Array tool parameters without an inferable element type generated `{"type":"array"}` with no `items`, which strict MCP clients (VS Code / Copilot) reject. Always emit `items` (`{}` when the element type is unknown) and recover the element type for nullable typed arrays such as `string[]|null`.
Fixes#151
Builder::build() runs all loaders eagerly and snapshots capabilities from
the resulting registry. Both are computed once, when the server is built.
Under a persistent runtime (e.g. FrankenPHP worker mode) the server is
built a single time, so a loader whose data source is not yet ready at
that moment (cold cache, un-warmed metadata) leaves the registry empty for
the whole process — tools/list stays empty while tools/call still works.
Make deferred loading the default behavior of Registry itself: it takes a
loader and runs it on the first read (has*/get*), moving loading to
request time when the application is initialized. The load runs once; the
loaded flag is set only after a successful load, so a transient failure is
retried on the next read. A re-entrancy guard lets loaders that read the
registry during their own run (e.g. discovery's identity check) observe
the partial state instead of recursing. Registrations made before the
first read survive it.
Expose the switch on Builder via setLazyLoading() (default on) so callers
can opt back into eager loading at build time. In lazy mode capabilities
are advertised from the configured sources so the initialize handshake
does not force a load; in eager mode (or for a registry supplied via
setRegistry(), which is always loaded eagerly) they are read from the
loaded registry.
* Allow pre-built instance handlers in element registration
`HandlerResolver::resolve()` rejected `[$instance, 'methodName']` array
handlers even though the `Handler` type alias and the runtime invoker
already support them, so `Server::builder()->addTool(handler: [$obj, 'bar'])`
threw "Invalid array handler format" at build time.
Relax the array-shape guard to accept an object in slot 0 and normalize it
to its class name for reflection (the same idiom getHandlerDescription()
already uses). This unblocks dependency-injected handler objects that the
container-less `new $className()` fallback cannot build.
Fixes#369
* Use 0.6.1 changelog heading and test instance handler end-to-end
This is a bugfix with no new public API or BC break, so the changelog
entry belongs under 0.6.1 rather than a new 0.7.0 section.
Add an end-to-end test that registers a pre-built instance handler with a
constructor dependency the container-less new $className() fallback cannot
satisfy, then drives a real tools/call through CallToolHandler and asserts
the injected instance is the one invoked.
* Address review: reject Closure array handlers, fix abstract-method message
- HandlerResolver: extract the array-handler guard into a readable
$hasValidTarget check that accepts strings and objects but excludes
\Closure, so [$closure, 'method'] falls through to the format error
instead of the misleading "method not found in class Closure".
- Fix the abstract-method rejection message ("must be abstract" ->
"must not be abstract"), a pre-existing typo in the same branch.
- Tighten the CHANGELOG entry wording.
- Cover Closure rejection with a regression test.
* Move instance-handler entry under 0.7.0 changelog heading
Per review: registering pre-built instance handlers is a feature, not a
patch, so it belongs in a minor release heading.
* [Server] feat: allow runtime handlers
Adds Mcp\Server\Handler\RunTimeHandlerInterface so integrators
(e.g. configuration-driven element sources) can register handlers
whose arguments and execution are resolved at runtime rather than
via PHP reflection of a callable.
ReferenceHandler::handle() dispatches instanceof RunTimeHandler
ahead of the callable/array/string branches, calls filterArguments
to narrow the argument map, and forwards execute() a ClientGateway
built from the active session.
The Registry-layer surface (ElementReference and the four
*Reference subclasses, RegistryInterface, Registry::register*,
ArrayLoader's handler-description helper) is widened to accept the
new type. The Builder/ArrayLoader path keeps its narrow callable
union; exposing runtime handlers there requires reworking
HandlerResolver and is left for a follow-up.
* feat(server): add runtime handler metadata API
Extend RunTimeHandlerInterface with four nullable metadata
accessors (getInputSchema, getOutputSchema, getPromptArguments,
getCompletionProviders) so the loader can obtain element
metadata without reflection.
Add RunTimeHandlerTrait providing null defaults for all four
accessors so single-purpose handlers can override only the
methods relevant to their element kind.
* feat(server): expose runtime handlers via Builder
Widen Builder::addTool, addResource, addResourceTemplate, and
addPrompt to accept RunTimeHandlerInterface instances alongside
the existing closure/array/string handler forms.
