DPSCoach – AI-Powered Combat Log Analyzer for Throne & Liberty

DPSCoach is a desktop application and MCP toolkit that parses Throne & Liberty combat logs into actionable DPS metrics, powered by a local AI coach that answers natural-language questions about your performance using SQL-first planning and DuckDB analytics. Prototype note: class-specific context is not wired yet; the class dropdown is intentionally disabled until backend class filtering is implemented. Fair-play disclaimer: This app only reads your exported text combat logs; it does not hook, modify, or automate the game client and does not confer any in-game advantage beyond offline analytics.

🎬 Demo

TODO: Record a 30-second GIF showing: log analysis → coach question → SQL trace → answer. See docs/DEMO.md for recording instructions.

Related MCP server: mcp-server-motherduck

✨ Features

• AI Coach with Intent Routing: Ask "Why did my crit rate drop?" and the coach detects intent (CRIT_BUCKET_TREND, SKILL_DELTA, RUNS, etc.) and routes to deterministic handlers or LLM-planned SQL queries.

• Single-Call MCP Analysis Packet: All metrics (run summary, top skills, timeline buckets, skill deltas, windows, action levers) returned in one get_analysis_packet call—no iterative prompting required.

• DuckDB Event Store: Combat events loaded into an in-memory DuckDB table for fast, safe, read-only SQL queries via MCP tools (query_dps, get_events_schema).

• Strict Model Verification: GGUF model integrity enforced via SHA-256 hash and minimum file size checks; models downloaded on-demand to user app data (never bundled).

• Read-Only Safety: All tools are SELECT-only; no INSERT/UPDATE/DELETE/file writes. Caps on result sizes (50 runs, 200 timeline buckets) prevent resource abuse.

• Deterministic Fallbacks: If the LLM misbehaves, the coach falls back to a safe default query and still produces an answer—never displays instructions to "use Quick Questions."

• PySide6 Desktop UI: Native Windows app with tabbed views (Summary, Runs, Skills, Coach) and background workers for non-blocking analysis.

• PyInstaller One-Click Build: Ships as a standalone EXE with Python runtime and all dependencies (except the GGUF model, which downloads on first launch).

• Class Context (coming soon): UI shows class dropdown today; backend class-filtered analysis will land in the next iteration.

• Fair Play: Reads UTF-8 combat log files only; no game hooks, memory reads, packet interception, or automation.

🏗️ Architecture

┌──────────────┐
│  PySide6 UI  │  (main.py)
│  (Desktop)   │
└──────┬───────┘
       │ QPushButton clicks
       ▼
┌──────────────────┐
│   SQLCoach       │  (coach_local.py)
│   Intent Router  │  ─ Detects RUNS, SKILLS, CRIT_BUCKET_TREND, etc.
│   + LLM Planner  │  ─ Plans SQL or returns deterministic answer
└──────┬───────────┘
       │ MCP client calls
       ▼
┌──────────────────┐
│  MCP Client      │  (mcp_client.py)
│  (Subprocess)    │  ─ Spawns `python -m mcp_server`
└──────┬───────────┘
       │ stdio JSON-RPC
       ▼
┌──────────────────┐
│  MCP Server      │  (mcp_server.py, FastMCP)
│  + DuckDB Store  │  ─ analyze_dps_logs, query_dps, get_analysis_packet
│  (event_store)   │  ─ Safe SELECT templates, no mutations
└──────┬───────────┘
       │ read logs
       ▼
┌──────────────────┐
│  Combat Logs     │  (UTF-8 .txt/.log files)
│  (TL SAVED dir)  │
└──────────────────┘

Key Design Choices:

• MCP as the contract boundary: UI and coach communicate via MCP tools, ensuring the same payload shape for CLI, desktop, and future integrations.

• Intent-first routing: Deterministic handlers (90% of questions) bypass the LLM entirely, guaranteeing consistent formatting and trace clarity.

• DuckDB instead of pandas: In-memory SQL engine enables ad-hoc queries without shipping raw events to the UI; query results are capped and safe.

🔒 Safety Guarantees

• Read-Only Tools: query_dps enforces SELECT-only via AST parse; INSERT/UPDATE/DELETE raise exceptions.

