php-sdk/CHANGELOG.md
Christopher Hertel e0b9c1a26f
[Server] Serve ClientGateway::elicit() under the modern lifecycle (#466)
One handler asks the user something on any revision now. Where the client
can be asked mid-request it still is; where it cannot, the ask becomes the
input_required result that revision carries and the same call returns the
answer once the client re-sends it.

Costs one handler entry per ask, so side effects belong after the last
question. Answers from earlier rounds travel in the requestState, which is
why asking more than once needs Builder::setRequestState().

sample() and listRoots() still raise a LogicException there: that revision
removed them outright.
2026-08-20 01:25:59 +02:00

143 lines
22 KiB
Markdown

# Changelog
All notable changes to `mcp/sdk` will be documented in this file.
0.8.0
-----
* Serve `ClientGateway::elicit()`/`elicitUrl()` under the 2026-07-28 lifecycle, so one handler asks the user something on any revision. Where the client can be asked mid-request it still is; where it cannot, `Mcp\Server\Stateless\ElicitationReplay` turns the ask into the `input_required` result that revision carries and returns from the same call once the client re-sends it with the answer — at the cost of entering the handler once per ask. Both methods take an optional `$key` naming an ask across those rounds, defaulting to its position in the handler. Answers from earlier rounds travel in the `requestState`, so a handler asking more than once needs `Builder::setRequestState()`. `sample()` and `listRoots()` still raise a `LogicException` there: that revision removed them outright.
* Speak the 2026-07-28 lifecycle from the client: `Client` opens with `server/discover` instead of `initialize` on that revision, stamps each request's `_meta` with the protocol version, its own capabilities and client info, and sends the standard `Mcp-Method` / `Mcp-Name` / `Mcp-Param-*` headers an intermediary routes on — the last from the new `Mcp\Client\Stateless\ToolCatalog`, which knows from the tool list which arguments a call must mirror. An `input_required` result is answered automatically by `InputRequestResolver`, which asks the host's elicitation, sampling and roots handlers and retries the same request with `inputResponses` and the `requestState` the server sent. `Mcp\Schema\Wire\McpHeader` holds the header names and the `=?base64?…?=` sentinel both sides share.
* Serve both protocol eras from one endpoint: `StreamableHttpTransport` classifies each request — a `2026-07-28` envelope, an `initialize` handshake, or a session-bound follow-up — through the new `Mcp\Server\Wire\InboundClassifier` and routes it to the dispatcher that owns it, so a single URL answers a modern client and a handshake-era one alike. `Server::builder()->build()` now carries both dispatchers; `Builder::withoutModernEra()` opts out and `Builder::setModernVersions()` narrows what the modern leg answers for. `Mcp\Server\InputRequiredShim` lets a handler written for multi round-trip requests also serve a handshake-era client, by turning each ask into the request/response exchange that era has.
* Carry W3C trace context through a request (SEP-414): `traceparent`, `tracestate` and `baggage` in a request's `_meta` are exposed to handlers as `RequestContext::getTraceContext()` and echoed onto the notifications that request causes, so a span stays joined across the response stream. Values pass through exactly as they arrived, and no OpenTelemetry dependency is added.
* Deliver notifications on a `subscriptions/listen` stream (SEP-2575), which previously acknowledged and then carried nothing for the rest of its life. New `Mcp\Server\Subscription\NotificationBusInterface` with two implementations — `InMemoryNotificationBus` for stdio and persistent runtimes, `Psr16NotificationBus` for PHP-FPM, where the worker holding the stream open and the worker publishing are different processes — set with `Builder::setNotificationBus()`. Registry changes are published automatically through a `PublishingEventDispatcher` that wraps whatever PSR-14 dispatcher was configured. `Builder::setSubscriptionLifetime()` replaces the hard-coded 30-second ceiling, where `0` means "until the client or the runtime ends it".
* Add `Mcp\Server\Wire\CachePolicy`, set with `Builder::setCachePolicy()`, to configure the SEP-2549 caching hints the 2026-07-28 lifecycle stamps on a cacheable result. The conservative `ttlMs: 0, cacheScope: private` stays the default, since `public` lets a shared proxy serve one caller's answer to another and only the operator can make that call. A `ReadResourceResult` may also carry its own `ttlMs`/`cacheScope`, which win over the policy.
* Add typed readers to `Mcp\Server\Stateless\InputContext`: `elicitResult()`, `samplingResult()` and `rootsResult()` deserialize a multi round-trip answer instead of handing back the raw array `response()` returns. A malformed answer reads as absent rather than throwing, so a handler asks again — which is what the spec says a server SHOULD do when the information it needs is still missing.
