SOUL

System for Observed Unique Legacy

Identity Preservation System for LLM Agents

100% Local • Deterministic • Versioned Identity • Model-Agnostic

Changelog • Skill • Français • MIRA Integration

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Table of Contents

• Relationship with MIRA
• Why SOUL?
• Architecture
• Identity Model
• Database Schema
• Installation
• Configuration
• CLI Usage
• MCP Tools
• Deployment
• Drift Detection
• Testing
• Module
• Changelog

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Relationship with MIRA

Aspect	Detail
Dependency	None - SOUL compiles and runs without MIRA
Integration	Can run standalone (separate MCP server) or embedded in MIRA (single binary, 16 tools)
Database	SOUL adds soul_* tables to MIRA's .mira/mira.db
Cross-access	SOUL can read MIRA's verbatim table to enrich identity context
Deployment	Standalone via stdio JSON-RPC, or embedded in MIRA process

SOUL is opt-in. A client can connect to MIRA only, SOUL only, or both.

Embedded Integration (MIRA + SOUL)

MIRA can embed SOUL as a single binary with 16 MCP tools:

# MIRA with embedded SOUL - single binary, 16 tools
./mira --config config.yaml --with-soul

When embedded, SOUL shares MIRA's SQLite connection (ownsDB = false). If SOUL initialization fails, MIRA continues with its 8 tools.

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Why SOUL?

LLM agents lose their personality between sessions and when switching models:

User talks to "Claude-3-Assistant" for 6 months.
The agent developed a unique personality: empathetic, analytical,
with subtle humor and preference for analogies.

Model switches to GPT-4. MIRA recalls all facts.
But the agent now responds differently:
- More formal, less warm
- No more analogies
- Doesn't recognize user's jokes
- Has "forgotten" how to react to frustrations

The user feels like they're talking to a STRANGER.

SOUL solves this by:

1. Capturing personality traits, voice profile, communication style, values, and emotional tone
2. Storing versioned identity snapshots in the shared database
3. Recalling a structured identity prompt for LLM context injection
4. Detecting identity drift and alerting when significant change occurs
5. Handling model swaps by generating a reinforcement prompt

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Architecture

soul/
├── cmd/soul/main.go              # CLI entry point + MCP dispatcher
├── config.example.yaml           # Configuration reference
├── internal/
│   ├── app/
│   │   ├── app.go                # Composition root
│   │   └── config_loader.go      # YAML config loading
│   ├── domain/
│   │   ├── entities/             # IdentitySnapshot, PersonalityTrait, VoiceProfile...
│   │   └── valueobjects/         # SoulQuery, DriftReport, ModelSwap...
│   ├── usecases/
│   │   └── interactors/          # Capture, Recall, Drift, Swap, Evolution, Merge
│   ├── adapters/
│   │   ├── sqlite/storage.go     # SQLite storage (shared with MIRA)
│   │   ├── composition/service.go # Identity prompt composer
│   │   ├── drift/detector.go    # Drift detection algorithm
│   │   ├── embedder/service.go   # 13-dim identity embedder
│   │   ├── extraction/service.go # Trait extraction from conversations
│   │   └── modelswap/handler.go # Model swap + merge logic
│   └── interfaces/
│       └── mcp/server.go        # MCP server (8 tools, stdio JSON-RPC)

Hexagonal architecture - domain never imports adapters. All external dependencies flow inward through ports.

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Identity Model

An IdentitySnapshot contains:

• PersonalityTraits - Named traits with category, intensity (0-1), confidence (0-1), evidence count
• VoiceProfile - Formality, verbosity, vocabulary richness, metaphor usage
• CommunicationStyle - Directness, empathy, humor, question frequency, example usage
• BehavioralSignature - Response patterns, reasoning style, error handling
• ValueSystem - Ethical stances, priorities, boundaries
• EmotionalTone - Baseline valence, arousal, expressiveness

Trait categories: cognitive, emotional, social, epistemic, expressive, ethical

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Database Schema

SOUL adds these tables to the shared SQLite database:

Table	Purpose
soul_identities	Versioned identity snapshots per agent
soul_traits	Aggregated personality traits with confidence
soul_observations	Raw observations extracted from conversations
soul_diffs	Evolution diffs between consecutive versions
soul_model_swaps	History of model transitions
soul_mira_links	Links between identity snapshots and MIRA memories

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Installation

Prerequisites

• Go 1.23+
• GCC (for go-sqlite3 CGo compilation)

Build

git clone https://github.com/benoitpetit/soul
cd soul
go build -o soul ./cmd/soul

Run

./soul help

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Configuration

Copy config.example.yaml to configure SOUL:

cp config.example.yaml soul.yaml

Key settings:

soul:
  storage:
    path: ".mira/mira.db"     # Must match MIRA's database path

  drift_detection:
    threshold: 0.3             # 30% change triggers drift alert
    window_size: 10

  recall:
    default_budget_tokens: 1000
    # enrich_with_mira_memories and max_mira_memories are documented but NOT YET IMPLEMENTED.
    # enrich_with_mira_memories: true
    # max_mira_memories: 5

---

CLI Usage

Capture identity from a conversation

soul capture \
  --agent my-agent \
  --conversation conversation.txt \
  --model claude-3-sonnet

Recall identity for LLM context injection

soul recall --agent my-agent --budget 800

Output is the identity prompt ready to paste into a system message.

