Examples

Every example lives in examples/ and runs against the dependencies installed in the repository root. Each server example is a server.php whose bootstrap picks the transport from the SAPI it runs under:

# STDIO transport
php examples/server/discovery-calculator/server.php

# Streamable HTTP transport
php -S 127.0.0.1:8000 examples/server/discovery-userprofile/server.php

# Interactive testing with the MCP Inspector
npx @modelcontextprotocol/inspector php examples/server/discovery-calculator/server.php

Server examples

Example	What it shows	Docs
discovery-calculator	Attribute discovery of tools and a resource; ToolCallException for tool errors	Tools
discovery-userprofile	Resource templates and prompts with completion providers; ResourceLink content	Resource templates, Prompts, Completions
explicit-registration	Manual addTool()/addResource()/addResourceTemplate()/addPrompt() without discovery	Registering elements
combined-registration	Discovery and manual registration combined, and which wins on conflict	Registering elements
cached-discovery	Caching the discovery scan in a PSR-16 cache	Server builder
custom-dependencies	Handlers pulling services from a PSR-11 container	Server builder
complex-tool-schema	Rich input schemas from typed parameters, PHP enums and defaults	Schema generation
schema-showcase	#[Schema] constraint attributes: formats, patterns, ranges	Schema generation
env-variables	Configuring a server through environment variables	Server builder
client-communication	Sampling, roots, progress and log messages from inside a handler	Talking back to the client
client-logging	Structured log notifications through the ClientLogger	Logging
elicitation	Asking the user for input mid-call with ClientGateway::elicit() and typed elicitation schemas, on either protocol era	Asking for input
custom-method-handlers	Replacing the built-in tools/list and tools/call request handlers	Custom message handlers
mcp-apps	The MCP Apps extension: a tool that ships an interactive HTML view	Protocol extensions
stateless-lifecycle	Revision 2026-07-28: cache policy, request state, notification bus	Serving both eras, Caching, Subscriptions
oauth-keycloak	OAuth authorization against a Keycloak instance (own README)	Authorization
oauth-microsoft	OAuth authorization against Microsoft Entra ID (own README)	Authorization

Client examples

Example	What it shows	Docs
stdio_discovery_calculator.php	Connecting over STDIO, listing and calling tools, reading resources	Connecting to a server
http_discovery_calculator.php	The same conversation over the Streamable HTTP transport	Transports
stdio_client_communication.php	Answering server-initiated sampling, log and progress messages	Server-initiated requests
http_client_communication.php	The same handlers over the Streamable HTTP transport	Server-initiated requests
stdio_elicitation.php	Answering elicitation requests from an interactive prompt	Server-initiated requests
stdio_roots.php	Exposing workspace roots and signalling roots/list_changed	Server-initiated requests
stateless_lifecycle_client.php	A client that only connects on revision 2026-07-28, see Modern-era client	Connecting to a server

Client examples run directly:

php examples/client/stdio_discovery_calculator.php

The 2026-07-28 lifecycle

stateless-lifecycle/server.php answers both eras on the same URL. On revision 2026-07-28 every request carries its own protocol version and client capabilities, so a call is a single POST with no handshake before it:

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

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":{}}}}'

The example's header comments document the equivalent handshake-era conversation against the same endpoint. Serving both eras explains how the routing works.

Modern-era client

stateless_lifecycle_client.php drives the server above from PHP. By default, a client probes the server with server/discover and falls back to the initialize handshake when the server doesn't speak 2026-07-28. The example turns that fallback off with setFallbackProtocolVersion(null), so it only connects on 2026-07-28. Then it lists and calls tools without a session:

php -S 127.0.0.1:8000 examples/server/stateless-lifecycle/server.php &
php examples/client/stateless_lifecycle_client.php

See Protocol version for the API it uses.