ZeroMCP v0.1.0 is here. v0.2.0 coming soon.
PHP

Faster than bare echo.
593 lines.

zeromcp vs mcp/sdk — side by side.

Dependencies
0 ZeroMCP
vs.
22 Official SDK
Throughput
1,561 req/s
vs.
17 req/s
Memory
33 MB
vs.
64 MB

This is a hello world

Use statement, server instantiation, class-based registration, schema array, and transport setup. 9 lines of ceremony before your tool does anything.

mcp/sdk 9 lines
use Mcp\Server\McpServer;

$server = new McpServer('test', '1.0.0');
$server->registerTool('hello',
    'Say hello',
    ['name' => ['type' => 'string']],
    function($args) {
        return "Hello, {$args['name']}!";
    });
$server->runStdio();

This is the whole server

No use statement. No server class. No registration closures.
Drop it in a folder and run zeromcp serve.

ZeroMCP 9 lines
<?php
// tools/hello.php
$TOOL = [
    'description' => 'Say hello',
    'input' => ['name' => 'string']
];

function execute($args, $ctx) {
    return "Hello, {$args['name']}!";
}

HTTP Performance — Head to Head

Same hello tool. Same methodology. 5-minute sustained load in Docker. Slim for ZeroMCP, stdio proxy for the official SDK.

req/s CPU Memory Ratio
ZeroMCP (Slim) 1,561 0.00% 33 MB 92x
Official SDK 17 0.36% 64 MB

The official PHP SDK processes 17 requests per second (54ms each). ZeroMCP on Slim handles 1,561 — 92x faster.

ZeroMCP HTTP Frameworks

ZeroMCP embedded natively in PHP frameworks. No proxy. No subprocess. 30-second sustained load.

req/s p99 CPU load Memory
Slim 1,960 1.43ms 30 MB

What's different

  • SandboxEnforced. Not advisory.
  • CredentialsPer-directory. Not getenv().
  • ProcessesOne. Not N.
  • Hot reloadBuilt-in. Not restart.
  • ComposabilityConnect remote MCP servers. Official SDK can't.
  • TransportStreamable HTTP by default. Stdio too.

When to use the official SDK

ZeroMCP makes trade-offs. Here's what you give up.

Resources and prompts

ZeroMCP implements tools only. If you need MCP resources, prompts, or sampling, use the official SDK.

Class registration

ZeroMCP uses file-based tools. If you prefer OOP class-based registration, use the official SDK.

Spec parity

The official SDK tracks every spec change immediately. ZeroMCP prioritizes stability over spec completeness.

Enterprise support

The official SDK is maintained by the MCP specification team at Anthropic. ZeroMCP is maintained by the antidrift team (Reloop Labs, LLC).

Drop a .php file. It's an MCP tool.