web-apps

web-apps is a skill for Claude Code, Codex from langchain-ai/open-swe. It costs 43 tokens per session (811 once invoked), scanned A, original, MIT.

A guide for building self-contained HTML apps that run inside the Open SWE web interface. The apps run in a restricted frame and use approved host services for storage, GitHub, live rooms, or an agent.

In plain words
What is it for?
Use it to create, preview, and publish small sidebar apps or plugins, such as notes or repository tools.
Why use it?
It explains the required app manifest, permissions, and publishing process so an app can run in the web interface without direct network access.

Skill for Claude CodeCodex ✓ vendor

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create, preview, and publish small sidebar apps or plugins, such as notes or repository tools.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/langchain-ai/open-swe/web-apps
About the project

Open SWE is an open-source software factory that gives coding tasks to an asynchronous agent, which investigates repositories, changes code, validates the results, and delivers pull requests. Engineering teams use it to automate code changes, reviews, CI follow-up, and related repository work from dashboards and connected tools.

langchain-ai/open-swe · 11,175 stars · on GitHub · langchain.com

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.

Any agent
npx skills add langchain-ai/open-swe --skill web-apps
Clone the repo
git clone --depth 1 https://github.com/langchain-ai/open-swe

Made for: Claude Code, Codex.

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 web-apps

README.md
[![agentmods](https://agentmods.dev/badge/skills/langchain-ai/open-swe/web-apps/github.svg)](https://agentmods.dev/skills/langchain-ai/open-swe/web-apps)
Your own site
<a href="https://agentmods.dev/skills/langchain-ai/open-swe/web-apps"><img src="https://agentmods.dev/badge/skills/langchain-ai/open-swe/web-apps/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 web-apps

Your own site · 80×15
<a href="https://agentmods.dev/skills/langchain-ai/open-swe/web-apps"><img src="https://agentmods.dev/badge/skills/langchain-ai/open-swe/web-apps.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 811 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 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 5.1 $0.00043 $0.00811
Opus 5.5 $0.00017 $0.00324
Sonnet 5.5 $0.00009 $0.00162
Haiku 4.5 $0.00004 $0.00081

Measured today against content hash ce404ba2c55d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

web-apps 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 today.

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.

openswe/bundled_skills/web-apps/SKILL.md · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Open SWE apps

An app is one self-contained HTML file. The web UI runs it full screen from the person's sidebar, in a sandboxed frame with no network: it reaches storage, GitHub, live rooms and an agent only through the host API, as the person using it, within the permissions in its manifest.

The manifest

Embed it in the HTML as a JSON script:

<script type="application/openswe-plugin+json">
{
  "name": "standup-notes",
  "displayName": "Standup notes",
  "version": "0.1.0",
  "description": "Notes for the daily standup",
  "sidebar": { "label": "Standup", "icon": "notebook" },
  "permissions": ["storage"]
}
</script>
  • name: lowercase letters, digits and dashes. Publishing under the same name makes a new version of the same app.
  • sidebar.icon: one of puzzle-piece, notebook, file-text, book-open, kanban, chart-bar, chat-circle, calendar, lightbulb.
  • permissions: ask for the fewest. storage (JSON documents, private or per repository), realtime (live rooms with presence), github:read, github:write (branches, commits, pull requests), agent (a chat dock with tools the app provides).

Start from the starter

plugins/starter in langchain-ai/open-swe is an app ready to change: React, the Macaw design system (Open SWE's own components, which follow the web UI's light and dark theme), Tailwind, the plugin SDK, and a Vite build that writes the one self-contained file with manifest.json inside it. Macaw is published on npm; take the SDK and starter from the repository:

APPS=/workspace/.openswe-apps/open-swe
git clone --depth 1 --filter=blob:none --sparse https://github.com/langchain-ai/open-swe "$APPS"
git -C "$APPS" sparse-checkout set plugins/sdk plugins/starter
cp -r "$APPS/plugins/starter" "$APPS/plugins/<name>"
cd "$APPS/plugins/<name>" && npm install && npm run build

Clone it there, never over a checkout of the thread's own repository, and keep the app beside plugins/sdk, where its package.json finds the local SDK. Edit manifest.json and src/App.tsx; npm run build writes bundle/index.html, the file to preview. Build the UI from Macaw's components (@langchain/macaw-components/<Component>: Button, Card, Input, Select, Tabs, Dialog, Text and the rest) and its tokens (p-space-4, text-secondary, bg-surface-level-2) rather than your own styles, so the app looks like the web UI around it. The SDK's README.md and src/client.ts document the host API.

Read the full file on GitHub · 61 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. today First seen · 61 lines · 43 tokens per session scan A ce404ba2c55d

Subscribe to this mod's changes

web-apps is a skill published in the GitHub repository langchain-ai/open-swe (11,175 stars, last pushed yesterday), licensed MIT. It adds 43 tokens to every session and 811 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-11-06.

Related

web-apps compared with skills from other repositories

web-apps next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
web-appslangchain-ai/open-sweSkill11kyesterdayMITA43Claude Code, Codex
langbot-devlangbot-app/LangBotSkill19kyesterdayApache-2.0A136Claude Code, Codex
langbot-plugin-devlangbot-app/LangBotSkill19kyesterdayApache-2.0A115Claude Code, Codex
langbot-skills-maintenancelangbot-app/LangBotSkill19kyesterdayApache-2.0A49Claude Code, Codex
langbot-env-setuplangbot-app/LangBotSkill19kyesterdayApache-2.0A67Claude Code, Codex
langbot-deploylangbot-app/LangBotSkill19kyesterdayApache-2.0B104Claude Code, Codex
lynkrFast-Editor/LynkrSkill639yesterdayApache-2.0A50Claude Code, Codex