* [Server] Let the client gateway see modern-era capabilities
The six supports*() probes read session state only InitializeHandler wrote,
so every request served statelessly reported no client capabilities at all —
a tool guarding on them took the unsupported branch without a signal.
StatelessProtocol now writes the request's declaration under the same keys.
* [Server] Reject the RPCs 2026-07-28 removed
resources/subscribe and resources/unsubscribe were still dispatched and
answered 200 OK, recording subscriptions the modern era never reads. They
join initialize, ping and logging/setLevel in the era guard; the handlers
stay registered because the handshake era still serves them.
* [Server] Decode a wrapped Mcp-Name before comparing it
The Base64 sentinel was only unwrapped for Mcp-Param-*, so any resource URI
or tool name outside the header-safe ASCII set — which the spec explicitly
tells clients to wrap — was compared encoded and refused with -32020.
* [Server] Require the MCP-Protocol-Version header
It was only checked for contradicting the body, so omitting it entirely
passed — leaving the value intermediaries route on unenforced. Tied to the
header validator's presence, since that is what a header-bearing transport
installs and stdio carries its metadata inline.
* [Server] Read the modern-era request body whole
A single read() takes whatever the stream cares to give — 64 bytes from a
chunked transfer is legal — so an oversized-but-valid POST came back as a
parse error. Shares the legacy transport's incremental read as a trait.
* [Schema][Server] Answer a notification with a status, not a response
A body with no id was dispatched as a request and came back as a JSON-RPC
error carrying "id": "" — an id nobody issued, and on a path a client uses
to tell a modern server from a legacy one. Notifications now get 202 and no
body, and Error omits an id it could not read instead of emptying it.
* [Server] Stop emitting the error codes 2026-07-28 reserved
resources/read answered -32002, which this revision forbids; prompts/get
and completion/complete answered it for an unknown *name*, which it never
meant; tools/call answered -32601, which belongs to an unknown method.
Only the resources/read code is revision-gated — older peers expect -32002
there, and nowhere else. Also routes the -32021 capability exception out of
the prompt and resource handlers, which were swallowing it into -32603.
The revision has no way for a server to put a request on a response stream,
so a handler that needs input from the user says so in its result instead: a
handler returning InputRequiredResult comes back as
resultType: "input_required" with the asks and an opaque requestState, and
the client retries the same request carrying inputResponses.
RequestContext::getInputContext() is what the handler reads them through.
RequestStateCodec signs and time-bounds the state, so a tampered or expired
one is refused rather than trusted - the state travels through the client,
which is not a place to keep something the server later believes.
* [Server][Tests] Serve the modern (SEP-2575) lifecycle
The revision removed the initialize handshake: every request carries its own
_meta - protocol version, client capabilities, client info - and answers
server/discover for what initialize used to return. There is no session to
keep, so there is nothing for the handshake-era dispatcher to do.
Builder::buildStateless() produces StatelessProtocol, and
StatelessHttpTransport serves it over one POST-only endpoint - GET and
DELETE are 405, and no Mcp-Session-Id exists to hand out.
Results go through a per-era wire codec rather than the handlers, so
resultType and the caching hints are stamped for 2026-07-28 and left off the
revisions that do not define them.
Covered by the modern conformance suite (make conformance-draft-server)
against its own baseline; unit coverage arrives with the fixes stacked on
this.
* Apply suggestions from code review
Co-authored-by: Christopher Hertel <mail@christopher-hertel.de>
* Fix critical stateless-lifecycle bugs from review
- Don't leak internal exception messages to clients on uncaught
\Throwable; use a generic message like the handshake-era protocol
and every built-in handler already do.
- Default a missing/invalid request id to null instead of "", and
stop answering notifications and malformed messages as if they
were "method not found" 404s.
- Read the POST body in a loop instead of a single read() call,
which PSR-7 allows to return short.