* Answer a request over a response stream under the 2026-07-28 lifecycle: `StatelessProtocol` runs handlers in a fiber, so `$gateway->progress()` and `$gateway->log()` work there as they do in the handshake era. The stream opens only if the handler actually emits something *and* the client's `Accept` admits `text/event-stream`, and the choice is made after the handler's first suspension, so a request that turns out to need `-32021` or `-32602` is still answered with the status the spec fixes for it.
* Honour `io.modelcontextprotocol/logLevel` (SEP-2575), which replaced the `logging/setLevel` RPC: a request naming no level receives no `notifications/message` at all, one naming a level receives the messages at or above it. Adds `LoggingLevel::severity()` and `LoggingLevel::isAtLeast()`.
* [BC Break] Answer a not-found subject with `-32602` (Invalid params) instead of `-32002`, which the 2026-07-28 revision reserves and forbids emitting (SEP-2164). `resources/read` picks the code from the revision serving the request — `-32602` with the uri in `error.data` from `2026-07-28` on, `-32002` below. `prompts/get` for an unknown prompt, `completion/complete` for an unknown reference and `tools/call` for an unknown tool switch to `-32602` in *every* revision: `-32002` was never the code for those. Adds `ProtocolVersion::usesInvalidParamsForResourceNotFound()`.
* Add the multi round-trip requests pattern for the 2026-07-28 lifecycle (SEP-2322): a `tools/call` or `prompts/get` handler returning `Mcp\Schema\Result\InputRequiredResult` comes back as `resultType: "input_required"` carrying the `inputRequests` it needs answered and an opaque `requestState`; the client retries the same request with `inputResponses`, which the handler reads through `RequestContext::getInputContext()`. `Mcp\Server\Stateless\RequestStateCodec` signs and time-bounds the state — set the key with `Builder::setRequestState()`.
* Validate the standard MCP request headers under the 2026-07-28 lifecycle (SEP-2243): `Mcp\Server\Stateless\StandardHeaderValidator`, set with `Builder::setHeaderValidator()`, checks that `Mcp-Method` and `Mcp-Name` agree with the body they travel with and that a `Mcp-Param-*` mirrors the argument its tool marked `x-mcp-header`, answering `-32020` when they disagree. Intermediaries route on these headers, so a value contradicting the body has to be refused rather than ignored.
* [BC Break] `Mcp\Schema\JsonRpc\Error` accepts `null` as its `$id`, and `getId()` may return it. An error response whose id could not be read now omits the member instead of sending `"id": ""` — which claimed the peer had issued a request with an empty-string id. All the `for*()` factories default to `null`, `fromArray()` accepts a missing or explicitly-null id, and `MessageFactory` decodes both as an id-less error rather than rejecting them.
* Preserve the original request `id` on an invalid-but-parseable message (`-32600`) instead of answering it id-less: `InvalidInputMessageException` now carries the recoverable id via `getRequestId()`/`setRequestId()`, threaded from `MessageFactory` through to the error response.
* [BC Break] Add the extensions framework SEP-2133 defines, which MCP Apps sits on. `ExtensionInterface::getId()` now returns the new `Mcp\Schema\Extension\ExtensionIdentifier` value object instead of a string, which validates the identifier against the `_meta` key naming rules at construction time. `ExtensionInterface` also gains `getMessages()`/`getRequestHandlers()`, so an extension can contribute the message classes its methods decode into — without which its methods cannot be decoded at all — and the handlers serving them; extensions that only announce a capability can extend the new `Mcp\Schema\Extension\AbstractExtension` and skip both. `MessageFactory::make()` takes an `$additional` list of message classes, and `RequestHandlerInterface`'s result template is now covariant.
* [BC Break] Drop the SDK-only name pattern on `ResourceDefinition`/`ResourceTemplate` `$name` — the spec allows any string (its own examples use `main.rs` and `Project Files`). URI/URI-template validation is unchanged.
* Add `ClientGateway::supportsExtension()`, `Client\Builder::enableExtension()`, and `ClientCapabilities::withExtensions()` so clients can negotiate and check protocol extensions (e.g. MCP Apps) the same way servers already do. [BC Break] `ServerExtensionInterface` is replaced by the side-agnostic `Mcp\Schema\Extension\ExtensionInterface`.
* Deprecate Roots, Sampling and Logging per SEP-2577 (protocol revision `2026-07-28`, earliest removal `2027-07-28`). They keep working but using them now triggers a deprecation notice — migrate to tool arguments/resource URIs, a direct LLM provider API, and stderr/OpenTelemetry respectively.
