Reflexion
Collection of commands that force LLM to reflect on previous response and output. Based on papers like Self-Refine and Reflexion. These techniques improve the output of large language models by introducing feedback and refinement loops.
- Type
- Plugin
- Repository
- NeoLabHQ/context-engineering-kit
- GitHub stars
- 1.7k
- License
- GPL-3.0
- Repo last updated
- Aug 26, 2026
- Source file
- plugins/reflexion/.claude-plugin/plugin.json
- Version
- 3.0.0
- Author
- Vlad Goncharov
What Reflexion is
Reflexion is a plugin published in the NeoLabHQ/context-engineering-kit repository on GitHub, which has about 1.7k stars. The repository describes itself as: “Hand-crafted Claude Code Skills focused on improving agent results quality. Compatible with OpenCode, Cursor, Antigravity, Gemini CLI, and others. Includes CodeRabbit open-source alternative.”
A plugin is a package that bundles skills, slash commands, subagents, hooks, and MCP connectors so they install together. Plugins are plain files with a manifest at .claude-plugin/plugin.json, and they work in both Claude Code and Claude Cowork.
Installing Reflexion adds everything it ships in one step. Connectors inside a plugin still need to be connected separately, and hooks and subagents only run in Cowork and Claude Code, not in regular chat.
How to install Reflexion
Claude Code
- Add the repository as a plugin marketplace: claude plugin marketplace add NeoLabHQ/context-engineering-kit
- Install the plugin: claude plugin install reflexion@<marketplace-name>, using the marketplace name from the repository's .claude-plugin/marketplace.json.
- Restart the session if the new skills or commands don't appear straight away.
Claude Cowork
- Open Customize → Plugins and choose Add marketplace.
- Enter NeoLabHQ/context-engineering-kit (the owner/repo shorthand works for GitHub).
- Find Reflexion in the list, click Install, then connect any connectors it needs from its Connectors tab.
New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.
Inside the source file
An excerpt from plugins/reflexion/.claude-plugin/plugin.json, shared under the repository's GPL-3.0 license. Read the full file on GitHub.
Self-refinement framework that introduces feedback and refinement loops to improve output quality through iterative improvement, complexity triage, and verification.
Focused on:
- Self-refinement - Agents review and improve their own outputs
- Multi-agent review - Specialized agents critique from different perspectives
- Iterative improvement - Systematic loops that converge on higher quality
- Memory integration - Lessons learned persist across interactions
Plugin Target
- Decrease hallucinations - reflection usually allows you to get rid of hallucinations by verifying the output
- Make output quality more predictable - same model usually produces more similar output after reflection, rather than after one shot prompt
- Improve output quality - reflection usually allows you to improve the output by identifying areas that were missed or misunderstood in one shot prompt
Overview
The Reflexion plugin implements multiple scientifically-proven techniques for improving LLM outputs through self-reflection, critique, and memory updates. It enables Claude to evaluate its own work, identify weaknesses, and generate improved versions.
Plugin is based on papers like Self-Refine and Reflexion. These techniques improve the output of large language models by introducing feedback and refinement loops.
They are proven to increase output quality by 8–21% based on both automatic metrics and human preferences across seven diverse tasks, including dialogue generation, coding, and mathematical reasoning, when compared to standard one-step model outputs.
On top of that, the plugin is based on the Agentic Context Engineering paper that uses memory updates after reflection, and consistently outperforms strong baselines by 10.6% on agents.
Quick Start
# Install the plugin
/plugin install reflexion@NeoLabHQ/context-engineering-kit> claude "implement user authentication"
# Claude implements user authentication, then you can ask it to reflect on implementation
> /reflexion: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 it to avoid issues that were found during reflection to appear again,
# ask claude to extract resolution strategies and save the insights to project memory
> /reflexion:memorizeAlternatively, you can use the reflect word in initial prompt:
> claude "implement user authentication, then reflect"
# Claude implements user authentication,
# then hook automatically runs /reflexion:reflectIn order to use this hook, need to have bun installed. But for overall command it is not required.
Usage Examples
Automatic Reflection with Hooks
The plugin includes optional hooks that automatically trigger reflection when you include the word "reflect" in your prompt. This removes the need to manually run /reflexion:reflect after each task.
How It Works
- Include the word "reflect" anywhere in your prompt
- Claude completes your task
- The hook automatically triggers /reflexion:reflect
- Claude reviews and improves its work
# Automatic reflection triggered by "reflect" keyword
> Fix the bug in auth.ts then reflect
# Claude fixes the bug, then automatically reflects on the work
> Implement the feature, reflect on your work
# Same behavior - "reflect" triggers automatic reflectionImportant: Only the exact word "reflect" triggers automatic reflection. Words like "reflection", "reflective", or "reflects" do not trigger it.
Commands
- /reflect - Self-Refinement. Reflect on previous response and output, based on Self-refinement framework for iterative improvement with complexity triage and verification
- /critique - Multi-Perspective Critique. Comprehensive multi-perspective review using specialized judges with debate and consensus building
- /memorize - Memory Updates. Curates insights from reflections and critiques into CLAUDE.md using Agentic Context Engineering
Before you install
- Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
- Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
- Try it in a test project or a copy of your files before pointing it at real work.
- Pin the version you tested, and review changes before updating.
- Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.
FAQ
What is Reflexion?
Reflexion is a plugin for Claude Code and Claude Cowork from the NeoLabHQ/context-engineering-kit repository on GitHub. Collection of commands that force LLM to reflect on previous response and output. Based on papers like Self-Refine and Reflexion. These techniques improve the output of large language models by introducing feedback and refinement loops.
How do I install Reflexion in Claude Code?
Add the repository as a plugin marketplace: claude plugin marketplace add NeoLabHQ/context-engineering-kit Install the plugin: claude plugin install reflexion@<marketplace-name>, using the marketplace name from the repository's .claude-plugin/marketplace.json. Restart the session if the new skills or commands don't appear straight away.
Can I use Reflexion in Claude Cowork?
Open Customize → Plugins and choose Add marketplace. Enter NeoLabHQ/context-engineering-kit (the owner/repo shorthand works for GitHub). Find Reflexion in the list, click Install, then connect any connectors it needs from its Connectors tab.
Is Reflexion safe to install?
It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.
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