feat!: guard required MCP spec fields against null#928
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chemicL wants to merge 12 commits intojson-compatibilityfrom
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feat!: guard required MCP spec fields against null#928chemicL wants to merge 12 commits intojson-compatibilityfrom
chemicL wants to merge 12 commits intojson-compatibilityfrom
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Records in McpSchema whose fields the MCP spec marks as required were storing them as nullable Java types with no validation. A caller constructing one of these records with null for a required field would silently produce invalid wire JSON because @JsonInclude(NON_ABSENT) omits null values without complaint. Compact canonical constructors with Assert.notNull are added to seven records: - JSONRPCError (code, message), - ProgressNotification (progressToken, progress), - LoggingMessageNotification (level, data), - CreateMessageRequest (messages, maxTokens), - CallToolResult (content), - SamplingMessage (role, content), - ElicitRequest (message, requestedSchema). Test code that constructed these records without required fields was updated to supply valid values; those tests were testing capability-check or error-path logic that fires after construction, so the missing fields were incidental rather than intentional. Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Deprecate no-arg builder() factories and Builder() constructors on CreateMessageRequest, ElicitRequest, and LoggingMessageNotification. Add new builder(required...) factories that validate required fields upfront. Add new builders for ProgressNotification and JSONRPCError. Null checks in private constructors and required-field setters ensure invalid state cannot be introduced at any point in the builder chain. Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Some clients or servers fail to provide required JSON fields so instead of failing we replace them by default values and log with WARN level and allow the application to make progress. Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
…n (#972) The MCP specification evolves continuously; domain types must absorb new fields and subtypes without breaking existing clients or servers. On the 1.x line this is structurally prevented by sealed interfaces, which make it impossible to add a permitted subtype without breaking exhaustive pattern-match switch expressions in caller code. This commit opens the 2.0 release line, where those constraints are lifted and serialization is made self-contained — independent of any global ObjectMapper configuration. Breaking changes for users migrating from 1.x - Sealed interfaces removed from JSONRPCMessage, Request, Result, Notification, ResourceContents, CompleteReference and Content. Exhaustive switch expressions over these types must add a default branch. - Prompt(name, description, null) no longer silently coerces null arguments to an empty list. Use Prompt.withDefaults() to preserve the previous behaviour. - CompleteCompletion.total and .hasMore are now absent from the wire when not set, rather than being emitted as null. - ServerParameters no longer carries Jackson annotations; it is an internal configuration class, not a wire type. What now works that did not before - CompleteReference polymorphic dispatch (PromptReference vs ResourceReference) works through a plain readValue or convertValue call — no hand-rolled map inspection required. - LoggingLevel deserialization is lenient: unknown level strings produce null instead of throwing. - All domain records now tolerate unknown JSON fields, so a client built against an older SDK version will not fail when a newer server sends fields it does not yet recognise. - Null optional fields are consistently absent from serialized output regardless of ObjectMapper configuration. Documentation - CONTRIBUTING adds an "Evolving wire-serialized records" section: a 9-rule recipe and example for adding a field safely. - MIGRATION-2.0 documents all breaking changes listed above. Follow-up coming next Several spec-required fields (e.g. JSONRPCError.code/message, ProgressNotification.progress, CreateMessageRequest.maxTokens, CallToolResult.content) are stored as nullable Java types without a null guard. If constructed with null, the NON_ABSENT rule silently omits them, producing invalid wire JSON without throwing. Fix: compact canonical constructors with Assert.notNull, following the pattern already in JSONRPCRequest. Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
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Compact canonical constructors with Assert.notNull are added to seven records:
This PR is stacked on top of #927
Motivation and Context
Records in McpSchema whose fields the MCP spec marks as required were storing them as nullable Java types with no validation. A caller constructing one of these records with null for a required field would silently produce invalid wire JSON because @JsonInclude(NON_ABSENT) omits null values without complaint.
At the same time, we try to be lenient to not reject existing integrations that fail to comply with the specification and don't provide required fields. In this case we replace missing values with defaults and log the fact.
How Has This Been Tested?
Test code that constructed these records without required fields was updated to supply valid values; those tests were testing capability-check or error-path logic that fires after construction, so the missing fields were incidental rather than intentional.
Breaking Changes
Behavioural - validation failures for required fields that turn out to be null or missing.
Types of changes
Checklist