Branch ArrayLoader::load() on instanceof RunTimeHandlerInterface
in each of the four registration loops so runtime handlers skip
the reflection-based HandlerResolver/HandlerSchema path and pull
metadata from the interface accessors instead. Require explicit
name and description for runtime handlers and raise
ConfigurationException when missing or when a runtime tool has
no input schema source.
Replace direct $data['handler'] use in error log context with
getHandlerDescription() to avoid serializing large runtime
handler object graphs into log records.
Document the runtime handler API in docs/server-builder.md with a
new Runtime Handlers subsection and add a cross-reference from
docs/mcp-elements.md.
* test(server): cover runtime handler Builder path
Add ArrayLoaderRunTimeHandlerTest covering:
- successful tool registration with handler-supplied input schema,
with kwarg input schema (precedence over the handler), and the
same precedence rule for output schema
- ConfigurationException for tools missing name, description, or
any input schema source
- successful resource registration via Builder kwargs and the
matching missing-name failure mode
- successful resource template registration with completion
providers sourced from the handler and the missing-description
failure mode
- successful prompt registration with arguments and completion
providers sourced from the handler, plus the missing-name
failure mode
- a trait-only fixture verifying the four metadata accessors
return null by default
Update existing ReferenceHandlerTest anonymous classes to use
RunTimeHandlerTrait so they satisfy the widened interface.
* refactor(server): split runtime handler interface
Splits RunTimeHandlerInterface into a minimal base contract (only
execute()) plus element-specific subtypes: RunTimeToolHandlerInterface,
RunTimePromptHandlerInterface, and
RunTimeResourceTemplateHandlerInterface. Each subtype declares only
the metadata accessors relevant to its element kind, so a tool
handler no longer has to no-op out prompt or template methods.
Drops the now-redundant RunTimeHandlerTrait and removes
filterArguments; execute() receives the full argument map directly.
Updates ArrayLoader, ReferenceHandler, and Builder type signatures
to use the per-element interfaces, and rewrites the Runtime
Handlers documentation accordingly.
* refactor(server): rename runtime handler interfaces to Runtime casing
Renames RunTimeHandlerInterface and its element-specific subtypes to
Runtime casing, adds a dedicated RuntimeResourceHandlerInterface so
addResource() rejects mismatched runtime handlers at the type level,
and strips _session and _request from arguments forwarded to runtime
handlers. Hardens ArrayLoader to re-throw ConfigurationException
without wrapping, and extracts inline test fixtures into
tests/Fixtures/Runtime/.
* chore: please the linting gods
* test(server): use Uuid::v4 for symfony/uid 5.4 compatibility
Uuid::v7() was added in symfony/uid 6.2 and breaks the Symfony 5.4
matrix job. Match the convention used elsewhere in the suite.
* refactor(server): split ArrayLoader registration
Extract per-element preparation into dedicated private prepare*
methods for tools, resources, templates, and prompts. Factor the
shared required-field assertion and reflected name/description
resolution into helpers.
* refactor(server): non-null runtime handler types
Drop nullable return types on RuntimeToolHandlerInterface::
getInputSchema(), RuntimePromptHandlerInterface::
getPromptArguments()/getCompletionProviders(), and
RuntimeResourceTemplateHandlerInterface::
getCompletionProviders() in favor of plain arrays.
ArrayLoader no longer needs the null-coalescing
fallbacks, and NullSchemaToolHandler plus its
ConfigurationException test become redundant.
* doc: update docs/server-builder.md
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* feat: peer revie feedback
Introduce a new `Builder::add(...)` pattern for a more generic runtime
handler.
* refactor(server): apply PR 294 review feedback
Move per-interface handler dispatch from ReferenceHandler into
ExplicitElementLoader by wrapping each ElementHandlerInterface in a
Closure that satisfies the existing callable contract, revert the
*Reference / Registry handler-type widening PR 294 introduced, throw
Mcp\Exception\InvalidArgumentException (not \TypeError) on mismatched
Builder::add() pairings, and rename two classes for clarity:
* Mcp\Capability\Registry\Loader\ArrayLoader -> ReflectedElementLoader
* Mcp\Schema\Resource -> Mcp\Schema\ResourceDefinition (no alias)
ReferenceHandler::prepareArguments() now injects ClientGateway by type
and binds an `array $arguments` / `array $variables` closure parameter
from the leftover inbound arguments. This addresses Antoine's coupling
concern (ReferenceHandler no longer knows about the four handler
interfaces) and Chris's package-exception preference, and clears the
phpdoc reserved-word collision Antoine flagged on the resource schema
class. Existing tests are re-targeted to exercise the closure path
through ExplicitElementLoader / ReferenceHandler.
