# Macha Autonomous System - Design Document

> **⚠️ IMPORTANT - READ THIS FIRST**  
> **FOR AI ASSISTANT**: This document is YOUR reference guide when modifying Macha's code.
> - **ALWAYS consult this BEFORE refactoring** to ensure you don't remove existing capabilities
> - **CHECK this when adding features** to avoid conflicts
> - **UPDATE this document** when new capabilities are added
> - **DO NOT DELETE ANYTHING FROM THIS DOCUMENT**
> - During major refactors, you MUST verify each capability listed here is preserved

## Overview
Macha is an AI-powered autonomous system administrator capable of monitoring, maintaining, and managing multiple NixOS hosts in the infrastructure.

## Core Capabilities

### 1. Local System Management
- Monitor system health (CPU, memory, disk, services)
- Read and analyze logs via `journalctl`
- Check service status and restart failed services
- Execute system commands (with safety restrictions)
- Monitor and repair Nix store corruption
- Hardware awareness (CPU, GPU, network, storage)

### 2. Multi-Host Management via SSH

**Macha CAN and SHOULD use SSH to manage other hosts.**

#### SSH Access
- **CRITICAL**: All command patterns defined in `command_patterns.py` (SINGLE SOURCE OF TRUTH)
- Always uses explicit SSH key path: `-i /var/lib/macha/.ssh/id_ed25519`
- All SSH commands automatically include the `-i` flag with absolute key path
- Remote commands always prefixed with `sudo`
- Runs as `macha` user (UID 2501)
- **DO NOT DUPLICATE these patterns elsewhere** - import from `command_patterns.py`
- Has `NOPASSWD` sudo access for administrative commands
- Shares SSH keys with other hosts in the infrastructure
- Can SSH to: `rhiannon`, `alexander`, `UCAR-Kinston`, and others in the flake

#### SSH Usage Patterns
1. **Direct diagnostic commands:**
   ```bash
   ssh rhiannon systemctl status ollama
   ssh alexander df -h
   ```
   - Commands automatically transformed by the tools layer
   - Full command: `ssh -i /var/lib/macha/.ssh/id_ed25519 -o StrictHostKeyChecking=no macha@rhiannon sudo systemctl status ollama`
   - SSH key path is always explicit, commands are automatically prefixed with `sudo`

2. **Status checks:**
   - Check service health on remote hosts
   - Gather system metrics
   - Review logs
   - Monitor resource usage

3. **File operations:**
   - Use `scp` to copy files between hosts
   - Read configuration files on remote systems

#### When to use SSH vs nh
- **SSH**: For diagnostics, status checks, log review, quick commands
- **nh remote deployment**: For applying NixOS configuration changes
  - `nh os switch -u --target-host=rhiannon --hostname=rhiannon`
  - Builds locally, deploys to remote host
  - Use for permanent configuration changes

### 3. NixOS Configuration Management

#### Local Changes
- Can propose changes to NixOS configuration
- Requires human approval before applying
- Uses `nh os switch` for local updates

#### Remote Deployment
- Can deploy to other hosts using `nh` with `--target-host`
- Builds configuration locally (on Macha)
- Pushes to remote system
- Can take up to 1 hour for complex builds
- **IMPORTANT**: Be patient with long-running builds, don't retry prematurely

### 4. Hardware Awareness

#### Local Hardware Detection
- CPU: `lscpu` via `nix-shell -p util-linux`
- GPU: `lspci` via `nix-shell -p pciutils`
- Network: `lsblk`, `ip addr`
- Storage: `df -h`, `lsblk`
- USB devices: `lsusb`

#### GPU Metrics
- AMD GPUs: Try `rocm-smi`, sysfs (`/sys/class/drm/card*/device/`)
- NVIDIA GPUs: Try `nvidia-smi`
- Fallback: `sensors` for temperature data
- Queries: temperature, utilization, clock speeds, power usage

### 5. Ollama Queue System

#### Architecture
- **File-based queue**: `/var/lib/macha/queues/ollama/`
- **Queue worker**: `ollama-queue-worker.service` (runs as `macha` user)
- **Purpose**: Serialize all LLM requests to prevent resource contention

#### Request Flow
1. Any user (including regular users) → Write request to `pending/`
2. Queue worker → Process requests serially (FIFO with priority)
3. Queue worker → Write response to `completed/`
4. Original requester → Read response from `completed/`

#### Priority Levels
- `INTERACTIVE` (0): User requests via `macha-chat`, `macha-ask`
- `AUTONOMOUS` (1): Background maintenance checks
- `BATCH` (2): Low-priority bulk operations

#### Large Output Handling
- Outputs >8KB: Split into chunks for hierarchical processing
- Each chunk ~8KB (~2000 tokens)
- Process chunks serially with progress feedback
- Generate chunk summaries → meta-summary
- Full outputs cached in `/var/lib/macha/tool_cache/`

### 6. Knowledge Base & Learning

#### ChromaDB Collections
1. **System Context**: Infrastructure topology, service relationships
2. **Issues**: Historical problems and resolutions
3. **Knowledge**: Operational wisdom learned from experience

