Coordinate multiple AI agents working on the same codebase or project simultaneously. Covers git worktree isolation, file locking strategies, message passing between agents, shared state management, conflict resolution, task decomposition for parallel agents, and patterns from Claude Code, Cursor, Devin, and similar multi-agent developer tools. Activate on: "multi-agent", "parallel agents", "agent coordination", "worktree isolation", "concurrent agents", "file locking agents", "agent conflict resolution", "swarming agents", "agent message passing", "parallel development", "agent orchestration", "ccswarm", "port daddy". NOT for: single-agent behavior patterns (use agentic-patterns), agent infrastructure selection (use agentic-infrastructure-2026), DAG topology design (use next-move), or designing product invocation surfaces and hot/durable protocol contracts for swarms (use swarm-invocation-designer).
allowed-tools
Read,Write,Edit,Bash,Glob,Grep,WebSearch,WebFetch
metadata
{"category":"AI & Agents","tags":["multi-agent","coordination","git-worktree","parallel","isolation","conflict-resolution","swarming","orchestration"],"pairs-with":[{"skill":"agentic-infrastructure-2026","reason":"Infrastructure layer that multi-agent coordination runs on top of"},{"skill":"always-on-agent-architecture","reason":"Always-on agents need coordination when running in parallel"},{"skill":"agentic-patterns","reason":"Individual agent patterns compose into multi-agent coordination"}]}
category
Agent & Orchestration
tags
["multi","agent","coordination","git","ai","dag"]
Multi-Agent Coordination
You are an expert in coordinating multiple AI agents working simultaneously on shared codebases and projects. You understand git worktree isolation, file locking, message passing, shared state, and conflict resolution. The goal: multiple agents producing high-quality work in parallel without stepping on each other, with clean integration of their outputs.
When to Use
Use for:
Running multiple AI agents in parallel on the same repository
Designing git worktree isolation strategies for agent sandboxing
Building file locking and resource coordination systems
Implementing message passing between concurrent agents
Resolving merge conflicts from parallel agent work
Decomposing tasks for optimal parallel agent execution
Setting up Port Daddy or similar resource coordination
Do NOT use for:
Single-agent behavior and tool use (use agentic-patterns)
Building DAG topologies (use next-move or windags-architect)
Git basics or branching strategy (use git-best-practices)
The Coordination Problem
When multiple agents work on the same codebase simultaneously, three things go wrong:
File conflicts: Two agents edit the same file, producing incompatible changes
Resource contention: Agents compete for ports, API quotas, build tools, test databases
Semantic conflicts: Agents produce individually correct changes that are collectively broken (e.g., Agent A renames a function, Agent B calls the old name)
The industry-standard pattern for multi-agent development. Each agent gets its own worktree -- same repo history, independent working tree.
How It Works
main repo (.git)
|
+-- worktree-agent-1/ (branch: feat/auth-module)
| task: "implement OAuth login"
| files: independent working copy
|
+-- worktree-agent-2/ (branch: feat/api-tests)
| task: "write API integration tests"
| files: independent working copy
|
+-- worktree-agent-3/ (branch: feat/db-schema)
task: "design user table migration"
files: independent working copy
Worktree Lifecycle
#!/bin/bash# create-agent-worktree.sh
TASK_ID=$1
BRANCH_NAME="agent/${TASK_ID}"
WORKTREE_DIR="/tmp/agent-worktrees/${TASK_ID}"# Create branch and worktree from current main
git branch "${BRANCH_NAME}" main
git worktree add "${WORKTREE_DIR}""${BRANCH_NAME}"echo"Agent worktree ready at ${WORKTREE_DIR}"echo"Branch: ${BRANCH_NAME}"
Phase 1: PARALLEL WORK
Agent 1 ──work──> commit(s) on branch agent/task-1
Agent 2 ──work──> commit(s) on branch agent/task-2
Agent 3 ──work──> commit(s) on branch agent/task-3
Phase 2: SEQUENTIAL MERGE (order matters)
main ← merge agent/task-1 (no conflicts, clean)
main ← merge agent/task-2 (possible conflicts with task-1)
main ← merge agent/task-3 (possible conflicts with task-1+2)
Phase 3: VALIDATION
Run full test suite on merged main
If tests fail → identify which merge caused it → fix or revert
Merge Order Optimization
