Nette MCP Inspector

MCP (Model Context Protocol) server for Nette application introspection. Allows AI assistants to inspect your Nette application's DI container, database schema, routing, and more.

⚠️ Development tool only. Inspector exposes the project's full DI graph and configuration (sensitive keys are masked on a best-effort basis only). It refuses to start against an application running in production mode; override with MCP_INSPECTOR_ALLOW_PRODUCTION=1 only if you fully understand the exposure.

Installation

With Claude Code and the Nette plugin:

/install-mcp-inspector

Or manually:

composer require nette/mcp-inspector

After installation, restart Claude Code session to activate the MCP server.

Available Tools

DI Container

Tool	Description
di_get_services	List all registered services as name → type, filterable
di_get_service	Get details of a specific service (type, tags, instantiation status)
di_get_parameter_names	List all parameter names (nested values flattened to dotted notation)
di_get_parameter	Read a single parameter by name (sensitive masking, Windows path normalization)
di_get_aliases	List service aliases as alias → canonical name map
di_find_by_tag	Find services by tag
di_find_by_type	Find services implementing a type/interface (with autowired flag)

Database

Tool	Description
db_get_tables	List all database tables
db_get_columns	Get columns of a specific table (types, nullable, primary key, foreign keys)
db_get_relationships	Get foreign key relationships between all tables (belongsTo, hasMany)
db_get_indexes	Get indexes for a table
db_explain_query	Run EXPLAIN on a SELECT query (read-only, safe)
db_generate_entity	Generate PHP entity class code for a table

Router

Tool	Description
router_get_routes	List all registered routes with masks and defaults
router_match_url	Match URL to presenter/action (e.g., "/article/123")
router_generate_url	Generate URL for presenter/action (e.g., "Article:show")

Tracy Debugger

Tool	Description
tracy_get_last_exception	Get last logged exception with details
tracy_get_exceptions	List recent exception files
tracy_get_exception	Get full details of a specific exception by HTML filename
tracy_get_warnings	Get recent PHP warnings
tracy_get_log	Get entries from any Tracy log level

Configuration

The inspector requires a single file in your project root: mcp-bootstrap.php. It must return a Closure that produces a fully built Nette\DI\Container. The script is responsible for requiring its own autoloader.

Live config reload

The bridge invokes the closure on every tool call, so config edits in common.neon, services.neon, etc. are picked up live — no need to restart Claude Code or the MCP server. Nette caches the compiled container on disk and reuses it when configs are unchanged, so the per-call overhead is just a metadata check and a require.

In auto-rebuild mode (debug), Nette also handles the long-running-process case where PHP cannot redeclare an already-loaded class: when configs change, Nette generates a uniquely-named copy of the new container into memory via eval() (gated behind autoRebuild=true, never used in production). This requires nette/di ≥ 3.2 with the live-reload patch.

If a rebuild fails (e.g. a typo in your config), the bridge keeps serving the last-known-good container and adds a _warning field to tool results so you immediately see the failure message and the container source.

Standard skeleton

For Nette Web Project where App\Bootstrap::boot() is static:

<?php declare(strict_types=1);
require __DIR__ . '/vendor/autoload.php';
return fn() => App\Bootstrap::boot()->createContainer();

Custom bootstrap

When App\Bootstrap has an instance constructor (multi-tenant, parameterized blogs etc.), delegate to it through an instance — but keep the new Configurator call inside the existing Bootstrap class so Nette's %appDir% autodetection (based on the file where new Configurator is invoked) resolves correctly:

<?php declare(strict_types=1);
require __DIR__ . '/vendor/autoload.php';
return fn() => (new App\Bootstrap(App\Blog::LaTrine))->bootConsoleApplication();

CLI flags

mcp-inspector [--project=PATH] [--bootstrap=PATH]

• --project=PATH — project root (defaults to current working directory)
• --bootstrap=PATH — alternate bootstrap script (defaults to <project>/mcp-bootstrap.php)

Creating Custom Toolkits

Custom toolkits live in your project's code and are auto-discovered from the DI container. Implement the Toolkit marker interface and register the class as a service:

namespace App\Mcp;

use Mcp\Capability\Attribute\McpTool;
use Nette\McpInspector\Toolkit;

class BlogToolkit implements Toolkit
{
    public function __construct(
        private BlogFacade $blogs,
    ) {}

    /**
     * Get blog post by ID.
     * @param int $id Post ID
     */
    #[McpTool(name: 'blog_get_post')]
    public function getPost(int $id): array
    {
        $post = $this->blogs->getPost($id);
        return $post ? ['id' => $post->id, 'title' => $post->title] : ['error' => 'not found'];
    }
}

# services.neon
services:
    - App\Mcp\BlogToolkit

ServerFactory finds it via Container::findByType(Toolkit::class) — no extra registration needed. Standard Nette DI handles dependency injection.

Overriding a built-in toolkit

A project toolkit registered via services.neon automatically overrides a built-in of the same kind when it is instanceof it:

namespace App\Mcp;

use Nette\McpInspector\Toolkits\DIToolkit;

// extends the built-in DIToolkit → replaces it entirely
class MyDIToolkit extends DIToolkit { /* extra tools or overrides */ }

ServerFactory registers project toolkits first, then skips any built-in whose class is already covered by a project instance. Project toolkits that don't extend a built-in (a fresh implements Toolkit) coexist with all defaults.

For built-in toolkits that ship with MCP Inspector itself, see CLAUDE.md — they take a ContainerAccessor (not a Container) and re-resolve services per call so live config reload works. Project toolkits registered via services.neon are constructed once at server startup; if you need config-reload semantics for a project toolkit too, depend on Nette\McpInspector\ContainerAccessor in its constructor and follow the built-in pattern.

Standalone Usage

CLI Mode

php vendor/bin/mcp-inspector --project=/path/to/project

HTTP Mode

Copy www/mcp-inspector.php to your web root for HTTP-based MCP access.

Manual MCP Configuration

If not using the Nette plugin, add to your project's .mcp.json:

{
    "mcpServers": {
        "nette-inspector": {
            "command": "php",
            "args": [
                "vendor/nette/mcp-inspector/bin/mcp-inspector",
                "--project=/absolute/path/to/project"
            ]
        }
    }
}

--project is recommended over relying on the host's working directory — some MCP clients spawn the server with an unpredictable cwd.

Security

• All tools are read-only — no data modification
• Database tool only allows SELECT/SHOW/DESCRIBE queries
• Sensitive configuration values are automatically masked
• Development only — do not expose in production

Requirements

• PHP 8.2+
• Nette Framework 3.2+