annotate-screenshots

A screenshot annotation tool that adds boxes, arrows, labels, freehand marks, or redactions to images or captured web pages.

In plain words
What is it for?
Use it to point out interface changes or bugs, explain a visual difference, or redact sensitive information from PNG and JPEG screenshots.
Why use it?
It makes the exact area needing attention clear to reviewers and can hide secrets before a screenshot is shared.

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/buildinternet/uploads/annotate-screenshots
Any agent
npx skills add buildinternet/uploads --skill annotate-screenshots
Clone the repo
git clone --depth 1 https://github.com/buildinternet/uploads

Made for: Claude Code, Codex.

Per session 169 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,800 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 $0.00169 $0.01800
Opus 5 $0.00084 $0.00900
Sonnet 5 $0.00034 $0.00360
Haiku 4.5 $0.00017 $0.00180

Measured yesterday against content hash e72a922bb910, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

annotate-screenshots 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.

skills/annotate-screenshots/SKILL.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Annotating screenshots

When to annotate

Add annotations when a screenshot needs to draw the reader's eye somewhere specific — a new element, a bug, a diff — rather than leaving them to find it in the caption. A plain before/after pair is often enough; reach for annotation when "look at the top-right corner" is easier to say with an arrow than with words, or when a screenshot contains a secret that must be hidden before it's shared anywhere (uploads.sh URLs are public).

Two commands, same underlying spec format:

Command Input Targeting
uploads screenshot <url|file.html> --annotate <spec> captures a live page CSS selectors (preferred) or pixel coordinates
uploads annotate <image> --spec <spec> an existing PNG/JPEG file pixel coordinates only — selectors are rejected

Prefer selectors, resolved live, over guessing pixel coordinates. An agent estimating x/y/w/h by eye is unreliable — it's easy to point at the wrong element or clip a box awkwardly. uploads screenshot --annotate resolves a CSS selector against the real DOM at capture time (local backend only in v1 — --via remote rejects selector-bearing specs up front), so use it whenever you're capturing the page yourself. Fall back to pixel coordinates with uploads annotate only when you're marking up an image you already have and there's no live page to query — a screenshot someone else took, a photo, a diagram exported from elsewhere.

The spec format

A spec is a JSON document: { "version": 1, "annotations": [...] }. annotations is a non-empty array; each entry has a type plus fields for that type. House style (color, stroke weight, sketchy roughness, font) is fixed and not configurable — the one style knob is a per-annotation color override.

Read the full file on GitHub · 161 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. yesterday First seen · 161 lines · 169 tokens per session scan A e72a922bb910

Subscribe to this mod's changes

annotate-screenshots is a skill published in the GitHub repository buildinternet/uploads (19 stars, last pushed yesterday), licensed Apache-2.0. It adds 169 tokens to every session and 1,800 once invoked, about $0.0008 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.