• Clamped Parameters: last_n_runs limited to [1, 50], top_k_skills to [1, 50], bucket_seconds coerced to allowed values (1, 2, 5, 10, 15, 30, 60).

• No File Writes in Tools: The MCP server never writes files; all outputs go to stdout (CLI) or returned as JSON (tools).

• Model Integrity: GGUF files must pass SHA-256 hash and minimum size checks before loading; corrupt or tampered models are rejected.

• Deterministic Self-Test: Model must respond "OK" to a trivial prompt before the UI enables the coach chat.

🎯 Engineering Signals (for hiring managers)

This project demonstrates professional software engineering practices suitable for production systems:

1. Contract-Driven Design

• MCP as API boundary: UI, CLI, and third-party clients consume identical JSON payloads.

• Stable schemas: runs_last_n normalized to list[dict] with explicit keys (run_id, dps, total_damage, etc.); consumers never rely on positional indexes.

• Test parity: Smoke tests (smoke_mcp_tool.py) verify MCP tool output matches CLI output (modulo generated_at timestamps).

2. Defensive Programming & Validation

• Input sanitization: SQL inputs quoted via .replace("'", "''"), user file paths resolved with Path(...).expanduser().

• Schema enforcement: Combat logs with unexpected column counts are skipped (not fatal); parsers yield instead of loading entire files into memory.

• Graceful degradation: Missing or corrupt models trigger fallback UIs; malformed LLM outputs route to deterministic handlers.

3. Testability & Observability

• 73 unit tests covering intent detection, route handlers, DPS bound checks, session persistence, skill delta rendering.

• Trace logging: Every coach answer includes a tool trace showing which MCP calls were made, with counts for runs/skills/timeline buckets.

• Reproducible builds: scripts/test_all.ps1 runs all tests + smoke checks in one command; CI/CD-ready.

4. Performance & Resource Management

• Streaming parsers: Log files parsed as iterators (yield per run) to avoid loading 100MB+ files into RAM.

• Background threads: Qt workers (QThread) for model downloads, analysis, and coach inference keep the UI responsive.

• DuckDB in-memory: Query results are row-limited and columnar; no unbounded memory growth.

5. Security & Isolation

• No shell=True: Model download uses urllib.request, MCP client spawns python -m mcp_server safely.

• Subprocess sandboxing: MCP server runs in a child process; UI never directly touches combat log files.

• User-controlled models: GGUF weights stored in %APPDATA%\DPSCoach\models\, never bundled in the EXE, so users verify/replace files independently.

6. User Experience & Polish

• Intent-aware routing: 90% of questions (RUNS, SKILLS, CRIT_BUCKET_TREND) skip the LLM and return instant, deterministic answers.

• Self-documenting UI: "Quick Questions" buttons demonstrate capabilities; SQL trace shows exactly what was queried.

• Transparent errors: Model validation failures display the exact error message; "Copy Error" button for support requests.

7. Maintainable Codebase

• Modular architecture: Parser (dps_logs/parser.py), metrics (metrics.py), reporting (reporting.py), server (server.py), UI (app/main.py) are independently testable.

• Type hints: All functions annotated with -> Dict[str, Any], Optional[str], etc.; mypy-compatible.

• Docstrings: Public APIs documented with Google-style docstrings; test names are descriptive (e.g., test_runs_analysis_dps_not_exceeding_bound).

🚀 Setup & Installation

Prerequisites

• Python 3.11+ (tested with Windows default install)

• Git (for cloning the repo)

• Throne & Liberty combat logs exported as UTF-8 .txt or .log files

Development Install

# Clone the repository
git clone https://github.com/stalcup-dev/tl-dps-mcp.git
cd tl-dps-mcp

# Install all dependencies (core + dev + UI + coach)
pip install -r requirements.txt

# Install coach-specific dependencies (llama-cpp-python)
pip install -r app/requirements_coach.txt

# Run CLI smoke test
python -m server --sample --pretty

# Run desktop app
python -m app.main

# (Optional) Showcase for data analytics skill growth
# - Swap log directories to compare player sessions and build a portfolio of analyses
# - Export JSON/MD outputs to demonstrate exploratory data analysis and reporting
# - Extend the MCP server with custom tools to highlight SQL + Python + DuckDB skills

Model Download

The desktop app will prompt to download the required GGUF model (~4.4 GB) on first launch. Models are stored at:

%APPDATA%\DPSCoach\models\model.gguf

Alternatively, download manually:

• Primary model: Qwen2.5-7B-Instruct Q4_K_M

• Place in models/model.gguf (repo root) or %APPDATA%\DPSCoach\models\model.gguf

Where Combat Logs Are Stored

Throne & Liberty saves logs to:

%LOCALAPPDATA%\TL\Saved\COMBATLOGS\

Point the UI or CLI at this directory to analyze your recent runs.

