GeneXus 18 MCP Server (Genexus18MCP)

A high-performance Model Context Protocol (MCP) server for GeneXus 18. It integrates native GeneXus SDK access via a .NET 8 gateway and a .NET Framework 4.8 worker, exposing direct read/write/analysis operations directly to AI Agents and IDEs.

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🚀 Quick Start (Installation & Configuration)

You do NOT need to clone this repository, and you do NOT need to install anything globally via npm i -g. The standard Node.js npx runner will dynamically fetch and launch the compiled gateway for you.

Step 1: Configure (Non-Interactive First)

To initialize configuration in a deterministic, agent-friendly way:

npx genexus-mcp@latest init --kb "C:\KBs\YourKB" --gx "C:\Program Files (x86)\GeneXus\GeneXus18"

If you want the setup wizard prompts explicitly, run:

npx genexus-mcp@latest init --interactive

Step 2: Restart your AI Assistant

Once the wizard outputs 🎉 You are all set!, simply Restart or Refresh your AI Assistant (Claude Desktop, Antigravity, Cursor, etc.). The AI will automatically spin up the server in the background and connect.

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🤖 Auto-Installer Prompt (Copy & Paste to your AI)

If you want your AI Assistant to install and configure everything itself without you touching the terminal, copy and paste this exact prompt into your chat window:

Please configure your Model Context Protocol (MCP) server to connect to my GeneXus Knowledge Base by following these exact steps:

1. Run the command `npx genexus-mcp@latest init` directly in the terminal in non-interactive mode using this configuration format (do not use interactive prompts). You must inject my raw KB path and GX path via environment variables or a direct config patch if needed, or simply let the zero-config auto-discovery handle it if we are already in the KB folder.
2. If I haven't told you my GeneXus path or KB path, STOP and ask me for them now.
3. Once the setup is complete, read the generated JSON block from the console output.
4. If you use a global configuration file (like `mcp_config.json` or `claude_desktop_config.json`), insert the exact `mcpServers` block provided in the console output. Use `npx.cmd` as the command.
5. Provide a summary of the installation and notify me when you are ready to query GeneXus!

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AXI CLI Commands

The package now includes agent-facing commands optimized for shell automation:

genexus-mcp home
genexus-mcp axi home
genexus-mcp llm help
genexus-mcp status
genexus-mcp doctor --mcp-smoke
genexus-mcp tools list
genexus-mcp config show
genexus-mcp layout status
genexus-mcp layout run --action activate-layout
genexus-mcp layout run --action activate-tab --tab "Layout"
genexus-mcp layout inspect --tab "Layout"

Global AXI flags:

• --format toon|json|text (default for AXI commands: toon)
• --fields f1,f2,... (minimal schema by default; request extra fields explicitly)
• --limit <n> (for list commands)
• --query <text> (for tools list)
• --full (expand truncated long-form content when supported)
• --mcp-smoke (for doctor; executes protocol smoke checks)
• --quiet and --no-color (agent-safe output control)

Layout automation flags (layout run):

• --action focus|activate-layout|activate-tab|send-keys|type-text|click
• --title "<window-title-fragment>" to target a specific GeneXus window
• --tab "<tab-name>" for activate-tab
• --keys "<sendkeys-pattern>" for send-keys
• --text "<text>" for type-text
• --x <screenX> --y <screenY> for click

Layout inspection:

• genexus-mcp layout inspect [--tab "<tab-name>"] [--limit N] [--full] [--title "<window-title-fragment>"]
• Returns UI Automation controls with bounding rectangles (bounds.x/y/width/height) to support deterministic replay.

Notes:

• Structured data/errors are emitted on stdout.
• Diagnostic/progress output stays on stderr.
• meta.command is always present for stable command identity in AXI outputs.
• Use genexus-mcp <command> --help for command-specific usage/examples.
• Output metadata includes meta.schemaVersion for contract stability.
• --fields is validated strictly per command; invalid fields return usage_error and exit code 2.
• Running genexus-mcp without an AXI subcommand keeps the original MCP gateway launcher behavior.
• genexus-mcp home (genexus-mcp axi home) is the explicit content-first AXI entrypoint.
• genexus-mcp llm help returns protocol-first usage guidance for agents.
• Full LLM-facing AXI contract: docs/axi_cli_contract.md
• LLM usage playbook (CLI + MCP best practices): docs/llm_cli_mcp_playbook.md

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🛠️ Tool Surface (Skills)

(See GEMINI.md for extended guidelines). The worker natively exposes the following tools to the MCP Router:

• Search & Discovery: genexus_query, genexus_read, genexus_inspect, genexus_list_objects, genexus_properties
• Editing & Architecture: genexus_edit, genexus_create_object, genexus_refactor, genexus_forge
• Analysis: genexus_analyze, genexus_inject_context, genexus_doc, genexus_explain_code, genexus_summarize
• File System & Assets: genexus_asset, genexus_export_object, genexus_import_object
• History & DB: genexus_history, genexus_get_sql, genexus_structure
• Native Layout SDK: genexus_layout (get_tree, find_controls, set_property, set_properties, rename_printblock, add_printblock, get_preview, scan_mutators)

genexus_edit modes: xml (default — full XML replacement), ops (typed semantic op catalog: set_attribute, add_attribute, remove_attribute, add_rule, remove_rule, set_property), patch (JSON-Patch RFC 6902 array over canonical JSON object; legacy string-form patch also accepted for backward compatibility).

