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name: create-subagent description: >- Create custom subagents for specialized AI tasks. Use when you want to create a new type of subagent, set up task-specific agents, configure code reviewers, debuggers, or domain-specific assistants with custom prompts. disable-model-invocation: true

Creating Custom Subagents

This skill guides you through creating custom subagents for Cursor. Subagents are specialized AI assistants that run in isolated contexts with custom system prompts.

When to Use Subagents

Subagents help you:

  • Preserve context by isolating exploration from your main conversation
  • Specialize behavior with focused system prompts for specific domains
  • Reuse configurations across projects with user-level subagents

Inferring from Context

If you have previous conversation context, infer the subagent's purpose and behavior from what was discussed. Create the subagent based on specialized tasks or workflows that emerged in the conversation.

Subagent Locations

LocationScopePriority
.cursor/agents/Current projectHigher
~/.cursor/agents/All your projectsLower

When multiple subagents share the same name, the higher-priority location wins.

Project subagents (.cursor/agents/): Ideal for codebase-specific agents. Check into version control to share with your team.

User subagents (~/.cursor/agents/): Personal agents available across all your projects.

Subagent File Format

Create a .md file with YAML frontmatter and a markdown body (the system prompt):

---
name: code-reviewer
description: Reviews code for quality and best practices
---

You are a code reviewer. When invoked, analyze the code and provide
specific, actionable feedback on quality, security, and best practices.

Required Fields

FieldDescription
nameUnique identifier (lowercase letters and hyphens only)
descriptionWhen to delegate to this subagent (be specific!)

Writing Effective Descriptions

The description is critical - the AI uses it to decide when to delegate.

# ❌ Too vague
description: Helps with code

# ✅ Specific and actionable
description: Expert code review specialist. Proactively reviews code for quality, security, and maintainability. Use immediately after writing or modifying code.

Include "use proactively" to encourage automatic delegation.

Example Subagents

Code Reviewer

---
name: code-reviewer
description: Expert code review specialist. Proactively reviews code for quality, security, and maintainability. Use immediately after writing or modifying code.
---

You are a senior code reviewer ensuring high standards of code quality and security.

When invoked:
1. Run git diff to see recent changes
2. Focus on modified files
3. Begin review immediately

Review checklist:
- Code is clear and readable
- Functions and variables are well-named
- No duplicated code
- Proper error handling
- No exposed secrets or API keys
- Input validation implemented
- Good test coverage
- Performance considerations addressed

Provide feedback organized by priority:
- Critical issues (must fix)
- Warnings (should fix)
- Suggestions (consider improving)

Include specific examples of how to fix issues.

Debugger

---
name: debugger
description: Debugging specialist for errors, test failures, and unexpected behavior. Use proactively when encountering any issues.
---

You are an expert debugger specializing in root cause analysis.

When invoked:
1. Capture error message and stack trace
2. Identify reproduction steps
3. Isolate the failure location
4. Implement minimal fix
5. Verify solution works

Debugging process:
- Analyze error messages and logs
- Check recent code changes
- Form and test hypotheses
- Add strategic debug logging
- Inspect variable states

For each issue, provide:
- Root cause explanation
- Evidence supporting the diagnosis
- Specific code fix
- Testing approach
- Prevention recommendations

Focus on fixing the underlying issue, not the symptoms.

Data Scientist

---
name: data-scientist
description: Data analysis expert for SQL queries, BigQuery operations, and data insights. Use proactively for data analysis tasks and queries.
---

You are a data scientist specializing in SQL and BigQuery analysis.

When invoked:
1. Understand the data analysis requirement
2. Write efficient SQL queries
3. Use BigQuery command line tools (bq) when appropriate
4. Analyze and summarize results
5. Present findings clearly

Key practices:
- Write optimized SQL queries with proper filters
- Use appropriate aggregations and joins
- Include comments explaining complex logic
- Format results for readability
- Provide data-driven recommendations

For each analysis:
- Explain the query approach
- Document any assumptions
- Highlight key findings
- Suggest next steps based on data

Always ensure queries are efficient and cost-effective.

Subagent Creation Workflow

Step 1: Decide the Scope

  • Project-level (.cursor/agents/): For codebase-specific agents shared with team
  • User-level (~/.cursor/agents/): For personal agents across all projects

Step 2: Create the File

# For project-level
mkdir -p .cursor/agents
touch .cursor/agents/my-agent.md

# For user-level
mkdir -p ~/.cursor/agents
touch ~/.cursor/agents/my-agent.md

Step 3: Define Configuration

Write the frontmatter with the required fields (name and description).