🧪 Running Tests

Official test contract (single command for all tests):

powershell -ExecutionPolicy Bypass -File .\scripts\test_all.ps1

Tip for your analytics portfolio: include the test contract in writeups to demonstrate reliability and reproducibility alongside your data insights.

This runs:

1. python -m unittest discover -s tests -v (73 unit tests)

2. python -m tests.smoke_mcp_tool --sample (MCP parity check)

Additional validation:

# Verify DPS math
python validate_output.py --sample

# Packaged build smoke test
python -m server --smoke-packaged

📖 Usage Examples

CLI Analysis

# Analyze bundled sample log
python -m server --sample --pretty

# Analyze your own logs (newest 5 runs)
python -m server --input-path %LOCALAPPDATA%\TL\Saved\COMBATLOGS --limit-runs 5 --output-json reports/latest.json --output-md reports/latest.md

# Smoke test (verifies MCP tools + DuckDB queries)
python -m server --smoke-packaged

CLI Options

MCP Tool (from Claude Desktop or other MCP clients)

Add to your MCP config (claude_desktop_config.json or similar):

{
  "mcpServers": {
    "tl-dps-mcp": {
      "command": "python",
      "args": ["-m", "mcp_server"],
      "cwd": "C:\\Users\\Allen\\Desktop\\Data Analyst Projects\\tl-dps-mcp"
    }
  }
}

Then ask Claude:

• "Analyze my TL logs at C:\Users...\COMBATLOGS"

• "What's my average DPS across the last 10 runs?"

• "Show me skill efficiency for run_123"

Desktop App Workflow

1. Launch python -m app.main

2. Click "Download Model" (one-time, ~4.4 GB)

3. After model self-test passes, click "Browse Combat Logs Directory"

4. Select your COMBATLOGS folder

5. Click "Analyze Logs"

6. Switch to Coach tab and ask questions like:

   • "Why did my crit rate drop?"

   • "Which skill fell off?"

   • "Show me my best run"

🗺️ Roadmap

• Multi-Run Comparisons: Side-by-side view of best vs. worst runs with delta highlights.

• Rotation Suggestions: Detect opener sequences and suggest reordering based on early damage frontloading.

• Benchmarks & Percentiles: Compare your DPS to class/spec benchmarks (user-submitted data or scraped leaderboards).

• Export Report: One-click PDF/HTML export with charts (DPS over time, skill breakdown pie chart, crit rate timeline).

• Performance Optimizations: Stream timeline buckets to SQLite on disk for sessions >1000 runs; add indexes for skill_name queries.

🙌 Help Wanted: Class Data

If you want to contribute, the biggest need is class reference data in plain text for every Throne & Liberty class:

• Class benefits and unique passives

• All skills with descriptions (damage types, DoT limits, cooldowns)

• Known combos/rotations and synergy notes

• Edge cases: caps on stacking or DoT application limits

Any text format works (TXT/MD/CSV). Drop links or files via an issue or PR so we can wire class-aware analysis faster.

📜 License

This project does not yet have a license file. A permissive open-source license (MIT or Apache 2.0) will be added before public release.

🙏 Acknowledgments

• Throne & Liberty by NCSoft for the combat log format.

• FastMCP for the Model Context Protocol server framework.

• DuckDB for the in-memory SQL engine.

• llama.cpp and llama-cpp-python for local GGUF inference.

• Qwen2.5-7B-Instruct (Alibaba) for the coach model weights.

📬 Contact & Links

• GitHub: github.com/stalcup-dev/tl-dps-mcp

• Author Email: allen.stalc@gmail.com

• Author GitHub: github.com/stalcup-dev

• Issues: github.com/stalcup-dev/tl-dps-mcp/issues

Built by a senior engineer who cares about contracts, testing, and user experience. 🚀