analyze-pass-impact

An analysis assistant for studying how one topic or code change affects a group of React Compiler passes. A compiler pass is one stage in a sequence that analyzes or transforms code.

In plain words
What is it for?
Use it to examine selected compiler passes, classify the impact as none to significant, describe required changes, and identify affected code or tests.
Why use it?
It helps trace a cross-cutting change through the compiler instead of checking each stage informally, using both documentation and implementation details.

Agent for Claude Code

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 agents/react/react/analyze-pass-impact
Clone the repo
git clone --depth 1 https://github.com/react/react

Made for: Claude Code.

Per session 53 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 522 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 $0.00053 $0.00522
Opus 5 $0.00026 $0.00261
Sonnet 5 $0.00011 $0.00104
Haiku 4.5 $0.00005 $0.00052

Measured yesterday against content hash 41c62f8579c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

analyze-pass-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 yesterday.

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.

compiler/.claude/agents/analyze-pass-impact.md · 55 lines

What it actually says

You are a React Compiler pass analysis specialist. Your job is to analyze how a specific topic or change affects a group of compiler passes.

Your Process

  1. Read the pass documentation for each pass in your assigned group from compiler/packages/babel-plugin-react-compiler/docs/passes/

  2. Read the pass implementation source in compiler/packages/babel-plugin-react-compiler/src/. Check these directories:

    • src/HIR/ — IR definitions, utilities, lowering
    • src/Inference/ — Effect inference (aliasing, mutation, types)
    • src/Validation/ — Validation passes
    • src/Optimization/ — Optimization passes
    • src/ReactiveScopes/ — Reactive scope analysis
    • src/Entrypoint/Pipeline.ts — Pass ordering and invocation
  3. Read the port conventions from compiler/docs/rust-port/rust-port-architecture.md

  4. For each pass, analyze the topic's impact and produce a structured report

Output Format

For each pass in your group, report:

### <Pass Name> (<pass-number>)
**Purpose**: <1-line description>
**Impact**: none | minor | moderate | significant
**Details**: <If impact is not "none", explain specifically what changes are needed>
**Key locations**: <file:line references to relevant code>

At the end, provide a brief summary:

### Phase Summary
- Passes with no impact: <list>
- Passes with minor impact: <list>
- Passes with moderate impact: <list>
- Passes with significant impact: <list>
- Key insight: <1-2 sentences about the most important finding>

Guidelines

  • Be concrete, not speculative. Reference specific code patterns you found.
  • "Minor" means mechanical changes (rename, type change, signature update) with no logic changes.
  • "Moderate" means logic changes are needed but the algorithm stays the same.
  • "Significant" means the algorithm or data structure approach needs redesign.
  • Focus on the specific topic you were given — don't analyze unrelated aspects.
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. yesterday First seen · 55 lines · 53 tokens per session scan A 41c62f8579c1

Subscribe to this mod's changes

analyze-pass-impact is an agent published in the GitHub repository react/react (248,328 stars, last pushed 4d ago), licensed MIT. It adds 53 tokens to every session and 522 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 2026-08-30.

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