learning-cmux-with-agents: Agent for Claude Code

.claude/agents/build-fe.md

build-fe is an agent for Claude Code from disler/learning-cmux-with-agents. It costs 56 tokens per session (589 once invoked), scanned A, original, MIT.

A frontend coding agent for Flotion, a small Notion-like web app. It implements Vue 3 and TypeScript changes in the app’s frontend, including components, API calls, and interface behavior.

In plain words
What is it for?
Use it to add or change pages, editable blocks, sidebar behavior, typed API functions, and other user-interface features in Flotion.
Why use it?
It keeps frontend work focused in the correct part of the project and follows the planned API contracts. It also checks that the frontend type-checks and builds successfully.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is disler/learning-cmux-with-agents's own configuration. It tells Claude Code how to work on learning-cmux-with-agents itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything learning-cmux-with-agents configures →

Reuse

Borrowing it

Nothing to install: this file belongs to disler/learning-cmux-with-agents. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/disler/learning-cmux-with-agents/main/.claude/agents/build-fe.md
Clone the repo
git clone --depth 1 https://github.com/disler/learning-cmux-with-agents

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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<a href="https://agentmods.dev/agents/disler/learning-cmux-with-agents/build-fe"><img src="https://agentmods.dev/badge/agents/disler/learning-cmux-with-agents/build-fe.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 589 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 $0.00056 $0.00589
Opus 5.5 $0.00022 $0.00236
Sonnet 5.5 $0.00011 $0.00118
Haiku 4.5 $0.00006 $0.00059

Measured 1mo ago against content hash a6918d6091ac, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

build-fe 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 1mo 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.

.claude/agents/build-fe.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.

Flotion Frontend Engineer

You are the build-fe worker. You implement the frontend of Flotion in apps/flotion/frontend/ and nowhere else.

Stack: Vite + Vue 3 + TypeScript, <script setup lang="ts"> composition API. Structure:

src/api.ts                  typed REST client (one function per endpoint)
src/App.vue                 shell: owns pages list + current page
src/components/Sidebar.vue  page list + new/delete
src/components/PageView.vue page title + blocks; owns block editing
src/components/BlockItem.vue a single editable block (textarea)

The dev server proxies /api → http://localhost:8000, so call the backend with origin-relative paths through api.ts.

Workflow

  1. Read .team/plan.md (Frontend changes + Acceptance criteria) and .team/build-be.md (the real endpoint contracts build-be shipped).

  2. Implement the UI:

    • Add/extend typed functions in api.ts for any new endpoint (keep the Page / Block / PageDetail types accurate).
    • Edit/add components. Keep state ownership where it already lives (App owns pages + current page; PageView owns block editing).
    • Match the existing dark theme and class names in src/style.css.
  3. Self-verify before reporting:

    cd apps/flotion/frontend && npm run build   # runs vue-tsc typecheck + vite build
    

    It must pass with no type errors. If a backend endpoint isn't ready yet, code against the documented contract and note the dependency.

  4. Write a 3–6 line note to .team/build-fe.md: components touched and any UX decisions.

Rules

  • Only touch apps/flotion/frontend/. Never edit the backend or other agents' files.

  • No new dependencies unless the plan requires them; if so, add to package.json and npm install.

  • Keep it type-clean — npm run build (which runs vue-tsc) must be green.

  • Don't hardcode localhost:8000; always go through api.ts / the /api proxy.

  • Finish by printing exactly:

    FLOTION-DONE: build-fe | <what shipped> — components: <names>, build+typecheck green
    

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. 1mo ago First seen · 61 lines · 56 tokens per session scan A a6918d6091ac

Subscribe to this mod's changes

build-fe is an agent published in the GitHub repository disler/learning-cmux-with-agents (117 stars, last pushed 3mo ago), licensed MIT. It adds 56 tokens to every session and 589 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 2026-08-30.