Claude Code Swarms: How to Run Parallel AI Agents
Claude Code's Tasks feature just went viral. Developers are running 5, 10, even 20 parallel AI agents working simultaneously on different parts of their codebase. They're calling it "Swarms" - and it's changing how fast you can ship.
"Claude Code tasks might go down as the most impactful feature they have built. The Swarm is here." - @seejayhess
Here's how it works, when to use it, and the patterns that actually work.
What are Swarms?
The Task tool in Claude Code lets you spawn sub-agents that work independently. Each agent gets its own context, runs in parallel, and returns results when done.
The "Swarm" pattern uses this to:
- Plan - A lead agent breaks work into independent pieces
- Delegate - Spawn specialist agents for each piece
- Run in parallel - All agents work simultaneously
- Synthesize - Lead agent combines results
One developer reports building apps "by orders of magnitude" faster. Another discovered a hidden "Swarms" mode by patching the CLI that auto-delegates to specialist agents.
When to use parallel agents
Swarms work best when tasks are independent. If task B needs the output of task A, run them sequentially. If they don't depend on each other, parallelize.
Good for parallel:
- Writing tests for different modules
- Researching multiple topics
- Reviewing several files
- Building independent components
- Exploring different approaches
Keep sequential:
- Database schema before queries
- Types before implementation
- Plan approval before building
- Any task where output feeds the next
How to trigger parallel execution
Claude Code runs Tasks in parallel when you make multiple Task tool calls in a single message. The key is giving Claude clear instructions:
"These are independent tasks. Run them in parallel:
1. Agent 1: Write unit tests for UserService
2. Agent 2: Write unit tests for OrderService
3. Agent 3: Write unit tests for PaymentService
Launch all three simultaneously."
The explicit "run in parallel" instruction matters. Without it, Claude might serialize unnecessarily.
Effective swarm prompts
Each agent starts with fresh context. They don't share your conversation history. Give them everything they need:
"Agent task: Review the authentication module.
Context:
- Project uses TypeScript + Express
- Auth is in src/auth/
- We use JWT tokens stored in httpOnly cookies
- Main concern: are there security vulnerabilities?
Deliverable:
- List of potential issues
- Severity rating for each
- Suggested fixes
Do not modify any code."
Notice the structure: clear task, full context, expected deliverable, constraints.
The Lead-Clone vs Lead-Specialist debate
Some developers prefer "Master-Clone" architecture - identical agents that each handle a slice of work. Others use "Lead-Specialist" - dedicated experts for different domains.
All agents get the same prompt template, just different inputs:
# Clone agent template
"Review file: {filename}
Apply our standard code review checklist.
Return: issues, suggestions, rating."
Different agents have different expertise:
# Security specialist
"You are a security expert. Review for vulnerabilities."
# Performance specialist
"You are a performance expert. Identify bottlenecks."
# UX specialist
"You are a UX expert. Evaluate user experience."
Master-Clone is simpler and avoids context gatekeeping. Lead-Specialist can go deeper on specific concerns. Try both.
Pitfalls to avoid
Too many agents. More isn't always better. 3-5 parallel agents is usually the sweet spot. Beyond that, coordination overhead increases and quality drops.
Missing context. Agents don't know what you told the main conversation. Include everything they need in the task prompt itself.
Dependent tasks. If you parallelize tasks that actually depend on each other, you'll get inconsistent or broken results. Analyze dependencies first.
No synthesis. Parallel agents produce parallel outputs. Someone needs to combine, resolve conflicts, and make decisions. That's usually you or a dedicated synthesis agent.
Real workflow: Feature implementation
Here's a concrete example of using swarms for a new feature:
# Phase 1: Research (parallel)
Agent 1: "Research how similar features are implemented in our codebase"
Agent 2: "Check for existing utilities we can reuse"
Agent 3: "Review the API spec and identify edge cases"
# Phase 2: Plan (sequential)
Main: "Based on research, create implementation plan"
User: "Approve plan"
# Phase 3: Implement (parallel)
Agent 1: "Implement database schema and migrations"
Agent 2: "Implement API endpoint handlers"
Agent 3: "Implement frontend components"
# Phase 4: Verify (sequential)
Main: "Run tests, verify integration, fix issues"
The key insight: OODA then parallel. Observe, Orient, Decide yourself. Then Act with parallel agents.
Token considerations
Running multiple agents means multiple context windows. Costs add up. Some tips:
- Use the Explore agent type for quick codebase searches
- Keep individual tasks focused - don't give agents open-ended prompts
- Use haiku model for straightforward tasks
- Set max_turns limits to prevent runaway agents
The swarm is here
This pattern is spreading fast. Developers who master parallel agents will ship faster than those who don't. The learning curve is understanding:
- Which tasks are truly independent
- How to give agents complete context
- When to parallelize vs. serialize
- How to synthesize results
Start with 2-3 agents on clearly independent tasks. Build intuition. Then scale up.
63+ prompts for Claude Code
Including multi-agent patterns and parallel execution templates.
Get All 63+ PromptsKey takeaways
- Tasks feature enables parallel AI agents ("swarms")
- Only parallelize independent tasks
- Give each agent complete context - they don't share
- 3-5 agents is the sweet spot
- OODA yourself, then delegate execution
- Always synthesize parallel outputs
The future of coding isn't one AI helping you. It's a swarm of specialists working in parallel while you orchestrate.