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:

# 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

The examples log what they do. Debug messages only show up when you enable them, see Debugging.

Run with Inspector:

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:

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:

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:

npx @modelcontextprotocol/inspector -e DEBUG=1 -e FILE_LOG=1 php examples/server/discovery-calculator/server.php