* [Schema][Server] Close the 2025-11-25 schema gaps and add the 2026-07-28 surface
Ports the type definitions this SDK still misses outside of sampling tool use,
which #409 and #420 already cover. Every addition is optional and defaults to
current behaviour, so a connection negotiated on an older revision is
unaffected.
From 2025-11-25, elicitation gains modes. ElicitationMode splits `form` —
build a form from the requested schema — from `url`, which sends the user out
of band and returns only the accept/decline/cancel outcome. That is why
requestedSchema becomes optional and `url` appears beside it.
ClientCapabilities learns the matching sub-capabilities, where an
`elicitation` naming no mode declares form, the only shape that existed
before. Icon gains `theme` from the same revision, and Implementation gains
the `title` BaseMetadata has carried since 2025-06-18.
From 2026-07-28, schemas loosen where the revision loosens them: SEP-2106
drops the object-only restriction, so Tool::outputSchema may describe any JSON
value and CallToolResult::structuredContent follows.
The same revision defines three error codes (-32020 header mismatch, -32021
missing required client capability, -32022 unsupported protocol version).
ProtocolVersionMiddleware switches to the last of them, so a rejected version
carries the supported set as structured data the client can retry from rather
than only as prose.
* [Schema] Reject what the 2026-07-28 types cannot represent
`Implementation::title` reached the typed constructor unchecked, so malformed
wire data raised a TypeError instead of InvalidArgumentException.
`ToolUseContent::input` accepted a list and serialized it as a JSON array,
where the protocol requires an object. The empty array stays exempt: it is
also an empty map and still emits `{}`.
`ToolChoice` and `ElicitRequest` read their mode with isset(), which is false
for an explicit null, so `{"mode": null}` silently became the default instead
of being rejected. Both use array_key_exists() now, letting the existing type
check refuse null.
* [Client][Server] Advertise the implementation title through both builders
`Implementation::title` could be parsed but never sent: neither
`Client\Builder::setClientInfo()` nor `Server\Builder::setServerInfo()`
accepted one, so every SDK user emitted null.
Both gain a trailing optional `$title`. On the server it sits where the
Implementation constructor already puts it, so existing positional calls keep
their meaning; the client builder forwards it by name, leaving the icons and
websiteUrl slots defaulted.
* [Schema] Serialize every non-null structuredContent
The object-only hydration guard was never that: `!is_array()` admitted
`[1, 2, 3]` and `[]`, which serialize to JSON arrays, while rejecting the
scalars 2026-07-28 permits. The truthiness emission gate was backwards in the
same way — it dropped `[]`, `0`, `false` and `""`, yet emitted lists, strings
and an empty stdClass.
Hydration now accepts any JSON value, and `null` alone means absent, matching
`ToolResultContent` which already carries this field that way. Which values a
given revision permits is a question for version-aware serialization, which
results cannot answer yet.
* [Schema][Server] Make url elicitation reachable
`ElicitRequest::forUrl()` built a request no SDK user could send: the only
public gateway method always constructed form mode from an ElicitationSchema,
and `request()` is private.
`elicitUrl()` joins `elicit()`, and both funnel through one send path that
hydrates the result with the request's own mode. Without that, a url-mode
accept — contentless by design — threw, because ElicitResult requires content
whenever the action is accept. The result carries no discriminator of its own,
so the mode has to come from the request it answers.
`supportsElicitationUrl()` reports whether the client named the mode, reusing
the sub-capability reader the sampling checks already use.
* [Schema] Add CHANGELOG entry for the 2026-07-28 surface
* [Capability][Schema][Server] Carry the widened structuredContent end to end
Review follow-up on the SEP-2106 widening, which stopped at the type.
`ToolReference::extractStructuredContent()` returned `?array`, so a tool
declaring a scalar `outputSchema` had its result dropped and logged as
unsendable. It returns `mixed` now and keeps a scalar — but only from
2026-07-28 on, and only when the tool declared an outputSchema: without one
the value is already carried in `content`, and advertising it twice is not an
improvement.