Merge in dependency order, not completion order:
Build dependency graph from agent task dependencies
Topological sort (dependencies merge first)
Within same dependency level, merge the agent with fewest file overlaps first (fewer conflicts)
Always run tests after each merge, not just at the end
File Locking and Resource Coordination
The Port Daddy Pattern
Port Daddy provides a coordination service for claiming shared resources (ports, files, locks) across agents:
# Agent registers itself
pd agent register --agent session-123 \
--identity "project:auth-module" \
--purpose "implementing OAuth login flow"# Start a session
pd session start --purpose "OAuth implementation" --agent session-123 --lifecycle durable
# Claim files (prevents other agents from editing them)
pd session files claim session-123 \
src/auth/oauth.ts \
src/auth/middleware.ts \
src/routes/login.ts
# Claim a port for dev server
PORT=$(pd claim auth-service -q)
# Add notes for other agents to see
pd note "OAuth provider config needs GOOGLE_CLIENT_ID env var" \
--type discovery
# Check for dead agent sessions and salvage their work
pd salvage --project myproject
# End session when done
pd session end session-123
File-Level Locking Strategy
When formal tooling like Port Daddy is unavailable, implement a FileCoordinator with a Map<string, FileLock> where each lock records: path, agentId, claimedAt, purpose. Key operations:
claim(agentId, paths[]): Check all paths for existing locks by other agents. If conflicts exist, return them with a suggested resolution. Otherwise, claim all paths atomically.
release(agentId): Release all locks held by the agent when its task completes or it crashes.
Conflict suggestion: If all conflicts are with one agent, suggest sequencing. If multiple agents, suggest splitting work to avoid the contested files.
Task Decomposition for Parallel Agents
The quality of parallel agent work depends entirely on how you decompose the task.
The Independence Principle
Maximize independence between agent tasks. The ideal decomposition has:
Zero file overlap: Each agent touches different files
Clear interfaces: Agents agree on function signatures / API contracts upfront
Unidirectional dependencies: Agent B reads Agent A's output, not vice versa
Before assigning tasks to parallel agents, build the coupling matrix:
Task A Task B Task C Task D
Task A - HIGH LOW NONE
Task B HIGH - LOW NONE
Task C LOW LOW - HIGH
Task D NONE NONE HIGH -
Optimal grouping:
Wave 1: [Task A + Task B] sequential, [Task C + Task D] sequential
But A/B and C/D can run in parallel because NONE coupling between groups
Coupling Level
File Overlap
Can Parallelize?
Strategy
NONE
0 files shared
Yes, freely
Assign to separate agents
LOW
Config/types only
Yes, with contract
Define shared types first
HIGH
Core files shared
No
Sequence or merge carefully
CRITICAL
Same function
Never
Single agent only
Message Passing Between Agents
Event Types
Agents communicate through four event types:
Event
Purpose
Example
discovery
Share findings that affect other agents
"User model uses soft-delete, not DELETE"
completion
Signal that work is done and branch is ready
"API types defined on branch agent/user-types"
conflict
Flag that two agents need the same resource
"Both need to modify src/auth/middleware.ts"
request
Ask another agent for something
"Need AuthMiddleware type exported before I can proceed"
The Shared Context Document
For simpler coordination, agents read/write a shared markdown document (e.g., .windags/coordination.md) with four sections: Active Agents (who, what task, status, files claimed), Discoveries (findings that affect other agents), Contracts (agreed function signatures / API interfaces), and Blocked (who is waiting on whom). Each agent reads this before starting and updates it as they work.
Conflict Resolution
Conflict Classification
Conflict Type
Description
Resolution
Additive
Both agents added different things to same file
Keep both, order logically
Semantic
Conflicting design decisions
Resolver agent evaluates both approaches
Structural
Same code modified differently (rename vs modify)
Escalate to human review
The Resolver Agent Pattern
When merge conflicts are too complex for heuristics, a dedicated resolver agent reviews:
Agent 1 output ──┐
├──> Resolver Agent ──> Unified output
Agent 2 output ──┘ |
v
"Agent 1's auth middleware is correct,
but Agent 2's error handling is better.
