Find what a change breaks somewhere else before it ships, beyond the diff and past where grep stops, and prove the one fact it is safe because of by running real code. Use when asked for the blast radius of a change, when deciding whether an in-flight change is safe to merge, or when reviewing a small diff you do not trust yet.
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. Listing the callers is not the job: any agent can grep those in a second. The job is the breakage grep will not show you.
This is the implementing session's own discipline, run before or during the change, pre-merge. [adversarial-review](../adversarial-review/SKILL.md) is the other side of the line: it reviews a finished change with isolated finders and a skeptic gate. Blast radius is what you run on your own work while it is still yours.
## The writeup is not the deliverable
A blast-radius writeup that sounds right is worth nothing on its own. It reads as convincing whether or not it is true, and that is the trap. The deliverable is the proof: find the one fact the change's safety depends on (occasionally a change rests on two; then each gets the same treatment) and get it proven by running code. Words are where you start, not what you hand back.
## The evidence ladder
For each fact the change's safety depends on, push it as far down this ladder as is cheap, and say where it stopped.
1. **You said so.** Worthless on its own.
…
The line at the top of this page pins the label git:20260819.3277965, 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 (5872 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
timharris707/skills · 44 stars · license MIT · pushed 2026-10-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_62im5cfbz6ueotcp
GET https://markdownregistry.com/api/v1/resolve?ref=timharris707/skills/blast-radius
GET https://markdownregistry.com/api/v1/blob/0c14345b3e629c44e9fb853700f94345501cf765a744c857aead3510c74335ae
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.
timharris707/skills · editions/codex/overrides/skills/investigate/ingest/SKILL.md · For a media file or URL shared with a goal, transcription requests, or takeaways from a call, demo, playtest, or video…
timharris707/skills · plugins/clickai-codex/skills/author/huh/SKILL.md · When a message did not land or pasted agent output needs translation, restate it plainly, expand shorthand, separate…
timharris707/skills · plugins/clickai-codex/skills/author/plainspoken/SKILL.md · For chat replies, status updates, review comments, and commit messages, write plainly without AI tells. Also use to…
timharris707/skills · plugins/clickai-codex/skills/author/writing-for-agents/SKILL.md · For skills, standing agent instructions, recorded rules, or documents agents skip, write and prune reliable triggers…
timharris707/skills · plugins/clickai-codex/skills/author/writing-for-humans/SKILL.md · For public-facing drafts, pages that read like agent documentation, or a final AI-tell scrub, write clear human copy in…
timharris707/skills · plugins/clickai-codex/skills/decide/advisory-board/SKILL.md · For an explicitly requested advisory board, roundtable, panel, idea tournament, multi-model review or debate, red-team…
timharris707/skills · plugins/clickai-codex/skills/decide/decision-map/SKILL.md · When asked to chart a decision map, work a map ticket, or plan work whose open decisions gate each other, map the…
timharris707/skills · plugins/clickai-codex/skills/decide/grilling/SKILL.md · When asked to grill, stress-test, or pressure-test an idea, or before a decision map or spec rests on an untested…
timharris707/skills · plugins/clickai-codex/skills/investigate/codebase-review/SKILL.md · Before an upcoming feature, when merged work crosses the recorded review threshold, or when implementation exposes…
timharris707/skills · plugins/clickai-codex/skills/investigate/ingest/SKILL.md · For a media file or URL shared with a goal, transcription requests, or takeaways from a call, demo, playtest, or video…
timharris707/skills · plugins/clickai-codex/skills/investigate/prototype/SKILL.md · When discussion or static mockups cannot settle how something should look, behave, or feel, build a disposable…
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…