`CallToolHandler` only warned about list-shaped `structuredContent` on a
self-built `CallToolResult`, so a scalar reached revisions that require an
object unremarked. The check is on the shape now, not on the list case alone.
`ElicitResult` retained a `content` the spec says is absent from url-mode
results, leaving a malformed response indistinguishable from a valid one.
`Tool::jsonSerialize()` emitted the empty root schema as `[]`, which is not a
schema at all. Sub-schemas already had this treatment.
* Address review feedback on resource_link
Three follow-ups from review of the resource_link work:
* PromptResultFormatter: add a regression test proving the optional
fields of a typed resource_link block (title, description, mimeType,
size, annotations, _meta) survive formatting. The delegation to
ResourceLink::fromArray() already landed while rebasing onto the
PromptResultFormatter refactor, but the existing test only supplied
uri/name and so could not catch a reintroduced field drop.
* ResourceLink::fromArray(): validate optional fields consistently, the
way the equivalent ResourceDefinition::fromArray() already does.
description, mimeType and size now raise InvalidArgumentException
instead of surfacing a TypeError (or silently coercing, for size's
(int) cast); annotations goes through Annotations::tryFromArray(),
which carries the is_array() guard that icons already had; icons uses
Icon::listFromArray() so a non-array entry is reported in context.
* ToolReference::extractStructuredContent(): never emit a list as
structuredContent. The Content guard added earlier fixed only one
instance of the real invariant - structuredContent must be a JSON
object, and a PHP list can never be one. Tool::fromArray() already
enforces the matching rule by rejecting an outputSchema whose type is
not "object", so this aligns the runtime path with it. The test
asserting the opposite for an array-typed outputSchema contradicted
the phpstan type and the fromArray() check introduced alongside it in
the same commit, so it is replaced by tests for the two list shapes.
* Apply the structuredContent object rule to object results too
`extractStructuredContent()` guards raw array results against being emitted
as a JSON array, but the object branch handed back whatever `json_decode()`
produced. A `JsonSerializable` returning a list or a scalar slipped straight
through, producing exactly the `structuredContent` the array guard exists to
prevent — and a return value that contradicts the method's own
`array<string, mixed>|null` signature.
Check the decoded value before returning it, and cover the object branch,
which had no tests at all.
* Document structured tool output
`outputSchema` and `structuredContent` were undocumented: the tool return
value docs covered only the `content` side, and the schema generation
section is about tool parameters.
Add a "Structured Output" subsection covering how to declare the schema,
which return values populate `structuredContent`, and why a list has to be
wrapped in a key to get structured output at all.
* Gate structuredContent on the negotiated protocol revision
SEP-2106 (revision 2026-07-28) widens structuredContent to any JSON value;
earlier revisions require an object. Resolve the revision per request and
apply the matching rule, and warn when a declared outputSchema yields none.
* Resolve the protocol revision on RequestContext
Keeps the `_meta`-then-session lookup in one place instead of per handler,
and exposes the negotiated revision to tool handlers.
* Document reading the negotiated revision from RequestContext
* Warn when a self-built CallToolResult carries an invalid structuredContent
Returning a CallToolResult opts out of the extraction rules, so the value is
still sent unchanged — but a JSON array is not valid before SEP-2106.
* 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>
* 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(server): add bidirectional client communication support
* fix(server): use correct session ID string conversion method
* fix: clean up docblocks for request handler methods in Builder
* fix: merge artifacts
* refactor: reorganize server handlers and transport structure
* feat: move the test files to corresponding directories
* fix: linter issues
* fix: correct PHPDoc formatting and streamline handler imports
* refactor: update import statement for ServerBuilder to Builder
2025-09-29 00:58:04 +02:00
Renamed from src/Server/RequestHandler/CallToolHandler.php (Previous history)