* doc: address PR 294 review feedback
Apply Chris's line-level suggestions on docs/server-builder.md
(rewrap to 120 chars, smoothed Drupal mcp module name-drop in the
explicit-element registration section, exception name reads
Mcp\Exception\InvalidArgumentException), rewrap docs/mcp-elements.md
to 120 chars, and add 0.6.0 CHANGELOG entries covering the
Builder::add() entry point, the new handler interfaces, the new
ExplicitElementLoader, plus three BC breaks (Resource ->
ResourceDefinition rename, ArrayLoader -> ReflectedElementLoader
rename, mismatched-pairing exception swap).
* refactor: address self-review feedback
* CHANGELOG: drop spurious [BC Break] entry for the exception
type Builder::add() raises (method is new in this PR).
* docs/server-builder: revert wrap-only edits to pre-existing
main content; keep 120ch wrapping only for new sections.
* ExplicitElementLoader: trim verbose class docblock.
* ReferenceHandler: rename SPLAT_PARAMETER_NAMES constant to
ARGUMENT_BAG_PARAMETERS.
* refactor: rename CallableHandler to Handler
* style: fix phpdoc param alignment
* refactor: inline $reference->handler access
* fix: maintainer review feedback
docs: mention ExplicitElementLoader in comment
docs: move Drupal reference to README list
docs: drop implementation-only changelog entry
docs: revert rewrap noise from mcp-elements.md
* style: fix phpdoc param alignment
---------
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
Co-authored-by: soyuka <soyuka@users.noreply.github.com>
#301 added the `title` field to the `Resource`/`ResourceTemplate` schema
classes and the `McpResource`/`McpResourceTemplate` attributes, but the
manual registration methods on `Builder` were never updated — so manual
registration could not set a resource title, unlike tools and prompts.
Add a `$title` parameter between `$name` and `$description` (matching
`addTool()`/`addPrompt()`) and propagate it through `ArrayLoader` when
constructing the `Resource`/`ResourceTemplate` objects.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Drop the isManual flag from ElementReference and the discovery-state methods
from RegistryInterface. The Registry becomes a flat last-write-wins map;
DiscoveryLoader owns its own owned-set bookkeeping so re-running discovery
only removes elements it itself contributed. Adds ChainLoader for explicit
composition. Manual-over-discovered precedence is preserved via loader
ordering, not a flag on the reference.
* Add optional namePatterns capability to discovery so that the default scan for `*.php` files can be overridden.
* add default to namePatterns docs
* add an error check if we manage to pass in an empty list of patterns
* add unit tests (and a static entry to classmap for composer.json so it autoloads from a non .php file for the test)
* run php-cs-fixer
* change how default namePatterns are set and make sure all the annotations are correct
* Fix bad whitespace
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* switch to a const default instead of nullable with a check in the function to convert null to a default
* make sure we handle empty arrays
* formatting fixes
* Apply suggestion from @chr-hertel
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* Add changelog entry
---------
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* feat(schema): add top-level title to Tool
Mirror PR #278's Prompt change for Tool:
- Add optional ?string $title to Mcp\Schema\Tool between $name
and $inputSchema. fromArray() now reads $data['title'];
jsonSerialize() emits 'title' right after 'name'. The
@phpstan-type ToolData gains title?: string.
- Add ?string $title to the #[McpTool] attribute between $name
and $description.
- Note ToolAnnotations::$title as deprecated-for-display in
favor of Tool::$title per MCP spec 2025-06-18 (PHPDoc only,
field retained for BC).
Phase 1 of plan 01--tool-title-spec-compliance. Later phases
update Discoverer, Builder::addTool(), ArrayLoader, and the
conformance fixture to match the new signature.
* feat(server): thread title through discovery
- Discoverer::processMethod() now propagates McpTool::$title
into every discovered Tool via named arguments.
- Builder::addTool() accepts ?string $title between $name and
$description. [BC Break] positional callers passing the old
$description as 3rd positional argument must switch to named
arguments, matching the precedent set for addPrompt() in
0.5.0.
- tests/Conformance/server.php migrated to named-argument form
for every addTool() call.
