Version 1.4.2
Spawn Claude, Codex, AND Copilot from one coordinator. Your agents leave a paper trail.
A lightweight MCP server for cross-model AI agent orchestration. Works with Claude Code, GitHub Copilot, and any MCP-compatible client. Supports GPT, Claude, and Gemini models through multiple CLI providers.
PowerSpawn spawns real CLI agents (Claude Code, GitHub Copilot, Codex) that you already have installed. No API keys to manage separately - just use your existing subscriptions.
The MCP server wraps sub-agents and handles all logging deterministically. We don't rely on agents "following instructions" to update files - the orchestrator captures inputs/outputs automatically.
Hit Claude's rate limit? Spawn a Codex agent instead. PowerSpawn lets you balance work across multiple AI subscriptions, maximizing your throughput.
- CONTEXT.md - See which agents are currently running
- IAC.md - Complete audit trail of all inputs and outputs (newest first, last 15 entries)
File-based state means sessions can resume even after:
- Coordinator agent runs out of context window
- Process restarts or crashes
- Hours or days between work sessions
Multiple agents can work on different tasks simultaneously. The file-based architecture prevents conflicts and provides clear separation.
Sub-agents do the heavy lifting — reading files, searching code, running tests — and return concise summaries instead of raw data. Your coordinator's context stays lean, enabling:
- Longer sessions before hitting context limits
- More complex tasks within model constraints
- Better focus on orchestration, not file contents
| Feature | PowerSpawn | AutoGen | CrewAI | LangGraph |
|---|---|---|---|---|
| Cross-model spawning | Yes (Claude + Codex + Copilot) | No | No | No |
| Model diversity | GPT, Claude, Gemini | Limited | Limited | Limited |
| Uses existing CLI subscriptions | Yes | No | No | No |
| Deterministic logging | Yes | No | No | No |
| File-based persistence | Yes (IAC.md) | No | No | No |
| Context window optimization | Yes (summaries) | No | No | No |
| Zero infrastructure | Yes | Partial | Partial | No |
| MCP protocol native | Yes | No | No | No |
Traditional multi-agent systems use in-memory message passing or databases. PowerSpawn uses markdown files as the communication channel:
┌─────────────────────────────────────────────────────────────────┐
│ COORDINATOR (Claude/Copilot) │
│ Reads IAC.md, writes tasks │
└───────────────────────────┬─────────────────────────────────────┘
│
▼
┌─────────────────────────────┐
│ IAC.md │
│ • Task assignments │
│ • Agent results │
│ • Human-readable log │
│ • Git-trackable │
└─────────────────────────────┘
│
┌───────────────────┼───────────────────┐
▼ ▼ ▼
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ CODEX SUB-AGENT │ │ CLAUDE SUB-AGENT│ │COPILOT SUB-AGENT│
│ • GPT-5.1 │ │ • Claude models │ │ • GPT/Claude/ │
│ • Reads AGENTS │ │ • Reads CLAUDE │ │ Gemini models │
│ • Writes IAC.md │ │ • Writes IAC.md │ │ • Reads AGENTS │
└─────────────────┘ └─────────────────┘ └─────────────────┘
Why this matters:
- Auditable: Every agent interaction is logged in plain markdown
- Debuggable: Read IAC.md to see exactly what happened
- Persistent: Survives process restarts, session timeouts
- Version-controllable: Git tracks your agent history
We analyzed 900+ MCP repositories and major frameworks. Findings:
| Claim | Verified | Evidence |
|---|---|---|
| IAC.md pattern is novel | Yes | No equivalent found in existing repos |
| Cross-model orchestration is rare | Yes | Only 19 repos mention Claude + Codex together |
| MCP for agent spawning is uncommon | Yes | Most MCP servers are for external tools |
Closest competitor: claude-flow (1k stars) - but Claude-only, no cross-model support.
PowerSpawn is distributed as a git submodule - no package managers needed.
# Add as submodule
git submodule add https://github.com/CynaCons/PowerSpawn.git powerspawn
# Install Python dependencies
pip install mcpCopilot CLI uses PowerShell Core (pwsh) for shell commands on Windows. Without it, file operations (Create, Edit, Read) work, but shell commands fail.
# Install via winget
winget install Microsoft.PowerShell
# Verify installation
pwsh --version # Should show PowerShell 7.xNote: After installation, restart your terminal for PATH changes to take effect.
Claude Code (.mcp.json in project root):
{
"mcpServers": {
"agents": {
"command": "python",
"args": ["powerspawn/mcp_server.py"]
}
}
}GitHub Copilot (.vscode/mcp.json):
{
"servers": {
"powerspawn": {
"command": "python",
"args": ["powerspawn/mcp_server.py"],
"cwd": "${workspaceFolder}"
}
}
}git submodule update --remote powerspawnOnce configured, these MCP tools are available:
mcp__agents__spawn_claude - Spawn Claude sub-agent (haiku/sonnet/opus)
mcp__agents__spawn_codex - Spawn Codex sub-agent (GPT-5.1)
mcp__agents__spawn_copilot - Spawn Copilot sub-agent (GPT/Claude/Gemini)
mcp__agents__list - List running/completed agents
mcp__agents__result - Get agent result by ID
mcp__agents__wait_for_agents - Wait for all agents to complete
Example prompt:
"Can you powerspawn a Codex to run the test suite while you review the code?"
