Solitaire: Open-Source Identity Layer for AI Agents Built with Claude Code

Solitaire is an open-source project that provides an identity layer for AI agents, built primarily using Claude Code as the development environment. Unlike agent memory tools that focus on recall, Solitaire addresses how agents work with users over time, aiming to move beyond what the creator describes as "a smart stranger with a better notebook."

Key Features and Architecture

The system has been in production since February, with the current version shaped by 600+ sessions and 15,700+ entries in real use. Key architectural decisions emerged from observing failure modes and fixing actual problems:

• MCP server architecture and hook system designed around how Claude Code handles tool calls and session state
• Retrieval weighting that adjusts based on what actually proved useful in practice
• Boot structure and persona compilation refined through production use
• Self-correcting knowledge graph with contradiction detection, confidence rescoring, and entity relinking
• Tiered boot context so agents arrive briefed rather than blank

Identity and Behavior System

Solitaire's identity system evolves through actual interaction rather than static configuration:

• Disposition traits (warmth, assertiveness, conviction, observance) compile from interaction patterns and evolve across sessions
• Persona and behavioral identity develops from real use, not config file editing
• Session residues carry forward how work felt, not just what was discussed
• New users get guided onboarding that builds the partner through conversation - pick a name, describe needs, and the system assembles persona from answers (no YAML required)

Local-First Design

The local-first approach is non-negotiable in the design:

• All storage is SQLite + JSONL in your workspace directory
• Zero network requests from the core engine
• No cloud dependency, no telemetry, no external API calls for memory operations
• Automatic rolling backups with no setup required
• Your data stays on your machine

Installation and Compatibility

Install via pip install solitaire-ai (note: not install solitaire, which is an unrelated package). The project is built for Claude Code first but supports other agent platforms. It's memory-agnostic - works with existing memory layers or provides one if needed.

License and Availability

Free and open source under AGPL-3.0, with commercial licensing available for proprietary embedding. Available on PyPI and the MCP Registry. Two research papers from the longitudinal work are currently in review.