/api/v1/artifacts/art_zbbbbv4zuvm5rnkz
GET https://markdownregistry.com/api/v1/resolve?ref=painhardcore/pstack/blast-radius
GET https://markdownregistry.com/api/v1/blob/00464891e7f004cb40cb5d4b0d3b76d8a296e8df21c675a962a8deef738a7b11
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.
painhardcore/pstack · .opencode/skills/architect/SKILL.md · Sketch types, signatures, and module structure before code, then stay in the loop while implementation fills in. Use…
painhardcore/pstack · .opencode/skills/arena/SKILL.md · Spawn N parallel candidates at the same task, pick a base, graft the strongest parts of the losers into it. Use for…
painhardcore/pstack · .opencode/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
painhardcore/pstack · .opencode/skills/create-verification-skill/SKILL.md · Generate a project-local verification skill that drives your app the way a user does — any language, framework, or…
painhardcore/pstack · .opencode/skills/figure-it-out/SKILL.md · Design an auditable playbook when no narrower one fits: a large migration, an ambitious multi-part change, or work a…
painhardcore/pstack · .opencode/skills/how/SKILL.md · Explain how a subsystem works, trace a runtime flow, or determine where code and ownership belong before making a…
painhardcore/pstack · .opencode/skills/interrogate/SKILL.md · Use for "interrogate", "adversarial review", "multi-model review", "challenge this", "stress test this code", "find…
painhardcore/pstack · .opencode/skills/principle-boundary-discipline/SKILL.md · Apply when wiring validation, error handling, or framework adapters. Concentrate guards at system boundaries (CLI…
cursor/plugins · pstack/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
cursor/plugins · harness/pstack/claude-code/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
michael-denyer/pstack-claude · plugins/pstack/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
backnotprop/pstack · skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
pedrohcgs/claude-code-my-workflow · .claude/skills/blast-radius/SKILL.md · Before and after changing anything shared — a function's return value, a signature, a schema, a label set, a config…
pixeltable/pixeltable · .claude/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
athola/claude-night-market · plugins/pensive/skills/blast-radius/SKILL.md · Analyzes code change impact with risk scoring and affected-node mapping. Use before merging to understand what a change…
parcha-ai/parcha-skills · blast-radius/skills/blast-radius/SKILL.md · Find what a change could break somewhere else before it ships, beyond the diff, and prove the one fact it's safe…
