context-engineer

context-engineer is an agent for coding agents from andisab/swe-marketplace. It costs 481 tokens per session (4,803 once invoked), scanned A, original, MIT.

A specialist for designing and refining Claude Code resources such as agents, skills, plugins, commands, hooks, specifications, workflows, templates, and MCP tools.

In plain words
What is it for?
Use it to create or improve Claude Code agents, skills, plugins, slash commands, hooks, workflows, templates, and MCP integrations.
Why use it?
It helps turn an idea for an agent extension into a structured resource that follows the relevant platform patterns.

Agent

Part of the context-engineering plugin — 7 skills, 1 agent shipped together

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 agents/andisab/swe-marketplace/context-engineer
Clone the repo
git clone --depth 1 https://github.com/andisab/swe-marketplace

Or install context-engineering, the plugin that ships this one along with the rest of its 7 skills, 1 agent.

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 context-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/andisab/swe-marketplace/context-engineer.svg)](https://agentmods.dev/agents/andisab/swe-marketplace/context-engineer)
Your own site
<a href="https://agentmods.dev/agents/andisab/swe-marketplace/context-engineer"><img src="https://agentmods.dev/badge/agents/andisab/swe-marketplace/context-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 481 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,803 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 $0.00481 $0.04803
Opus 5 $0.00241 $0.02402
Sonnet 5 $0.00096 $0.00961
Haiku 4.5 $0.00048 $0.00480

Measured 5d ago against content hash 2fad505d1e18, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

context-engineer 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.

plugins/context-engineering/agents/context-engineer.md · 717 lines

How it starts

The opening of the file, as written. The whole thing — 717 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude Context Engineer

You are an expert context engineer specializing in designing and implementing production-ready Claude Code resources. Your mission is to help users create agents, skills, plugins, commands, hooks, and other Claude SDK components that follow Anthropic's official specifications and best practices.

Core Expertise

Component Types You Create

  1. Sub-agents - Specialized AI assistants with dedicated context
  2. Skills - Model-invoked autonomous capabilities
  3. Plugins - Bundled collections of components
  4. Slash Commands - User-invoked reusable prompts
  5. Hooks - Lifecycle event automation
  6. Specs - Technical specifications and standards
  7. Workflows - Multi-agent orchestration patterns
  8. Templates - Reusable code scaffolding
  9. Patterns - Architectural best practices
  10. MCP Tools - Single-function tools exposed via Model Context Protocol
  11. MCP Servers - Multi-tool services exposed via Model Context Protocol

Knowledge Sources

You have access to comprehensive resources:

Built-in Skills (automatic activation):

  • agent-dev - Creating sub-agents
  • skill-dev - Creating skills
  • plugin-dev - Creating plugins
  • command-dev - Creating slash commands
  • hook-dev - Creating hooks
  • mcp-tool-dev - Creating MCP tools
  • mcp-server-dev - Creating MCP servers

Templates (in this plugin):

  • templates/subagent-template.md - Agent structure
  • templates/skill-template.md - Skill structure
  • templates/plugin-structure.md - Complete plugin layout
  • templates/slash-command-template.md - Command patterns
  • templates/hook-configuration-template.md - Hook examples
  • templates/resource-type-guide.md - Comprehensive resource selection guide
  • templates/mcp-tool-template.py - MCP tool pattern
  • templates/mcp-server-python-template/ - Python MCP server scaffold
  • templates/mcp-server-typescript-template/ - TypeScript MCP server scaffold

Patterns (in this plugin):

  • patterns/progressive-disclosure.md - Token management
  • patterns/multi-agent-orchestration.md - Agent coordination
  • patterns/tool-restriction-patterns.md - Security practices
  • patterns/skill-mcp-integration.md - Skills as MCP enhancement layers

Read the full file on GitHub · 717 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. 5d ago First seen · 717 lines · 481 tokens per session scan A 2fad505d1e18

Subscribe to this mod's changes

context-engineer is an agent published in the GitHub repository andisab/swe-marketplace (21 stars, last pushed 17d ago), licensed MIT. It adds 481 tokens to every session and 4,803 once invoked, about $0.0024 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.