plannotator

A local browser-based review tool for plans, code changes, documents, URLs, folders, and local applications. Reviewers can annotate the material and return structured feedback.

In plain words
What is it for?
Reviewing plans and diffs, inspecting GitHub pull requests or GitLab merge requests, and annotating project files or running apps.
Why use it?
It gives people a shared place to mark problems, suggest changes, approve work, or close a review during an agent workflow.

Skill for Claude CodeCodex

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 skills/backnotprop/plannotator/plannotator
Any agent
npx skills add backnotprop/plannotator --skill plannotator
Clone the repo
git clone --depth 1 https://github.com/backnotprop/plannotator

Made for: Claude Code, Codex.

Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,289 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 $0.00073 $0.03289
Opus 5 $0.00036 $0.01644
Sonnet 5 $0.00015 $0.00658
Haiku 4.5 $0.00007 $0.00329

Measured yesterday against content hash 13731ec9b7ae, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plannotator 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.

apps/skills/core/plannotator/SKILL.md · 186 lines

How it starts

The opening of the file, as written. The whole thing — 186 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plannotator CLI Reference

Plannotator is a local, browser-based review layer for agent workflows: it opens plans, diffs, and documents in an annotation UI, the human marks them up, and the structured feedback comes back to you on stdout. It installs as a single plannotator binary plus per-host hooks, so plan review fires automatically when you exit plan mode; every other surface is launched explicitly from the CLI. A session runs on a random localhost port (fixed port 19432 in remote mode) and blocks until the reviewer submits feedback, approves, or closes the tab.

This skill is the knowledge layer. The plannotator-review, plannotator-annotate, and plannotator-last skills are thin launchers for the three most common actions; use this reference when you need to pick the right command or flags yourself.

Choose the command

The user wants Run
Review a plan you produced Nothing. Plan review opens automatically on plan exit via hooks. Never run bare plannotator yourself.
Review current code changes plannotator review
Review a GitHub PR or GitLab MR plannotator review <PR_URL>
Annotate a markdown, text, config, or HTML file plannotator annotate <file>
Annotate a web page plannotator annotate <https-url>
Annotate a running local app (dev server) plannotator annotate <http://localhost:PORT/>
Pick a file to annotate from a folder plannotator annotate <folder/>
Annotate your latest assistant message plannotator last
Browse past plan decisions plannotator archive
Export or share a Guided Review plannotator guide export / plannotator guide share
Reopen or list live sessions plannotator sessions

Session model

Every review or annotate command starts a local web server, opens the browser, and blocks until the human decides. That can take minutes. Launch it with a long (or no) command timeout, or in the background, then read stdout when the process exits. Do not kill the process to "finish" a review; a session that ends without a decision reads as no feedback.

Read the full file on GitHub · 186 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 186 lines · 73 tokens per session scan A 13731ec9b7ae

Subscribe to this mod's changes

plannotator is a skill published in the GitHub repository backnotprop/plannotator (8,256 stars, last pushed 2d ago), licensed Apache-2.0. It adds 73 tokens to every session and 3,289 once invoked, about $0.0004 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.

Related

Other skills, from other repositories