pr-impact

A command for estimating which parts of a codebase may be affected by a pull request or branch. It follows the call graph, which maps which code components depend on or call other components.

In plain words
What is it for?
Use it with a pull-request number or branch name to analyze impact, limit traversal depth, identify highly connected code, and optionally check for conflicts. It can first build a codebase index if one is missing.
Why use it?
It helps reveal downstream code that may break or need testing before a change is merged.

Command

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 commands/helweg/open-codebase-index/pr-impact
Clone the repo
git clone --depth 1 https://github.com/Helweg/open-codebase-index
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 199 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00009 $0.00199
Opus 5 $0.00005 $0.00100
Sonnet 5 $0.00002 $0.00040
Haiku 4.5 $0.00001 $0.00020

Measured 2d ago against content hash 8ee32d6f8f3b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

pr-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 2d ago.

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.

commands/pr-impact.md · 24 lines

What it actually says

Analyze the impact of a pull request or branch before merging.

User input: $ARGUMENTS

Interpret input as follows:

  • pr=N or plain number at the start → set pr
  • branch=<name> or plain branch name → set branch
  • maxDepth=N → set max traversal depth
  • hubThreshold=N → set hub node threshold
  • checkConflicts or conflicts → set checkConflicts=true

Call pr_impact with the parsed arguments.

Examples:

  • /pr-impact 42 → pr=42
  • /pr-impact branch=feature/auth → branch="feature/auth"
  • /pr-impact branch=feature/x maxDepth=3 checkConflicts → branch="feature/x", maxDepth=3, checkConflicts=true

If the index doesn't exist, run index_codebase first.

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. 2d ago First seen · 24 lines · 9 tokens per session scan A 8ee32d6f8f3b

Subscribe to this mod's changes

pr-impact is a command published in the GitHub repository Helweg/open-codebase-index (185 stars, last pushed 3d ago), licensed MIT. It adds 9 tokens to every session and 199 once invoked, about $0.0000 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 2026-08-30.