Phase 2 of plan 01--tool-title-spec-compliance.
* feat(loader): forward title in ArrayLoader
ArrayLoader now reads 'title' from each tool config entry and
passes it into the Tool constructor, completing the wiring
from Builder::addTool() through array-driven registration.
The $tools @param array-shape typedef gains title: ?string
between name and description.
Phase 3 of plan 01--tool-title-spec-compliance.
* test(schema): cover Tool.title end-to-end
- New tests/Unit/Schema/ToolTest.php: constructor round-trip,
jsonSerialize key-order when title set vs null, fromArray
tolerance.
- New tests/Unit/Capability/Discovery/DiscovererToolTitleTest
plus a TitleFixture class verifying McpTool(title: ...)
propagates through discovery into the registered Tool.
- New tests/Unit/Capability/Registry/Loader/ArrayLoader...
test verifying array-driven title propagation.
- Extend McpToolTest for title named-arg and default-null.
- Extend BuilderTest with addTool(title: 't') propagation.
- Update tests/Unit/.../RegistryTest, CallToolHandlerTest,
ListToolsHandlerTest and examples/.../server.php
new Tool(...) call sites to pass title (named args) so
they match the new constructor signature.
- CHANGELOG 0.6.0 section: feature bullet + [BC Break]
note for addTool() signature, mirroring 0.5.0 Prompt
entries.
- docs/server-builder.md: addTool() row and prose now
list title? between name and description.
Phase 4 of plan 01--tool-title-spec-compliance. All 730
phpunit tests pass; remaining phpstan warnings are
pre-existing and unrelated to Tool.title.
* refactor(schema): make Tool.title non-BC-breaking
Move `title` to the end of the Tool, Builder::addTool, and McpTool
attribute constructors with a default of null. This preserves
positional-argument compatibility and removes the need for
`title: null` boilerplate at call sites. JSON serialization order
(name, title, inputSchema, ...) is unchanged.
Also tighten the new tests: parameterize ToolTest with data
providers, fold the Discoverer title fixture into the existing
DiscoverableToolHandler, and drop the reflection-heavy Builder
test that overlapped with ArrayLoaderToolTitleTest.
* fix: move title after name
---------
Co-authored-by: DDEV User <nobody@example.com>
* style: apply php-cs-fixer to test files
Addresses drift flagged by the default PHP-CS-Fixer config — mostly
adds missing `: void` return types on pre-existing test methods.
No behavioural changes.
* fix: resolve phpstan errors surfaced by qa
- Drop the obsolete `Method ::test*() has no return type specified`
ignore rule — every test method now declares a return type, so
the pattern never matches and phpstan reports it as unmatched.
- Remove `?? []` from two reads of `CallToolRequest::$arguments`;
the property is typed `array` (non-nullable), so the coalesce is
a no-op that phpstan flags.
---------
Co-authored-by: DDEV User <nobody@example.com>
Split formatting logic from Reference classes into dedicated formatter classes:
- ToolResultFormatter: Formats tool execution results into Content items
- PromptResultFormatter: Formats prompt results into PromptMessage items
- ResourceResultFormatter: Formats resource results into ResourceContents items
This refactor:
- Eliminates 122 lines of code duplication between ResourceReference and
ResourceTemplateReference (identical formatting logic)
- Improves code organization by separating formatting concerns from
capability reference management
- Makes formatters independently testable and reusable
- Reduces Reference classes by ~450 lines while maintaining all functionality
Changes:
- Create src/Capability/Formatter/* with three formatter classes
- Update Reference classes to delegate to formatters instead of inline logic
- Add comprehensive test coverage for all formatter classes
- All existing tests pass; no behavioral changes
* Remove `getSummary` method and update descriptions in snapshots and code
* Add changelog entry
---------
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* fix: standardize error handling across handlers with MCP specification compliance
* Update mcp-elements.md
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* docs: clarify error handling behavior for all element types
* docs: remove unnecessary whitespace in mcp-elements.md
* fix: simplify exception signatures to accept simple messages
* refactor: use specific exceptions in examples for better error handling
* feat: throw exceptions from reference provider instead of returning null
---------
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* feat: replace connect/listen flow with run lifecycle
* feat(transport): add phpstan generics for typed transport returns
* refactor: standardize variable naming for MCP server instances in transport handling
* test: remove unnecessary phpstan-ignore annotation in DocBlockTestFixture