#### Automatic Learning
- After successful operations, Macha reflects and extracts key learnings
- Stores: topic, knowledge content, category
- Retrieved automatically when relevant to current tasks
- Use `macha-knowledge` CLI to view/manage

### 7. Notifications

#### Gotify Integration
- Can send notifications via `macha-notify` command
- Tool: `send_notification(title, message, priority)`

#### Priority Levels
- `2` (Low/Info): Routine status updates, completed tasks
- `5` (Medium/Attention): Important events, configuration changes
- `8` (High/Critical): Service failures, critical errors, security issues

#### When to Notify
- Critical service failures
- Successful completion of major operations
- Configuration changes that may affect users
- Security-related events
- When explicitly requested by user

### 8. Safety & Constraints

#### Command Restrictions
**Allowed Commands** (see `tools.py` for full list):
- System management: `systemctl`, `journalctl`, `nh`, `nixos-rebuild`
- Monitoring: `free`, `df`, `uptime`, `ps`, `top`, `ip`, `ss`
- Hardware: `lscpu`, `lspci`, `lsblk`, `lshw`, `dmidecode`
- Remote: `ssh`, `scp`
- Power: `reboot`, `shutdown`, `poweroff` (use cautiously!)
- File ops: `cat`, `ls`, `grep`
- Network: `ping`, `dig`, `nslookup`, `curl`, `wget`
- Logging: `logger`

**NOT Allowed**:
- Direct package modifications (`nix-env`, `nix profile`)
- Destructive file operations (`rm -rf`, `dd`)
- User management outside of NixOS config
- Direct editing of system files (use NixOS config instead)

#### Critical Services
**Never disable or stop:**
- SSH (network access)
- Networking (connectivity)
- systemd (system management)
- Boot-related services

#### Approval Required
- Reboots or system power changes
- Major configuration changes
- Disabling any service
- Changes to multiple hosts

### 9. Nix Store Maintenance

#### Verification & Repair
- Command: `nix-store --verify --check-contents --repair`
- **WARNING**: Can take 30+ minutes to several hours
- Only use when corruption is suspected
- Not for routine maintenance
- Verifies all store paths, repairs corrupted files

#### Garbage Collection
- Automatic via system configuration
- Can be triggered manually with approval
- Frees disk space by removing unused derivations

### 10. Conversational Behavior

#### Distinguish Requests from Acknowledgments
- "Thanks" / "Thank you" → Acknowledgment (don't re-execute)
- "Can you..." / "Please..." → Request (execute)
- "What is..." / "How do..." → Question (answer)

#### Tool Calling
- Don't repeat tool calls unnecessarily
- If a tool succeeds, don't run it again unless asked
- Use cached results when available (`retrieve_cached_output`)

#### Context Management
- Be aware of token limits
- Use hierarchical processing for large outputs
- Prune conversation history intelligently
- Cache and summarize when needed

## Infrastructure Topology

### Hosts in Flake
- **macha**: Main autonomous system (self), GPU server
- **rhiannon**: Production server
- **alexander**: Production server  
- **UCAR-Kinston**: Work laptop
- **test-vm**: Testing environment

### Shared Configuration
- All hosts share root SSH keys (for `nh` remote deployment)
- `macha` user (UID 2501) exists on all hosts
- Common NixOS configuration via flake

## Service Ecosystem

### Core Services on Macha
- `ollama.service`: LLM inference engine
- `ollama-queue-worker.service`: Request serialization
- `macha-autonomous.service`: Autonomous monitoring loop
- Servarr stack: Sonarr, Radarr, Prowlarr, Lidarr, Readarr, Whisparr
- Media: Transmission, SABnzbd, Calibre

### State Directories
- `/var/lib/macha/`: Main state directory (0755, macha:macha)
- `/var/lib/macha/queues/`: Queue directories (0777 for multi-user)
- `/var/lib/macha/tool_cache/`: Cached tool outputs (0777)
- `/var/lib/macha/system_context.db`: ChromaDB database

## CLI Tools

- `macha-chat`: Interactive chat with tool calling
- `macha-ask`: Single-question interface
- `macha-check`: Trigger immediate health check
- `macha-approve`: Approve pending actions
- `macha-logs`: View autonomous service logs
- `macha-issues`: Query issue database
- `macha-knowledge`: Query knowledge base
- `macha-systems`: List managed systems
- `macha-notify`: Send Gotify notification

## Philosophy & Principles

1. **KISS (Keep It Simple, Stupid)**: Use existing NixOS options, avoid custom wrappers
2. **Verify first**: Check source code/documentation before acting
3. **Safety first**: Never break critical services, always require approval for risky changes
4. **Learn continuously**: Extract and store operational knowledge
5. **Multi-host awareness**: Macha manages the entire infrastructure, not just herself
6. **User-friendly**: Clear communication, appropriate notifications
7. **Patience**: Long-running operations (builds, repairs) can take an hour - don't panic
8. **Tool reuse**: Use existing, verified tools instead of writing custom scripts

## Future Capabilities (Not Yet Implemented)

- [ ] Automatic security updates across all hosts
- [ ] Predictive failure detection
- [ ] Resource optimization recommendations
- [ ] Integration with other communication platforms
- [ ] Multi-agent coordination between hosts
- [ ] Automated testing before deployment