* [BC Break] Gate `structuredContent` on the negotiated protocol revision: a tool result that's a PHP list (or an object serializing to a JSON array) is now only sent as `structuredContent` on protocol revisions `2026-07-28`+; older revisions omit it and keep the JSON-encoded value in `content`.
* Add protocol revision negotiation during `initialize`: the server counter-offers a revision it supports, and the client now fails the handshake instead of continuing on an unagreed revision. Adds `Client::getProtocolVersion()` and the `2026-07-28` revision.
* Add sampling-with-tools support: sampling requests can include tools and tool-choice preferences, messages support tool-use/tool-result content blocks, and clients advertise `sampling.context`/`sampling.tools` via `ClientGateway::supportsSamplingTools()`/`supportsSamplingContext()`. A request that violates the spec's tool-flow rules is now rejected with a proper JSON-RPC error instead of being left unanswered.
* [BC Break] `SamplingMessage::$content` and `CreateSamplingMessageResult::$content` may now be a list of content blocks instead of just one — use the new `getContentBlocks()` to always get a list.
* [BC Break] `CreateSamplingMessageResult` now rejects any role other than `assistant`, and rejects empty content, per spec.
* Close the remaining schema gaps for `2025-06-18`/`2025-11-25` and add the `2026-07-28` surface (SEP-2106): url-mode elicitation (`ClientGateway::elicitUrl()`/`supportsElicitationUrl()`), `Implementation::title`, and `outputSchema`/`structuredContent` accepting any JSON value rather than only objects.
* Add `Mcp\Schema\Content\ResourceLink` — reference a resource by URI/name in tool results and prompt messages without embedding its contents.
* Add client-side Roots support: `RootsCallbackInterface`, `Client::sendRootsListChanged()`, and server-side `ClientGateway::listRoots()`/`supportsRoots()`.
* Add `ClientGateway::supportsSampling()` to check the client's advertised capabilities before sending a sampling request, matching `supportsRoots()`/`supportsElicitation()`.
* Fix empty tool/resource schemas serializing as `[]` instead of `{}` in `inputSchema`/`outputSchema`.
* Fix `PromptResultFormatter` dropping `annotations`, `_meta`, and `mimeType` when a prompt generator returns content as a plain array.
* Add `annotations` support to `ImageContent`, matching `TextContent`/`AudioContent`.
0.7.0
-----
* Add client-side elicitation support: `ElicitationCallbackInterface`, `ElicitationRequestHandler`, and `ElicitationException` let clients respond to server elicitation requests.
* Defer element loading to the first registry read: loaders now run at request time (first `has*`/`get*` call) instead of eagerly at `Builder::build()`, fixing empty registries under persistent runtimes (e.g. FrankenPHP worker mode) where a loader's data source is not ready at build time. Adds `Builder::setLazyLoading()` (default on), a public `Registry::load()`, and an optional `LoaderInterface` constructor argument on `Registry`.
* [BC Break] Element loading is lazy by default: loader failures now surface on the first request rather than at `Builder::build()`, and `initialize` advertises capabilities from the configured sources rather than the loaded registry. Call `Builder::setLazyLoading(false)` to restore eager build-time loading.
* Allow `[$instance, 'methodName']` as an element handler in `Builder::addTool()`, `addResource()`, `addResourceTemplate()`, and `addPrompt()`. Unblocks handlers with constructor dependencies that the container-less `new $className()` fallback cannot build.
* Always emit an `items` schema for array tool parameters: untyped arrays get `items: {}` and nullable typed arrays (e.g. `string[]|null`) keep their element type. Fixes strict clients rejecting tools with "array type must have items" (#151).
* Harden JSON-RPC input parsing: single-message vs batch is now decided from the decoded JSON type (object → single, list array → batch) instead of the raw first byte. Scalars, empty payloads, and non-object batch elements are surfaced as `InvalidInputMessageException` entries instead of triggering warnings or a `TypeError`.
* Add `maxBatchSize` (default `100`) to `MessageFactory` — oversized JSON-RPC batches are rejected before any message is constructed, guarding against amplification.
* Add `maxBodyBytes` (default 4 MiB) to `StreamableHttpTransport` — POST bodies exceeding the cap are rejected with `413`. Unknown-size/chunked bodies are read incrementally and stopped at the cap so they cannot exhaust memory.
* Reject malformed `Mcp-Session-Id` headers with a `400` response: a repeated header or a value that is not a valid UUID is now rejected up front instead of surfacing as an uncaught `Uuid::fromString()` error.
* Extract RFC 9728 metadata serving into `ProtectedResourceMetadataHandler`, a transport-neutral PSR-15 `RequestHandlerInterface` that can be mounted directly as a Symfony/Laravel controller; `ProtectedResourceMetadataMiddleware` now delegates to it (no BC break).
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