# MCP SDK Examples

This directory contains various examples of how to use the PHP MCP SDK.

You can run the examples with the dependencies already installed in the root directory of the SDK.
The bootstrapping of the example will choose the used transport based on the SAPI you use.

For running an example, you execute the `server.php` like this:
```bash
# For using the STDIO transport:
php examples/server/discovery-calculator/server.php

# For using the Streamable HTTP transport:
php -S localhost:8000 examples/server/discovery-userprofile/server.php
```

You will see debug outputs to help you understand what is happening.

Run with Inspector:

```bash
npx @modelcontextprotocol/inspector php examples/server/discovery-calculator/server.php
```

## The 2026-07-28 lifecycle

`stateless-lifecycle/server.php` demonstrates protocol revision `2026-07-28`, which removed the
`initialize` handshake and protocol-level sessions. Like every example it answers both eras — the
Inspector's `initialize` still works — but the interesting part is the modern one:

```bash
php -S 127.0.0.1:8000 examples/server/stateless-lifecycle/server.php
```

Every request carries its own protocol version and client capabilities, so a call is a single POST with
no handshake before it:

```bash
curl -sS http://127.0.0.1:8000/ \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: server/discover' \
  -d '{"jsonrpc":"2.0","id":1,"method":"server/discover","params":{"_meta":{
        "io.modelcontextprotocol/protocolVersion":"2026-07-28",
        "io.modelcontextprotocol/clientCapabilities":{}}}}'
```

`tests/Integration/StatelessLifecycleTest.php` drives this example end to end — discovery, a tool call,
the multi round-trip flow, and the response stream carrying progress and log notifications.

## Debugging

You can enable debug output by setting the `DEBUG` environment variable to `1`, and additionally log to a file by
setting the `FILE_LOG` environment variable to `1` as well. A `dev.log` file gets written within the example's
directory.

With the Inspector you can set the environment variables like this:
```bash
npx @modelcontextprotocol/inspector -e DEBUG=1 -e FILE_LOG=1 php examples/server/discovery-calculator/server.php
```