Step 4: Write the System Prompt

The body becomes the system prompt. Be specific about:

  • What the agent should do when invoked
  • The workflow or process to follow
  • Output format and structure
  • Any constraints or guidelines

Step 5: Test the Agent

Ask the AI to use your new agent:

Use the my-agent subagent to [task description]

Best Practices

  1. Design focused subagents: Each should excel at one specific task
  2. Write detailed descriptions: Include trigger terms so the AI knows when to delegate
  3. Check into version control: Share project subagents with your team
  4. Use proactive language: Include "use proactively" in descriptions

Troubleshooting

Subagent Not Found

  • Ensure file is in .cursor/agents/ or ~/.cursor/agents/
  • Check file has .md extension
  • Verify YAML frontmatter syntax is valid

Overview

create-subagent is a free skill on OpenRuna. Create custom subagents for specialized AI tasks. Use when you want to create a new type of subagent, set up task-specific agents, configure code reviewers, debuggers, or domain-sp

What this skill does

Reach for "create-subagent" whenever you need a reliable skill for real work across ChatGPT, Claude, Gemini, and Cursor. Create custom subagents for specialized AI tasks. Use when you want to create a new type of subagent, set up task-specific agents, configure code reviewers, debuggers, or domain-specific assistants with custom prompts. On OpenRuna it sits inside a connected graph of related skills, tools, and datasets, so branching into adjacent resources is one click away. Open a new conversation and paste it in, wire it into an agent, or keep it in your team's prompt library.

Use cases

  • Combine it with related tools and prompts in the same OpenRuna category to build an end-to-end workflow.
  • Reach for it during planning or review sessions when you want consistent, AI-assisted structure.
  • Use "create-subagent" when you need a repeatable skill for professional work without rewriting instructions every time.
  • Hand "create-subagent" to a new teammate so their skill output matches your team's quality bar from day one.

Example output

Running this skill produces output shaped like the source material below:

# Creating Custom Subagents

This skill guides you through creating custom subagents for Cursor. Subagents are specialized AI assistants that run in isolated contexts with custom system prompts.

## When to Use Subagents

Subagents help you:
- **Preserve context** by isolating exploration from your main conversation
- **Specialize behavior** with focused system prompts for specific domains
- **Reuse configurations** across projects with user-level subagents

### Inferring from Context

If you have previous conversation context, infer the subagent's purpose and behavior from what was discussed.…

Results vary by model and temperature; treat the first response as a draft and refine it with follow-up prompts.

Tips by platform

Claude

Claude works best when you paste this skill up front and ask it to outline its plan before writing. Use the artifact panel to refine structured output turn by turn.

ChatGPT

In ChatGPT, start a fresh chat and paste this skill verbatim, then follow up with "apply this to [your context]." Pick a current GPT model for coding or reasoning tasks.

Cursor

In Cursor, lift the key instructions from this skill into .cursorrules or a SKILL.md file, then reference it in Agent mode with @ mentions. Keep the title in a comment so teammates can find it on OpenRuna.

Frequently asked questions

What is "create-subagent"?
It is a skill listed on OpenRuna — Create custom subagents for specialized AI tasks. Use when you want to create a new type of subagent, set up task-specific agents, configure code reviewers, debuggers, or domain-specific assistants with custom prompts. You can copy and adapt it for ChatGPT, Claude, Cursor, or any other AI assistant.
Is "create-subagent" free to use?
Most OpenRuna resources are open or CC0-licensed. Check the license shown on this page before commercial use; premium collections are clearly marked as such.
How do I get the best results from this skill?
Replace any placeholders, add your project context, and ask the model to confirm its assumptions first. Iterate over 2–3 follow-up turns rather than expecting a perfect first response.
Does "create-subagent" work with both Claude and ChatGPT?
Yes — it is model-agnostic text, so it runs on Claude, ChatGPT, Gemini, and Cursor. The tips on this page cover each of those assistants specifically.
Where can I find resources related to "create-subagent"?
Scroll to the Related resources section on this page, or open the matching category hub on OpenRuna to find connected prompts, tools, agents, and datasets in the same topic area.

Related resources