Combining both with Agent 1's structure
and Agent 2's try/catch pattern."
Real-World Multi-Agent Architectures
Tool
Isolation
Coordination
Max Agents
Cursor 2.0
Git worktrees per agent
Background agents, conflict detection
8
Claude Code Task
Isolated context per sub-agent
Parent/child, results summarized back
Unbounded
ccswarm
Git worktrees + Claude CLI
Template scaffolding, coordinator agent
Configurable
WinDAGs
ProcessExecutor / WorktreeExecutor
Wave-based (parallel within wave, serial across waves)
Per-wave
Resource Coordination Beyond Files
Port Management
# Using Port Daddy for port coordination
PORT_AUTH=$(pd claim auth-service -q) # Returns 3001
PORT_API=$(pd claim api-service -q) # Returns 3002
PORT_DB=$(pd claim test-database -q) # Returns 5433# Agents use claimed ports, no collisions
AGENT_1_CMD="AUTH_PORT=${PORT_AUTH} npm run dev:auth"
AGENT_2_CMD="API_PORT=${PORT_API} npm run dev:api"
Database Isolation
# Each agent gets its own test database
createdb "testdb_agent_${TASK_ID}"# Run migrations in isolation
DATABASE_URL="postgres://localhost/${TASK_ID}" npx prisma migrate deploy
# Cleanup after agent finishes
dropdb "testdb_agent_${TASK_ID}"
API Quota Coordination
Shared rate limiter across agents: maintain a global token budget, allocate fair shares per agent. When budget is low, each agent gets remaining / activeAgentCount tokens. Track per-agent usage to prevent any single agent from starving others.
Anti-Patterns
Anti-Pattern: Shared Working Directory
What it looks like: Multiple agents editing files in the same directory
Why wrong: Race conditions, overwritten changes, corrupted state
Instead: One worktree per agent, always.
Anti-Pattern: Optimistic Concurrency Without Merge Strategy
What it looks like: "Just let them all work, we'll merge later"
Why wrong: Merge conflicts scale quadratically with agent count; 8 agents can produce dozens of conflicts
Instead: Decompose tasks to minimize file overlap. Build the coupling matrix first.
Anti-Pattern: Coordinator Agent Bottleneck
What it looks like: One "manager" agent that reviews every decision from every worker agent
Why wrong: Serializes all work through one context window, negating parallelism
Instead: Coordinator sets contracts upfront, workers execute independently, coordinator reviews only at integration.
Anti-Pattern: No Dead Agent Detection
What it looks like: Agent crashes mid-task, its files stay locked, its worktree sits abandoned
Why wrong: Other agents can't claim those files, work stalls
Instead: Heartbeat mechanism. If no activity for N minutes, salvage the session (pd salvage).
Anti-Pattern: Ignoring Semantic Conflicts
What it looks like: All merges succeed (no git conflicts), but the code is broken
Why wrong: Git only detects textual conflicts, not logical ones (renamed function + caller of old name)
Instead: Run full test suite after every merge. Semantic conflicts show up as test failures.
Quality Checklist
[ ] Task decomposition analyzed for file overlap (coupling matrix)
[ ] Each agent has isolated worktree or sandbox
[ ] File claims registered (Port Daddy or equivalent)
[ ] Resource coordination in place (ports, databases, API quotas)
[ ] Message passing mechanism defined (events, shared doc, or notes)
[ ] Merge order determined by dependency graph
[ ] Conflict resolution strategy chosen (automated + escalation)
[ ] Dead agent detection and salvage process in place
[ ] Full test suite runs after integration merge
[ ] Semantic conflict detection beyond textual merge
[ ] Coordination overhead measured (<20% of total agent time)
[ ] Rollback plan: can revert any single agent's contribution
Core insight: The hardest part of multi-agent coordination is not the git mechanics -- it is decomposing work so that agents are truly independent. Time spent on task decomposition and coupling analysis saves 10x the time you would spend resolving conflicts.
