Pi Dev Ops Model Farm

Pi-Dev-Ops Model Farm — Claude + OpenAI Hybrid Orchestrator

Overview

You have paid-tier access to:

• 3 × Claude Code (Max Plan) — unlimited usage via OAuth
• 1 × OpenAI Codex CLI (ChatGPT/Plus/Max) — flat-rate access

This skill turns those into a managed worker pool alongside Hermes' native OpenRouter models.

Architecture

                Hermes Session (OpenRouter)
                         |
                         v
                    Pi-Dev-Ops /nexus
                         |
        +----------------+----------------+
        |                |                |
        v                v                v
   [Flagship]    [Claude Farm]   [OpenAI Farm]
   Free models   (3 workers)     (1 worker)
   Kimi, Nemo    Claude OAuth    Codex CLI
   DeepSeek      via tmux        via tmux
        |                |                |
        +----------------+----------------+
                         |
                     Results IPC
                  (JSON-over-file)

Worker Definitions

Farm Operations

1. Spin Up Workers

Create a tmux session per worker that passes --print to avoid interactive prompts:

# Claude worker (non-interactive, pipe-ready)
tmux new-session -d -s claude-1 -x 120 -y 40 \
  'claude --print --permission-mode bypassPermissions --model claude-opus-5 "$@"'

# Codex worker
tmux new-session -d -s codex-1 -x 120 -y 40 \
  'codex exec --dangerously-auto-approve "$@"'

2. Dispatch Task to Worker

Write a JSON envelope to the worker's input pipe:

{
  "task_id": "uuid",
  "invoked_by": "pi-dev-ops/judge",
  "skill": "judge",
  "artefact_path": "D:/Pi-Dev-Ops/repo/src/auth.py",
  "prompt": "Full prompt text with all context",
  "output_format": "json|markdown|structured",
  "token_budget": 16000,
  "timeout_seconds": 300,
  "fallback_to": "claude-2"
}

Send via tmux:

# Write JSON to tmux stdin
echo '{"task_id":"abc","prompt":"..."}' > ~/.hermes/.farm/claude-1.in.json
# Trigger worker read
tmux send-keys -t claude-1 Enter

3. Collect Results

Worker logs symlink: ~/.hermes/.farm/<worker>.out.json

{
  "task_id": "abc",
  "completed_at": "2026-07-02T21:00:00Z",
  "status": "success|failure|timeout",
  "output": "...",
  "model_used": "claude-opus-5",
  "duration_seconds": 45,
  "tokens_used": {"prompt": 1200, "completion": 800},
  "tool_calls": 0
}

4. Health Monitor

Prometheus-style metrics file: ~/.hermes/.farm/metrics.jsonl

{"timestamp":"...","worker":"claude-1","latency_ms":450,"queue_depth":0,"status":"ready"}
{"timestamp":"...","worker":"codex-1","latency_ms":1200,"queue_depth":1,"status":"busy"}

Cron job every 60s:

cronjob(action="create", schedule="60s", prompt="Read ~/.hermes/.farm/metrics.jsonl. If any worker status != ready for >3 checks, restart via tmux. If total workers ready <2, alert.")

5. Circuit Breaker & Fallback

6. Cost Accounting

Since Claude Max and Codex are flat-rate, emit usage telemetry for visibility:

{
  "billing_type": "flat_rate",
  "monthly_cost_aud": 85.00,
  "claude_sessions_used": 3,
  "codex_sessions_used": 1,
  "tasks_dispatched": 47,
  "tasks_failed": 2,
  "total_tokens_consumed": {"claude": 120000, "codex": 45000},
  "openrouter_tokens_aved": 165000,
  "est_savings_aud": 35.00
}

Routing Matrix (Pi-Dev-Ops /nexus Integration)

The /nexus skill dispatches to the farm via this decision table:

Operational Commands

# List all farm workers
pi-dev-ops-farm status

# Restart a worker
pi-dev-ops-farm restart claude-1

# Force task to specific worker
pi-dev-ops-farm dispatch --worker claude-1 --task "Review this file" --file src/auth.py

# Scale workers up/down (dynamic range 1-3 per type)
pi-dev-ops-farm scale claude 3
pi-dev-ops-farm scale codex 1

# Emergency drain (finish in-flight, stop accepting new)
pi-dev-ops-farm drain

# Garbage-collect stale sessions
pi-dev-ops-farm gc

File Locations

Initialization Checklist

• All 3 Claude accounts logged in (claude auth login x3)
• Codex account logged in (codex login x1)
• Python 3.11+ available (python3 --version)
• claude CLI on PATH (Winget install)
• codex CLI on PATH (npm install -g @anthropic-ai/codex)
• Farm directory created (mkdir -p ~/.hermes/.farm)
• Run python3 model-farm.py --start to spin workers
• Test dispatch: write a .in-*.json task file and confirm result .out-*.json appears
• Hermes config updated with model_farm.enabled: true
• Cron health monitor set up if needed

Safety Rules

1. Never run destructive CLI commands (rm, git reset --hard, rm -rf) through claude/codex farm workers without Hermes-level approval.
2. Farm workers are READ-ONLY by default. Edit mode requires explicit --yolo or --dangerously-auto-approve flag set by Pi-Dev-Ops gate.
3. External-facing outputs from farm workers still get CEO/Board gate before delivery.
4. Credential isolation: farm workers have their own auth (OAuth); they never share API keys with Hermes/OpenRouter.

References

• Hermes terminal-orchestrator skill — tmux session management
• Hermes hermes-agent skill — CLI spawning patterns
• Claude Code CLI docs — claude --print, permission modes
• OpenAI Codex CLI docs — codex exec, --dangerously-auto-approve