from spawner import spawn_claude, spawn_codex, spawn_copilot
# Spawn Claude for code review
result = spawn_claude("Review src/App.tsx for security issues")
# Spawn Codex for testing (preserves Claude rate limit)
result = spawn_codex("Run npm test and report failures")
# Spawn Copilot with any model (GPT, Claude, or Gemini)
result = spawn_copilot("Analyze this codebase structure", model="gpt-5.1")
result = spawn_copilot("Write documentation", model="gemini")powerspawn/
├── mcp_server.py # MCP server entry point (~500 lines)
├── spawner.py # Core spawn logic for Claude/Codex
├── logger.py # IAC.md logging with file locking
├── context_loader.py # Example: future role-based context (not currently used)
├── parser.py # Response parsing (JSON, JSONL)
├── __init__.py # Package exports
├── requirements.txt # Python dependencies (just 'mcp')
├── schemas/ # JSON output schemas
├── examples/ # Usage examples
├── site/ # Landing page (powerspawn.com)
├── README.md # This file
├── MCP_DESIGN.md # Detailed architecture docs
└── DESIGN.md # Original design document
Auto-generated files (gitignored):
IAC.md- Inter-Agent Communication logCONTEXT.md- Active agent status
PowerSpawn relies on the CLI tools' built-in context loading:
| Agent | CLI | Auto-loads |
|---|---|---|
| Claude | claude |
CLAUDE.md from project root |
| Codex | codex |
AGENTS.md from project root |
| Copilot | copilot |
AGENTS.md from project root |
These files should contain:
- Project structure overview
- Key file locations
- Current sprint/iteration goals
- Role guidelines (do's and don'ts)
The coordinator writes task assignments here. Agents read instructions and append results. Format:
## Task: Run Production Tests
**Assigned to:** Codex
**Status:** In Progress
**Timestamp:** 2025-12-01T20:30:00
### Instructions
Run `npm run test:production` and report any failures...
### Result
[Agent appends result here when complete]Auto-loaded by Codex CLI. Defines:
- Available tools and restrictions
- Output format expectations
- Project conventions
- Do's and don'ts
Auto-generated by PowerSpawn. Shows currently running agents (resets on server restart).
{
"prompt": "Your task description",
"model": "sonnet", // haiku | sonnet | opus
"timeout": 600 // seconds (default: 600)
}{
"prompt": "Your task description"
}{
"prompt": "Your task description",
"model": "gpt-5.1" // gpt-5.1 | gpt-5 | gpt-5.1-codex | gpt-5-mini |
// claude-sonnet | claude-haiku | claude-opus | gemini
}Available models:
| Model | Provider | Description |
|---|---|---|
gpt-5.1 |
OpenAI | GPT-5.1 (default) |
gpt-5 |
OpenAI | GPT-5 |
gpt-5.1-codex |
OpenAI | Optimized for code |
gpt-5-mini |
OpenAI | Fast, lightweight |
claude-sonnet |
Anthropic | Claude Sonnet 4.5 |
claude-haiku |
Anthropic | Claude Haiku 4.5 |
claude-opus |
Anthropic | Claude Opus 4.5 |
gemini |
Gemini 3 Pro Preview |
Returns running and completed agent IDs.
{
"agent_id": "abc123"
}Returns the agent's output, cost, and status.
Blocks until all running agents complete. Returns all results.
Coordinator: "Spawn Codex to run tests while I review the PR"
→ Codex runs tests (doesn't consume Claude rate limit)
→ Claude reviews code
→ Both results collected
Coordinator: "Powerspawn an Opus agent to research multi-agent patterns"
→ Opus agent does deep research with web search
→ Results written to IAC.md
→ Coordinator summarizes findings
Coordinator: "Spawn 4 agents to migrate different test file groups"
→ Agent 1: tests/editor/01-10
→ Agent 2: tests/editor/11-20
→ Agent 3: tests/editor/21-30
→ Agent 4: tests/editor/31-40
→ All run in parallel, results collected
Environment variables:
ANTHROPIC_API_KEY- For Claude agentsOPENAI_API_KEY- For Codex agents
Agent defaults are in the MCP server. Override via tool parameters.
For a comprehensive understanding of PowerSpawn's architecture and the reasoning behind our design decisions, read DESIGN.md.
Key highlights:
- Why deterministic logging? Agents are 95% unreliable at self-reporting (Section 6.1)
- Layered supervision model - User → Coordinator → Python → Sub-agents (Section 2.3)
- The Determinism Principle - Everything that CAN be done deterministically SHOULD be (Section 2.1)
- Agent capability matrix - When to use Claude vs Codex (Section 11)
- Landing page at powerspawn.com
- GitHub Copilot integration (spawn_copilot)
- Support for Gemini models (via Copilot CLI)
- MCP Registry submission
- Unit and integration test suite
MIT - Use it, fork it, improve it.
Built with AI, for AI orchestration.
Part of the PowerTimeline project.