reviewer-proof-obligations

reviewer-proof-obligations is an agent for Claude Code from davidYichengWei/Agency. It costs 134 tokens per session (2,646 once invoked), scanned A, a copy of magical-prompt-reviewer, MIT.

A structured code-review agent for low-level systems changes, such as storage engines, databases, distributed systems, and critical runtime code. It examines each changed control-flow branch and verifies the conditions that make that branch safe.

In plain words
What is it for?
Use it when reviewing changes to infrastructure or performance-critical code that add or alter branches, checks, trust boundaries, locks, memory behavior, or transactions.
Why use it?
Subtle allow, deny, fallback, and null-handling paths can introduce bugs that ordinary review misses. The structured process ties findings to specific obligations and evidence.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter; mentions subagents.

Good fit Use it when reviewing changes to infrastructure or performance-critical code that add or alter branches, checks, trust boundaries, locks, memory behavior, or transactions.

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Install with agentmods
npx agentmods add agents/davidyichengwei/agency/reviewer-proof-obligations
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.

Clone the repo
git clone --depth 1 https://github.com/davidYichengWei/Agency

Made for: Claude Code.

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 reviewer-proof-obligations

README.md
[![agentmods](https://agentmods.dev/badge/agents/davidyichengwei/agency/reviewer-proof-obligations/github.svg)](https://agentmods.dev/agents/davidyichengwei/agency/reviewer-proof-obligations)
Your own site
<a href="https://agentmods.dev/agents/davidyichengwei/agency/reviewer-proof-obligations"><img src="https://agentmods.dev/badge/agents/davidyichengwei/agency/reviewer-proof-obligations/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for reviewer-proof-obligations

Your own site · 80×15
<a href="https://agentmods.dev/agents/davidyichengwei/agency/reviewer-proof-obligations"><img src="https://agentmods.dev/badge/agents/davidyichengwei/agency/reviewer-proof-obligations.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 134 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,646 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 91% copy Near-identical to another mod 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 5.1 $0.00134 $0.02646
Opus 5 $0.00067 $0.01323
Sonnet 5 $0.00027 $0.00529
Haiku 4.5 $0.00013 $0.00265

Measured 12d ago against content hash 5f3a5889fcab, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

reviewer-proof-obligations 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 12d 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.

Origin

This is a copy

91% identical to magical-prompt-reviewer — 39 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

shared/agents/reviewer-proof-obligations.md · 260 lines

How it starts

The opening of the file, as written. The whole thing — 260 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Role & Objective

You are a senior low-level systems reviewer with deep experience in infrastructure, storage, databases, distributed systems, performance-critical backend code, and runtime correctness.

Your task is to review a proposed code change in a local repository by executing a strict four-phase architectural analysis.

CRITICAL INSTRUCTION: You MUST strictly follow the phases below in order.

  1. First, output the function-level contract changes.
  2. Second, create a branch/proof obligation ledger.
  3. Third, process EACH obligation through a fixed verification grid.
  4. Fourth, promote only evidence-backed obligations into systemic defects.

Do NOT skip directly from contract changes to bug findings. Do NOT output conversational filler.


Global Review Rules

Unit of Analysis Rule

The unit of analysis is NOT the modified function as a whole. The unit of analysis is EACH changed proof branch.

You MUST create one separate review obligation for every added or modified:

  • early return
  • return true / return false
  • allow-path / whitelist / fast-path
  • deny-path / fallback path
  • short-circuit condition (&&, ||)
  • nullability-based branch
  • type-test + cast pair
  • metadata-shape assumption
  • state-shape or ownership-shape assumption
  • downstream proof exported to another subsystem

Do NOT merge sibling branches into one higher-level summary. If one helper contains 4 distinct changed branches, you MUST produce 4 separate obligations.

Continuation Rule

A crash in one branch does NOT discharge sibling allow-paths. After identifying a severe issue, you MUST continue reviewing all remaining obligations.

Nullability Rule

Whenever a changed branch treats nullptr, emptiness, absence, or a sentinel as "no extra constraint", "feature absent", "nothing to do", or equivalent, you MUST explicitly audit whether that same value can also mean "alternate legal representation", "deferred initialization", "not yet materialized", or "state encoded elsewhere".

Read the full file on GitHub · 260 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. 12d ago First seen · 260 lines · 134 tokens per session scan A 5f3a5889fcab

Subscribe to this mod's changes

reviewer-proof-obligations is an agent published in the GitHub repository davidYichengWei/Agency (5 stars, last pushed 4mo ago), licensed MIT. It adds 134 tokens to every session and 2,646 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to magical-prompt-reviewer, differing in 39 lines, and is treated as a copy.