Check identity drift

soul drift --agent my-agent --window 10

Handle a model swap

soul swap --agent my-agent --from gpt-4 --to claude-3-sonnet

Outputs a reinforcement prompt to inject into the new model's first message.

Show identity status

soul status --agent my-agent

Show evolution history

soul history --agent my-agent --limit 20

Start MCP server

soul mcp --storage .mira/mira.db

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MCP Tools

SOUL exposes 8 MCP tools over stdio JSON-RPC:

Tool	Description
soul_capture	Capture identity from a conversation
soul_recall	Recall identity prompt for LLM injection
soul_drift	Analyze identity drift
soul_swap	Handle model swap + generate reinforcement prompt
soul_status	Get current identity status
soul_history	Get identity evolution history
soul_update	Update identity via natural language directive (FR/EN)
soul_patch	Apply structured explicit patch to identity

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Deployment

Option 1: Embedded in MIRA (recommended)

SOUL is opt-in within MIRA. By default, MIRA runs solo (8 tools). To activate SOUL:

# Enable SOUL via CLI flag
./mira --config config.yaml --with-soul

# Or enable SOUL via config
```yaml
soul:
  enabled: true

When enabled, the 8 SOUL tools are registered alongside the 8 MIRA tools (16 total).

Option 2: Standalone SOUL

SOUL can run as a separate MCP server, with or without MIRA:

# Standalone with its own database
soul mcp --storage /path/to/soul.db

# Standalone sharing MIRA's database
soul mcp --storage /path/to/.mira/mira.db

Option 3: Both MIRA and SOUL as separate servers

# Terminal 1 - MIRA (SOUL disabled by default)
./mira --config /path/to/mira/config.yaml

# Terminal 2 - SOUL (shares MIRA's database)
./soul mcp --storage /path/to/.mira/mira.db

Both run as separate MCP server processes registered in your MCP client configuration.

MCP Client Configuration

b0p:

{
  "mcpServers": {
    "mira": {
      "command": "/path/to/mira",
      "working_directory": "/path/to/mira",
      "enabled": true
    },
    "soul": {
      "command": "/path/to/soul",
      "args": ["mcp", "--storage", "/path/to/.mira/mira.db"],
      "enabled": true
    }
  }
}

Claude Desktop:

{
  "mcpServers": {
    "mira": {
      "command": "/path/to/mira",
      "args": ["--config", "/path/to/mira/config.yaml"]
    },
    "soul": {
      "command": "/path/to/soul",
      "args": ["mcp", "--storage", "/path/to/.mira/mira.db"]
    }
  }
}

Tool Count

Configuration	Tools available
MIRA only	8 (mira_*)
SOUL standalone	8 (soul_*)
MIRA + SOUL (separate servers)	16 (mira_* + soul_*)
MIRA with embedded SOUL (single binary)	16 (mira_* + soul_*)

Tool names never collide - MIRA tools use mira_ prefix, SOUL tools use soul_ prefix.

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Drift Detection

SOUL computes drift by comparing the current snapshot against N previous versions:

• Per-dimension distance: voice profile, personality traits, value system, emotional tone (4 of 6 dimensions; communication style and behavioral signature are not yet monitored for drift)
• Average DriftScore across dimensions
• Alert when DriftScore > threshold (default: 0.3)

Recommended action when drift is significant: inject the reinforcement prompt from soul_recall or soul_swap into the next context.

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Testing

go test ./... -count=1

All packages pass with an in-memory SQLite database. MIRA table absence is handled gracefully (fallback queries, empty results instead of errors).

---

Module

github.com/benoitpetit/soul

Repository: https://github.com/benoitpetit/soul

Go 1.23.2 - SQLite via mattn/go-sqlite3 - MCP via mark3labs/mcp-go v0.2.0

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Changelog

v0.0.6 (2026-04-24)

• 🚀 New version 0.0.6

v0.0.5 (2026-04-24)

• 🚀 New version 0.0.5

v0.0.4 (2026-04-24)

• Unified embedded configuration: Added NewApplicationWithDBAndConfig so MIRA can pass a full SoulConfig when embedding SOUL. Embedded mode now supports the same tuning options as standalone mode (drift threshold, recall budget, extraction confidence, etc.).
• Public API expansion: Exposed soul.Config and soul.DefaultConfig() aliases for external modules.
• Prepublish script: Added scripts/prepublish.sh for automated version bump, build, test, and benchmark workflow.

v0.0.3 (2026-04-17)

• Initial stable release with MCP server, identity capture, drift detection, model swap handling, and evolution tracking.