mql-mcp 1.0.0

MQL4/MQL5 MCP server - 6 tools for docs lookup, code validation, and code generation

Complete MQL4/MQL5 reference documentation MCP server with 4853 entries covering 100% of the official MetaTrader 4/5 documentation sitemaps.

Quick Start | Tools | Configuration | Database | Development

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One Command. Two Minutes. Fully Functional.

pip install mql-mcp
mqlmcp

That's it. On first run, the server auto-builds the ChromaDB vector store from shipped JSON data (takes 30-60 seconds for embedding model download + indexing). Subsequent runs start instantly.

What you get:

• 6 MCP tools for MQL4/MQL5 docs lookup, code validation, and code generation
• 4853 entries indexed in a local ChromaDB vector store (100% offline)
• Sub-millisecond hot cache for priority lookups
• MetaEditor compiler integration (local, Wine, or SSH) for mql_compile
• MQL4-to-MQL5 automatic migration via mql_repair
• Works with Claude Desktop, Cursor, Windsurf, OpenCode, and any MCP client

What you need:

• Python 3.10+
• Any MCP-compatible AI client

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Why MQL MCP?

AI coding assistants hallucinate MQL syntax. MQL5 introduced significant changes from MQL4 (handle-based indicators, CTrade class, CopyBuffer pattern, event model) that models trained on older code get wrong.

MQL MCP gives AI assistants authoritative, real-time access to the complete MetaTrader 4/5 reference:

• 100% coverage: 4136/4136 MQL5 + 657/657 MQL4 sitemap URLs
• MQL4 + MQL5 unified: Single database with version tagging and filtering
• Semantic search: Vector embeddings find relevant docs by meaning, not keywords
• Real compilation: mql_compile validates code via the actual MetaEditor compiler
• MQL4 to MQL5 migration: mql_repair(mode="migrate") applies all known replacements
• Code generation: mql_scaffold generates validated EA, indicator, or script templates
• 100% local: No network calls at runtime (except optional compiler validation)

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Tools

+----------------------+---------------------------------------------+
| Tool                 | Description                                 |
+----------------------+---------------------------------------------+
| mql_lookup           | Get complete docs for a symbol by exact name|
| mql_search           | Semantic search across all MQL4/MQL5 docs   |
| mql_browse           | Enumerate all members of a namespace        |
| mql_compile          | Compile MQL code via MetaEditor or syntax   |
| mql_repair           | Fix compiler errors or migrate MQL4 to MQL5 |
| mql_scaffold         | Generate EA, indicator, or script template  |
+----------------------+---------------------------------------------+

Tool Details

mql_lookup(name, kind?, version?) Get complete documentation for an MQL symbol by exact name. Auto-detects function, variable, type, constant, keyword, or operator. Returns syntax, parameters, returns, remarks, and code examples. Filter by version="mql4" or version="mql5".

mql_search(query, category?, namespace?, n_results?, version?) Semantic search across the entire MQL4/MQL5 reference. Supports category filtering, namespace filtering, and version filtering.

mql_browse(namespace, category?, style?, version?) Enumerate every member of a namespace (e.g., trade, indicator, array). style="cheatsheet" produces a compact, box-drawn signature summary.

mql_compile(code?, file_path?, explain?, version?) Compile MQL code via the real MetaEditor compiler. Supports inline code, file paths, and explain=True for error-specific fix hints. Compilation methods (tried in order): local MetaEditor, remote SSH MetaEditor, syntax-only validation fallback.

mql_repair(code, context, mode?, version?) Fix compiler errors (mode="targeted") or migrate MQL4 code to MQL5 (mode="migrate"). Applies all known MQL4->MQL5 breaking change replacements, then recompiles to verify.

mql_scaffold(kind, name, description?, version?, lots?, take_profit?, stop_loss?, magic_number?) Generate a validated MQL EA, indicator, or script template. Pre-wired with standard inputs, risk parameters, and trade logic. Result is compiled before return.

MCP Client Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "mql-mcp": {
      "command": "mqlmcp",
      "transport": "stdio"
    }
  }
}

Cursor / Windsurf / OpenCode

Add to your project's .mcp.json or global MCP config:

{
  "mcpServers": {
    "mql-mcp": {
      "command": "mqlmcp",
      "transport": "stdio"
    }
  }
}

SSE (HTTP)

mqlmcp serve --transport sse --port 8080

Or via environment variable:

TRANSPORT=sse PORT=8080 mqlmcp

Connect to http://localhost:8080.

Configuration

+------------------------+---------------------+----------------------------------+
| Env Var                | Default             | Description                      |
+------------------------+---------------------+----------------------------------+
| TRANSPORT              | stdio               | Transport: stdio or sse          |
| PORT                   | 8080                | Port for SSE transport           |
| MQL_DB_PATH            | ./mql_db            | ChromaDB path                    |
| MQL_COLLECTION         | mql_reference       | ChromaDB collection name         |
| MQL_EMBED_MODEL        | all-MiniLM-L6-v2    | Sentence transformer model       |
| METAEDITOR_PATH        | (empty)             | Path to metaeditor64.exe         |
| METAEDITOR_SSH_HOST    | (empty)             | SSH host for remote compilation  |
| METAEDITOR_REMOTE_PATH | metaeditor64.exe    | Remote MetaEditor executable     |
| MQL_COMPILE_TIMEOUT    | 60                  | Compilation timeout in seconds   |
| LOG_LEVEL              | INFO                | Logging level                    |
| LAZY_MODEL             | 0                   | Set to 1 to defer model loading  |
+------------------------+---------------------+----------------------------------+

Database

• 4853 entries (MQL4 + MQL5 unified)
• MQL5: 4136/4136 sitemap URLs (100%)
• MQL4: 657/657 sitemap URLs (100%)
• 37 documentation sections + 33 MetaTrader5 Python API pages
• Hot cache for sub-millisecond priority lookups
• Auto-built on first run from shipped JSON data (7.5MB)

To rebuild the database:

mqlmcp build

Development

git clone https://github.com/TheFractalyst/mql-mcp.git
cd mql-mcp
pip install -e ".[dev]"
pytest tests/ -v

Re-scrape from MQL Docs

pip install -e ".[pipeline]"
python -m playwright install chromium
python pipeline/scrape_mql5.py
python pipeline/scrape_mql4.py
python pipeline/merge_and_index.py --reset --output-json data/mql_merged_entries.json

Docker

docker build -t mql-mcp .
docker run -p 8080:8080 -e TRANSPORT=sse mql-mcp

Tech Stack

• FastMCP 3.4 - MCP server framework with FileSystemProvider auto-discovery
• ChromaDB - Local vector database for semantic search (cosine, 384-dim)
• SentenceTransformers - all-MiniLM-L6-v2 embedding model
• RapidFuzz - Fuzzy string matching for name lookups
• Loguru - Structured logging with daily rotation (SSE mode)

Links

• fractalyst.dev - Portfolio
• MQL5 Documentation - Official MQL5 reference
• MetaTrader 5 - Trading platform
• @TheFractalyst - X / Twitter

License

MIT - see LICENSE