Changelog

All notable changes to mcp/sdk will be documented in this file.

0.6.0

• Add Builder::add(Tool|ResourceDefinition|ResourceTemplate|Prompt $definition, ElementHandlerInterface $handler) for explicit registration of elements whose schema is only known at runtime.
• Add handler interfaces ToolHandlerInterface, ResourceHandlerInterface, ResourceTemplateHandlerInterface, PromptHandlerInterface, and the ElementHandlerInterface marker.
• [BC Break] Renamed Mcp\Schema\Resource to Mcp\Schema\ResourceDefinition. No alias.
• [BC Break] Renamed Mcp\Capability\Registry\Loader\ArrayLoader to Mcp\Capability\Registry\Loader\ReflectedElementLoader.
• [BC Break] Bump default protocol version to 2025-11-25
• Add support for MCP Apps extension in schema and server
• Add extensions to ServerCapabilities and ClientCapabilities and Builder::enableExtension()
• Allow overriding the default name pattern for Discovery
• Add configurable session garbage collection (gcProbability/gcDivisor)
• Add optional title field to ResourceDefinition and ResourceTemplate for MCP spec compliance
• Add ChainLoader to compose multiple LoaderInterface implementations via explicit ordering.
• Add RegistryInterface::unregisterTool(), unregisterResource(), unregisterResourceTemplate(), unregisterPrompt() — idempotent removals.
• Add RegistryInterface::hasTool(), hasResource(), hasResourceTemplate(), hasPrompt() — by-name existence checks.
• DiscoveryLoader now refreshes only its own previously written entries; manual registrations (via Builder::addTool() etc. or runtime $registry->registerTool() calls) survive rediscovery, and a same-name manual registration takes precedence over discovery on collision.
• [BC Break] Removed ElementReference::$isManual public property and the bool $isManual parameter from all *Reference constructors. Origin tracking is no longer carried on the element; manual-over-discovered precedence is encoded by loader execution order.
• [BC Break] RegistryInterface::registerTool(), registerResource(), registerResourceTemplate(), registerPrompt() lost their trailing bool $isManual = false parameter. Callers using positional arguments must drop the flag.
• [BC Break] Removed RegistryInterface::clear(), getDiscoveryState(), setDiscoveryState(). Rediscovery now goes through DiscoveryLoader::load() directly.
• Registry::register*() semantics changed to plain last-write-wins (overwrites silently) and the methods now return the stored *Reference. The previous "discovered registration is ignored when a manual one already exists" precedence rule still applies, but is now enforced by DiscoveryLoader via reference-identity tracking — and still emits a debug log when a discovery is skipped due to a conflicting registration.
• Add optional title parameter to Builder::addResource() and Builder::addResourceTemplate() for MCP spec compliance
• [BC Break] Builder::addResource() signature changed — $title parameter added between $name and $description. Callers using positional arguments must switch to named arguments.
• [BC Break] Builder::addResourceTemplate() signature changed — $title parameter added between $name and $description. Callers using positional arguments must switch to named arguments.
• Add CorsMiddleware, DnsRebindingProtectionMiddleware, and ProtocolVersionMiddleware for StreamableHttpTransport, composed automatically as the default stack via StreamableHttpTransport::defaultMiddleware()
• [BC BREAK] StreamableHttpTransport constructor: $corsHeaders parameter removed; CORS is now configured via CorsMiddleware. The $middleware parameter is nullable — null (or omitted) installs the default stack; [] disables all defaults. Default Access-Control-Allow-Origin is no longer set (was *).
• [BC Break] ResourceDefinition::__construct() signature changed — $title parameter added between $name and $description. Callers using positional arguments must switch to named arguments.
• [BC Break] ResourceTemplate::__construct() signature changed — $title parameter added between $name and $description. Callers using positional arguments must switch to named arguments.
• [BC Break] McpResource and McpResourceTemplate attribute signatures changed — $title parameter added between $name and $description. Callers using positional arguments must switch to named arguments.

0.5.0

• Add built-in authentication middleware for HTTP transport using OAuth
• Add client component for building MCP clients
• Add Builder::setReferenceHandler() to allow custom ReferenceHandlerInterface implementations (e.g. authorization decorators)
• Add elicitation enum schema types per SEP-1330: TitledEnumSchemaDefinition, MultiSelectEnumSchemaDefinition, TitledMultiSelectEnumSchemaDefinition
• [BC break] Make Symfony Finder component optional. Users would need to install symfony/finder now themselves
• Add LenientOidcDiscoveryMetadataPolicy for identity providers that omit code_challenge_methods_supported (e.g. FusionAuth, Microsoft Entra ID)
• Add OAuth 2.0 Dynamic Client Registration middleware (RFC 7591)
• Add optional title field to Prompt and McpPrompt for MCP spec compliance
• [BC Break] Builder::addPrompt() signature changed — $title parameter added between $name and $description. Callers using positional arguments for $description must switch to named arguments.
• Add optional title field to Tool and McpTool for MCP spec compliance
• [BC Break] Tool::__construct() signature changed — $title parameter added between $name and $inputSchema. Callers using positional arguments must switch to named arguments or pass null for $title.
• [BC Break] McpTool attribute signature changed — $title parameter added between $name and $description. Callers using positional arguments for $description must switch to named arguments.
• [BC Break] Builder::addTool() signature changed — $title parameter added between $name and $description. Callers using positional arguments for $description must switch to named arguments.

0.4.0

• Rename Mcp\Server\Session\Psr16StoreSession to Mcp\Server\Session\Psr16SessionStore
• Add missing handlers for resource subscribe/unsubscribe and persist subscriptions via session
• Introduce SessionManager to encapsulate session handling (replaces SessionFactory) and move garbage collection logic from Protocol.

0.3.0

• Add output schema support to MCP tools
• Add validation of the input parameters given to a Tool.
• Rename Mcp\Capability\Registry\ResourceReference::$schema to Mcp\Capability\Registry\ResourceReference::$resource.
• Introduce SchemaGeneratorInterface and DiscovererInterface to allow custom schema generation and discovery implementations.
• Remove DocBlockParser::getSummary() method, use DocBlockParser::getDescription() instead.

0.2.2

• Throw exception when trying to inject parameter with the unsupported names $_session or $_request.
• Throwable objects are passed to log context instead of the exception message.

0.2.1

• Add RunnerControl for StdioTransport to allow break out from continuously listening for new input.
• Open range of supported Symfony versions to include v5.4

0.2.0

• Make Protocol stateless by decouple if from TransportInterface. Removed Protocol::getTransport().
• Change signature of Builder::addLoaders(...$loaders) to Builder::addLoaders(iterable $loaders).
• Removed ClientAwareInterface in favor of injecting a RequestContext with argument injection.
• The ClientGateway cannot be injected with argument injection anymore. Use RequestContext instead.
• Removed ClientAwareTrait
• Removed Protocol::getTransport()
• Added parameter for TransportInterface to Protocol::processInput()

0.1.0

• First tagged release of package
• Support for implementing MCP server