All write tools accept dryRun: true (returns a preview plan envelope without mutating the KB) and idempotencyKey (safe retries — concurrent calls with same key are coalesced; results cached for 15 min by default).

Layout color note:

• For ForeColor, BackColor, BorderColor, send color values as palette names (Black, Blue, Red, Transparent) or RGB token (R; G; B|) to avoid nested SDK wrappers.
• Lifecycle & Build: genexus_lifecycle, genexus_test, genexus_format
• Patterns: Smart XML generation and interpretation (e.g., WorkWithPlus PatternInstance mapping).

MCP tool response ergonomics

For tools/call, the gateway keeps MCP compatibility and adds lightweight response metadata:

• _meta.schemaVersion currently mcp-axi/2
• _meta.tool with the normalized tool name
• collection helpers such as returned, total, empty, and (when inferable) hasMore and nextOffset
• truncation signals via _meta.truncated plus contextual help
• _meta.idempotent: true on cache-hit responses
• _meta.batched: true on targets[] multi-object responses
• _meta.dryRun: true on dry-run preview responses
• _meta.removedTools advertised on initialize for proactive agent detection of removed tools

For list-heavy calls (genexus_query, genexus_list_objects), optional arguments can reduce token usage:

• fields: explicit projection (["name","type"] or "name,type")
• axiCompact: true: compact default projection

Timeout behavior for long-running MCP tools:

• Gateway may return result.isError=true with status=Running plus operationId/correlationId.
• In this case, do not fail fast. Continue with genexus_lifecycle(action='status'|'result', target='op:<operationId>').

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💻 Development & Building from Source

If you want to contribute, build the project yourself, or use the local Nexus-IDE VS Code Extension, use the classic source-based workflow.

Automated Release (npm + GitHub)

• Workflow: .github/workflows/release.yml
• Trigger: push na main com mudança em package.json
• Behavior:
• compara a versão atual com a versão do commit anterior
• publica no npm apenas se a versão for nova
• cria GitHub Release com tag v<version>
• Required secret:
• NPM_TOKEN (token de publicação no npm com permissão para o pacote genexus-mcp)

One-Click Build

1. Clone the repository to your Windows machine.
2. Run .\setup.bat.
   • This checks prerequisites, builds the C# components, and auto-registers the local server with Claude, Codex, Antigravity, and Cursor when detected.
3. If GeneXus or your KB are not auto-detected, follow the terminal prompts.

Nexus-IDE (VS Code)

The repository includes src/nexus-ide, a lightweight VS Code extension containing:

• Virtual file system using the genexus:// scheme
• Dynamic KB explorer with multi-part editing (Source, Rules, Events, Variables)
• Built-in MCP discovery commands (tools, resources, prompts)

Advanced Configuration

You can expand your local config.json for advanced networking or timeouts:

{
  "Server": {
    "HttpPort": 5000,
    "BindAddress": "127.0.0.1",
    "SessionIdleTimeoutMinutes": 10,
    "WorkerIdleTimeoutMinutes": 5
  },
  "GeneXus": {
    "InstallationPath": "C:\\Program Files (x86)\\GeneXus\\GeneXus18",
    "WorkerExecutable": "worker\\GxMcp.Worker.exe"
  },
  "Environment": {
    "KBPath": "C:\\KBs\\YourKB"
  }
}

Process Lifecycle & Architecture

• Lazy Worker Mapping: The .NET 8 Gateway is resident, but the heavy .NET 4.8 Worker is lazy (only spins up when the first standard command is received) and automatically terminates after Server.WorkerIdleTimeoutMinutes of inactivity to unlock build artifacts.
• Gateway Reuse: Launching multiple local IDE instances reuses a single active gateway using a unique lease file located at %LOCALAPPDATA%\GenexusMCP\gateway-leases.
• HTTP Mode: Run via HTTP at http://127.0.0.1:5000/mcp (Supports SSE notifications alongside standard POST JSON-RPC). Protocol expects MCP-Protocol-Version: 2025-06-18.

graph LR
    A[AI Client or Nexus-IDE] -->|MCP stdio or HTTP /mcp| B[Gateway .NET 8]
    B -->|JSON-RPC over process boundary| C[Worker .NET Framework 4.8]
    C -->|Native SDK| D[GeneXus KB]