Context Engineering Template is a repository of instructions, examples, workflows, and validation practices that give AI coding assistants the information they need to complete software tasks. It is for developers working with Claude Code or other coding assistants, and the catalogue entries package parts of its workflow as commands, agents, instructions, and a skill.
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.
npx agentmods add commands/coleam00/context-engineering-intro/prime-frontendgit clone --depth 1 https://github.com/coleam00/context-engineering-introWrote 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.
[](https://agentmods.dev/commands/coleam00/context-engineering-intro/prime-frontend)<a href="https://agentmods.dev/commands/coleam00/context-engineering-intro/prime-frontend"><img src="https://agentmods.dev/badge/commands/coleam00/context-engineering-intro/prime-frontend.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00012 | $0.00654 |
| Opus 5 | $0.00006 | $0.00327 |
| Sonnet 5 | $0.00002 | $0.00131 |
| Haiku 4.5 | $0.00001 | $0.00065 |
Grade A, and why
prime-frontend 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 5d 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.
This is a copy
100% identical to prime-frontend — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prime Frontend: Web UI Orientation
Objective
Orient on the React frontend (packages/web/) before working on Web UI code. Also covers the
server-side Web adapter that feeds data to the UI via SSE.
Process
1. Understand the Frontend Stack
Read packages/web/package.json for exact dependency versions (React 19, Vite 6, TanStack
Query v5, React Router v7, Tailwind v4, shadcn/ui).
2. Understand the Route and Layout Structure
Read packages/web/src/App.tsx for routes, layout, QueryClient config, and ErrorBoundary.
List route pages:
!ls packages/web/src/routes/
List component directories:
!ls packages/web/src/components/
3. Understand Component Organization
List each component subdirectory to understand the breakdown (chat, conversations, dashboard,
layout, sidebar, ui, workflows):
!ls packages/web/src/components/chat/ packages/web/src/components/workflows/ packages/web/src/components/layout/
4. Understand Data Fetching
Read packages/web/src/lib/api.ts — API client with REST functions and SSE base URL logic.
Read hooks in packages/web/src/hooks/:
!ls packages/web/src/hooks/
Read packages/web/src/hooks/useSSE.ts for the SSE streaming pattern.
5. Understand Theme and Styling
Read packages/web/src/index.css for the Tailwind v4 @theme inline {} block — this is the
single source of truth for colors, fonts, and design tokens (dark theme only, blue accents,
Inter + JetBrains Mono fonts). Note: uses @import "tailwindcss" (not @tailwind directives).
6. Understand the Server-Side Web Adapter
Read packages/server/src/adapters/web/ files — the Web adapter uses SSE for streaming and
sendStructuredEvent() for rich tool call data.
!ls packages/server/src/adapters/web/
Read packages/server/src/routes/api.ts first 80 lines for API route structure.
7. Check Recent Frontend Activity
!git log -8 --oneline -- packages/web/ packages/server/src/adapters/web/
Output
Summarize (under 200 words):
Route Structure
- List each route page and its URL path
- Note active route and layout components
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.
- 5d ago First seen · 85 lines · 12 tokens per session scan A 7561dff46bb8
prime-frontend is a command published in the GitHub repository coleam00/context-engineering-intro (13,820 stars, last pushed 5mo ago), licensed MIT. It adds 12 tokens to every session and 654 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to prime-frontend, differing in 0 lines, and is treated as a copy.
Other commands, from other repositories
frontend
Injects context of all relevant cli files.
component
Scaffold a new React component grounded in the paper-mono primitives. Requires explicit kind or a nearest-existing-component match. No empty divs, no speculative scaffolding.
replan-remaining-work
Command "replan-remaining-work" from udecode/plate, covering command: re-plan remaining work, when to run, hard rule, invocation and refresh afterward.
speckit-gaia-plan-close
Close a plan after implementation+merge. Offers wiki-promote for the plan's consolidated SUMMARY.md, cold-consolidates an out-of-band merge, then early-reaps the local plan folder once cost is represented in cost.jsonl.
review-arch
Review the current branch for code quality, TypeScript, and React/Next.js patterns. Supports whole-branch review or scoped review by path, feature, or base branch.
speckit.clarify
This project uses the GAIA preset. Bare /speckit-clarify is not the clarify path here: core clarify writes an off-shape artifact (a ## Clarifications / ### Session block with five-word answers) and carries a question cap GAIA does not use. Run /gaia-spec instead — it drives GAIA's coverage-based Socratic clarify loop…