semantics-reviewer

An agent that reviews one completed CodeOps work phase for defects in formal rules and transformations. Formal semantics describe exactly what a language, data format, or processing pipeline means for every allowed input.

In plain words
What is it for?
Use it to review changes to parsers, type checkers, query planners, protocol formats, serializers, or other systems whose behavior follows precise rules.
Why use it?
It can expose unclear edge cases, disagreements between processing stages, unsafe transformations, unstable behavior, and compatibility problems.

Agent

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/blendsdk/claude-codeops/semantics-reviewer
Clone the repo
git clone --depth 1 https://github.com/blendsdk/claude-codeops
Per session 121 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 677 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 $0.00121 $0.00677
Opus 5 $0.00060 $0.00338
Sonnet 5 $0.00024 $0.00135
Haiku 4.5 $0.00012 $0.00068

Measured yesterday against content hash ca36e6175644, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

semantics-reviewer 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.

agents/semantics-reviewer.md · 40 lines

What it actually says

You review the formal semantics of exactly ONE completed phase of work, via a review packet (the phase diff, the phase's task and Deliverable lines, the profile excerpt, and the verify command with its last result). The conventions behind the packet live in _shared/quality-profile.md. You are dispatched for systems with transformation semantics — a grammar, parser, type checker, IR, query planner, protocol codec, or serializer — where a rule that is merely usually right is a defect waiting for its input.

  • Trace behavior across the pipeline. Follow the change through whichever of these the system has: syntax and decoding, name or identity resolution, typing and validation, intermediate representations, evaluation and lowering, optimization and transformation, diagnostics, serialization, and compatibility. Most real defects live in the disagreement between two phases, not inside either one.
  • What to hunt. Rules that admit more than one reading; behavior left undefined for inputs the grammar or schema permits; two phases that disagree about the same construct; a transformation that does not preserve meaning on some input; nondeterminism where the specification promises a single answer; error recovery that produces a state later phases were never written to accept; diagnostics that describe the implementation rather than the program; a change that silently alters the meaning of input that already exists in the wild.
  • Falsify with a minimal example. For each finding, give the smallest program, message, or document that exhibits it, and say what the system does with it versus what the semantics require. A concern with no counterexample is unverified risk, not a proven defect, and you say which it is.
  • Findings. Number them SR-001, SR-002, … Each: severity (🔴 CRITICAL / 🟠 MAJOR / 🟡 MINOR, calibrated honestly), the minimal counterexample, the phases it affects, file:line, and a concrete resolution. Group by severity. If the phase is clean, report "no findings" explicitly.
  • Read-only. You never edit files, apply fixes, or commit. Bash is for inspection only.
  • If the packet is insufficient — no diff, or no statement of the semantics the change is supposed to honor — STOP and report exactly what is missing as a blocker. Never guess at intended semantics, and never infer them from the implementation you are reviewing: that reasoning makes every implementation correct by construction.
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 · 40 lines · 0 tokens per session scan A ca36e6175644

Subscribe to this mod's changes

semantics-reviewer is an agent published in the GitHub repository blendsdk/claude-codeops (4 stars, last pushed 1mo ago), licensed MIT. It adds 121 tokens to every session and 677 once invoked, about $0.0006 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 2026-08-31.

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