assess-impact

assess-impact is a cursor rule for Cursor from danielvm-git/bigpowers. It costs 63 tokens per session (792 once invoked), scanned A, original, MIT.

Analyze the blast radius of a proposed change before any code is written. Maps dependents, affected stories, and test coverage. Produces specs/IMPACTLATEST.md. Use before plan-work on any non-trivial change, when touching a shared module, or when the user asks "what does this break?".

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/danielvm-git/bigpowers/assess-impact
Clone the repo
git clone --depth 1 https://github.com/danielvm-git/bigpowers

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for assess-impact

README.md
[![agentmods](https://agentmods.dev/badge/rules/danielvm-git/bigpowers/assess-impact.svg)](https://agentmods.dev/rules/danielvm-git/bigpowers/assess-impact)
Your own site
<a href="https://agentmods.dev/rules/danielvm-git/bigpowers/assess-impact"><img src="https://agentmods.dev/badge/rules/danielvm-git/bigpowers/assess-impact.svg" alt="Measured on agentmods" height="20"></a>
Per session 63 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 792 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00063 $0.00792
Opus 5 $0.00032 $0.00396
Sonnet 5 $0.00013 $0.00158
Haiku 4.5 $0.00006 $0.00079

Measured today against content hash 9f4e9e51dab7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

assess-impact scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/assess-impact.mdc · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Assess Impact

HARD GATE — Run this skill before plan-work whenever a change touches an existing module, symbol, or file used by more than one caller. Skip only for net-new code with no existing dependents.

Find the blast radius of the proposed change before a single line is written.

Modes

  • Default: full impact analysis (dependents + affected stories + test coverage mapping)
  • --lightweight: Fast fan-in/fan-out only (<10s). Maps callers and imports without test coverage mapping. Used by build-epic step 2 as a pre-plan gate. Risk score > 7 triggers a mandatory grill-me session before proceeding.

Process

1. Identify the target

Name the symbol, module, or file being changed. If the user hasn't specified, ask one question: "What exactly are you changing?"

2. Find dependents

grep -rn "[symbol-name]" . --include="*.ts" | grep -v node_modules
git log --oneline -10 -- [file-path]

→ verify: test -f specs/IMPACT_LATEST.md || test -d specs/bugs

3. Map to release plan stories

Read specs/release-plan.yaml + epic capsule directories (if it exists). For each dependent found in Step 2, identify which story owns that module. List stories that will be affected by the change.

→ verify: test -f specs/release-plan.yaml && grep -ci "stor" specs/release-plan.yaml

4. List test coverage

Find tests that exercise the target:

grep -rn "[symbol-name]" . --include="*.test.*" --include="*.spec.*"

→ verify: test -d specs/epics || test -d skills

5. Classify risk

Level Condition
Low ≤ 2 callers, all covered by tests
Medium 3–10 callers, partial test coverage
High > 10 callers, or shared API/interface, or no tests

6. Write specs/IMPACT_LATEST.md

## Target
[symbol or file being changed]

## Dependents ([count])
- [file]: [caller or usage]

## Affected Stories
- Story [X.Y]: [title]

## Test Coverage
- [test file]: covers [scenario]
- Gap: [untested behavior]

## Risk: Low / Medium / High
[One-sentence rationale]

## Recommended action
[Proceed / Add tests first / Discuss design]

Read the full file on GitHub · 91 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today First seen · 91 lines · 63 tokens per session scan A 9f4e9e51dab7

Subscribe to this mod's changes

assess-impact is a cursor rule published in the GitHub repository danielvm-git/bigpowers (163 stars, last pushed 2d ago), licensed MIT. It adds 63 tokens to every session and 792 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.