context-engineering-kit

Advanced context engineering techniques and patterns for Claude Code, OpenCode, Cursor, Antigravity and more.

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Context Engineering Kit

A hand-crafted collection of advanced context engineering techniques and patterns with minimal token footprint, focused on improving agent result quality and predictability.

The marketplace is based on prompts our company's developers have used daily for a long time, supplemented by plugins from benchmarked papers and high-quality projects.

Key Features

• Simple to Use - Easy to install and use without any dependencies. Contains automatically used skills and self-explanatory commands.
• Token-Efficient - Carefully crafted prompts and architecture, preferring command-oriented skills with sub-agents over general information skills when possible, to minimize populating context with unnecessary information.
• Quality-Focused - Each plugin is focused on meaningfully improving agent results in a specific area.
• Granular - Install only the plugins you need. Each plugin loads only its specific agents, commands, and skills, without overlap or redundant skills.
• Scientifically proven - Plugins are based on proven techniques and patterns validated by reputable benchmarks and studies.
• Open-Standards - Skills are based on agentskills.io specification. The SDD plugin is based on the Arc42 specification standard for software development documentation.

News

Updates from key releases:

• v3.1.0: Improved Spec-Driven Development plugin generated code quality by embedding DDD/SOLID rules in the developer agent and adding a dedicated code-reviewer agent that applies functional and OOP best-practices rules together with Muda waste analysis to reduce code complexity and duplication.
• v3.0.0: Added support for AMP and Hermes agents. Tech Stack plugin now automatically injects typescript best practices when agent reads or writes TypeScript files.
• v2.2.0: Subagent-Driven Development plugin now works as a distilled version of SDD plugin using meta-judge and judge sub-agents for specification generation on the fly and in parallel to implementation. DDD plugin now includes Clean Architecture, DDD, SOLID, Functional Programming, and other pattern examples as rules that are automatically added to the context during code writing.
• v2.1.0: Spec-Driven Development plugin agents include high-level code quality guidelines from DDD plugin.
• v2.0.0: Spec-Driven Development plugin was rewritten from scratch. It is now able to produce working code in 99% of cases on real-life production projects!

Quick Start

Step 1: Install Marketplace and Plugins

Open Claude Code and add the Context Engineering Kit marketplace:

/plugin marketplace add NeoLabHQ/context-engineering-kit

This makes all plugins available for installation, but does not load any agents or skills into your context.

Install any plugin — for example, reflexion:

/plugin install reflexion@NeoLabHQ/context-engineering-kit

Each installed plugin loads only its specific agents, commands, and skills into Claude's context.

Install the extension directly from the repository:

gemini extensions install https://github.com/NeoLabHQ/context-engineering-kit

Note: This installs every plugin's skills and agents as a single bundle — there's no per-plugin selection like Claude Code's. Unfortunately, Gemini CLI does not support per-plugin selection. But you can delete skills and agents that you don't need, after installation.

Install the plugin directly from the repository's antigravity/ folder — Gemini CLI is not required:

agy plugin install https://github.com/NeoLabHQ/context-engineering-kit/antigravity

Note: This installs every plugin's skills and agents as a single bundle — there's no per-plugin selection like Claude Code's. Unfortunately, Antigravity CLI does not support per-plugin selection. But you can delete skills and agents that you don't need, after installation.

Run the vercel-labs/skills command in your terminal:

npx skills add NeoLabHQ/context-engineering-kit

You can pick which skills to install.

Note: Each provider uses its own agent format and npx skills does not support subagents, so this installation method won't provide the full experience.

You can use OpenSkills to install skills by running the following commands:

npx openskills install NeoLabHQ/context-engineering-kit
npx openskills sync

Step 2: Use Plugin

> claude "implement user authentication"
# Claude implements user authentication, then you can ask it to reflect on implementation

> /reflect
# It analyses results and suggests improvements
# If issues are obvious, it will fix them immediately
# If they are minor, it will suggest improvements that you can respond to
> fix the issues

# If you would like to prevent issues found during reflection from appearing again,
# ask Claude to extract resolution strategies and save the insights to project memory
> /memorize

Alternatively, you can use the reflect word in the initial prompt:

> claude "implement user authentication, then reflect"
# Claude implements user authentication,
# then hook automatically runs /reflect

In order to use this hook, you need to have bun installed. However, it is not required for the overall command.

Documentation

You can find the complete Context Engineering Kit documentation here.

However, the main plugins we recommend starting with are Subagent-Driven Development and Spec-Driven Development.

Agent Reliability Engineering

The three plugins in this marketplace are designed to improve how accurately and consistently the agent follows provided instructions and to reduce hallucinations and bias toward incorrect solutions. They are not competitors but rather complementary to each other, because they allow you to balance reliability vs. token cost. Here is a high-level comparison of different agent usage approaches and the probability of receiving results that are fully accurate and include zero hallucinations, based on task complexity:

Reliability metrics are based on more than year of real development usage on production projects.

Plugins List

To view all available plugins:

/plugin

• Reflexion - Feedback and refinement loops to improve output quality.
• Spec-Driven Development - Commands for specification-driven development, based on Continuous Learning + LLM-as-Judge + Agent Swarm. Achieves development as compilation through reliable code generation.
• Review - Open-source and higher quality version of CodeRabbit. Includes code and PR review commands and skills using multiple specialized agents with impact/confidence filtering. Free Github Actions integration available
• Git - Commands for commit and PR creation.
• Test-Driven Development - Commands for test-driven development and common anti-patterns, plus skills for testing using subagents.