MCP Reasoning Server

An MCP server that adds structured reasoning capabilities to Claude Code and Claude Desktop.

Features

Structured Reasoning - Linear, tree-based, and graph-based reasoning patterns
Decision Analysis - Weighted scoring, pairwise comparison, TOPSIS, stakeholder mapping
Bias Detection - Identify cognitive biases and logical fallacies in arguments
Counterfactual Analysis - What-if scenarios using Pearl's causal framework
Session Persistence - Save and restore reasoning state across sessions
Built-in Workflows - Pre-configured presets for common reasoning tasks
Self-Improvement - 4-phase optimization loop (Monitor → Analyze → Execute → Learn) with circuit breaker safety

Architecture

┌─────────────┐     stdin      ┌─────────────────┐
│ Claude Code │───────────────▶│   MCP Server    │──────▶ Anthropic API
│ or Desktop  │◀───────────────│     (Rust)      │
└─────────────┘     stdout     └────────┬────────┘
                                        │
                                        ▼
                                     SQLite

Installation

Prerequisites

Rust 1.75+ (for async traits)
Anthropic API key

Build from Source

git clone https://github.com/quanticsoul4772/mcp-reasoning.git
cd mcp-reasoning
cargo build --release

The binary will be at target/release/mcp-reasoning.

Configuration

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | ANTHROPIC_API_KEY | Yes | - | Your Anthropic API key | | DATABASE_PATH | No | ./data/reasoning.db | SQLite database path | | LOG_LEVEL | No | info | Logging level (error/warn/info/debug/trace) | | REQUEST_TIMEOUT_MS | No | 30000 | Request timeout in milliseconds | | MAX_RETRIES | No | 3 | Maximum API retry attempts |

Claude Code Integration

claude mcp add mcp-reasoning \
  --transport stdio \
  --env ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY \
  -- /path/to/mcp-reasoning

Claude Desktop Integration

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "mcp-reasoning": {
      "command": "/path/to/mcp-reasoning",
      "env": {
        "ANTHROPIC_API_KEY": "sk-ant-xxx"
      }
    }
  }
}

The 15 Reasoning Tools

Core Reasoning (6 tools)

| Tool | Description | |------|-------------| | reasoning_linear | Sequential step-by-step reasoning with confidence scoring | | reasoning_tree | Branching exploration (create/focus/list/complete) | | reasoning_divergent | Multi-perspective generation with force_rebellion mode | | reasoning_reflection | Meta-cognitive analysis (process/evaluate) | | reasoning_checkpoint | State management (create/list/restore) | | reasoning_auto | Automatic mode selection based on content |

Graph Reasoning (1 tool)

| Tool | Description | |------|-------------| | reasoning_graph | Graph-of-Thoughts with 8 operations: init, generate, score, aggregate, refine, prune, finalize, state |

Analysis Tools (3 tools)

| Tool | Description | |------|-------------| | reasoning_detect | Cognitive bias and logical fallacy detection | | reasoning_decision | Decision analysis (weighted/pairwise/topsis/perspectives) | | reasoning_evidence | Evidence evaluation with Bayesian updates |

Advanced Reasoning (3 tools)

| Tool | Description | |------|-------------| | reasoning_timeline | Temporal reasoning (create/branch/compare/merge) | | reasoning_mcts | Monte Carlo Tree Search with UCB1 exploration | | reasoning_counterfactual | What-if analysis using Pearl's Ladder of Causation |

Infrastructure (2 tools)

| Tool | Description | |------|-------------| | reasoning_preset | Pre-defined reasoning workflows (list/run) | | reasoning_metrics | Usage metrics and observability |

Usage Examples

Linear Reasoning

{
  "tool": "reasoning_linear",
  "arguments": {
    "content": "Analyze the trade-offs between microservices and monolithic architectures",
    "confidence": 0.8
  }
}

Tree Exploration

{
  "tool": "reasoning_tree",
  "arguments": {
    "operation": "create",
    "content": "What are the best approaches to handle user authentication?",
    "num_branches": 3
  }
}

Divergent Perspectives

{
  "tool": "reasoning_divergent",
  "arguments": {
    "content": "Should we migrate to a new database technology?",
    "num_perspectives": 4,
    "force_rebellion": true
  }
}

Decision Analysis

{
  "tool": "reasoning_decision",
  "arguments": {
    "type": "weighted",
    "question": "Which cloud provider should we choose?",
    "options": ["AWS", "GCP", "Azure"]
  }
}

Counterfactual Analysis

{
  "tool": "reasoning_counterfactual",
  "arguments": {
    "scenario": "Our startup chose Python for the backend",
    "intervention": "What if we had chosen Rust instead?",
    "analysis_depth": "counterfactual"
  }
}

Built-in Presets

| Preset | Category | Description | |--------|----------|-------------| | code-review | CodeQuality | Analyze code with bias detection and alternative approaches | | debug-analysis | Analysis | Hypothesis-driven debugging with evidence evaluation | | architecture-decision | Decision | Multi-factor architectural decision making | | strategic-decision | Decision | Stakeholder-aware strategic planning with risk assessment | | evidence-conclusion | Research | Evidence-based research synthesis |

Run a preset:

{
  "tool": "reasoning_preset",
  "arguments": {
    "operation": "run",
    "preset_id": "code-review",
    "inputs": {
      "code": "function example() { ... }"
    }
  }
}

Development

Build Commands

# Debug build
cargo build

# Release build
cargo build --release

# Run tests
cargo test

# Check formatting
cargo fmt --check

# Run clippy lints
cargo clippy -- -D warnings

# Run with coverage (requires cargo-llvm-cov)
cargo llvm-cov --fail-under-lines 100

Project Structure

src/
├── main.rs              # Entry point
├── lib.rs               # Module declarations
├── traits.rs            # Core traits (AnthropicClientTrait, StorageTrait)
├── error/               # Error types
├── config/              # Configuration
├── anthropic/           # Anthropic API client
├── storage/             # SQLite persistence
├── prompts/             # Mode-specific prompts
├── modes/               # Reasoning mode implementations
├── server/              # MCP server infrastructure
├── presets/             # Built-in workflow presets
├── metrics/             # Usage metrics
└── self_improvement/    # Self-optimization system

Code Quality

Zero unsafe code (#![forbid(unsafe_code)])
No panics in production paths
100% test coverage enforced
Max 500 lines per file
Structured logging via tracing

License

MIT

Contributing

Fork the repository
Create a feature branch
Ensure all tests pass with cargo test
Ensure clippy passes with cargo clippy -- -D warnings
Submit a pull request

Acknowledgments

Built on the rmcp MCP SDK
Inspired by structured reasoning research and Graph-of-Thoughts

MCP Servers