Missing `@JsonIgnoreProperties(ignoreUnknown = true)` on capability sub-records
還沒有人認領這個 Issue。
評估
研究方向
從 mcp-core/src/main/java/io/modelcontextprotocol/spec/McpSchema.java 開始，檢查列出的 capability record，並將其與 ClientCapabilities 和 ServerCapabilities 進行比較。完成標準是：在反序列化期間，忽略每個受影響的 capability 子記錄中的未知欄位，包括巢狀的 elicitation record。
由索引模型根據 Issue 內容生成。
描述
Bug description
The top-level ClientCapabilities and ServerCapabilities records have @JsonIgnoreProperties(ignoreUnknown = true), but their nested sub-records do not. Since the ObjectMapper is constructed with default settings (FAIL_ON_UNKNOWN_PROPERTIES = true), any unknown field on a capability sub-object causes a deserialization failure.
This already caused a real breakage when the elicitation capability gained form and url fields (#724, fixed in #731), but the systemic issue remains — the next spec addition to any capability sub-object will break older SDK versions again.
Affected records
In McpSchema.java:
| Record | Line | Has annotation? |
|---|---|---|
ClientCapabilities |
383 | Yes |
RootCapabilities |
397 | Yes |
Sampling |
410 | No |
Elicitation |
437 | No |
Elicitation.Form |
443 | No |
Elicitation.Url |
450 | No |
ServerCapabilities |
535 | Yes |
CompletionCapabilities |
548 | No |
LoggingCapabilities |
555 | No |
PromptCapabilities |
565 | No |
ResourceCapabilities |
576 | No |
ToolCapabilities |
587 | No |
Spec reference
The spec schema explicitly states capabilities are not a closed set:
"Known capabilities are defined here, in this schema, but this is not a closed set: any client can define its own, additional capabilities."
ClientCapabilities in schema.json — additionalProperties: false is never set on any capability object or sub-object. Several sub-capabilities (sampling, elicitation, completions, logging) explicitly set additionalProperties: true.
Expected behavior
Unknown fields on capability sub-objects should be silently ignored, matching the behavior of the top-level ClientCapabilities and ServerCapabilities records.
Related
- #734 — reports the same issue for
ToolCapabilitiesspecifically - #724 / #731 — the elicitation breakage that was fixed by adding fields, not by adding the annotation
- 主要語言
- Java
- 星號
- 3.7k
- 分支
- 1.1k
- 平均合併
- 1 天 15 小時
- 30 天內合併 PR
- 9
貢獻指南
從這裡開始
- 先讀完整個 Issue，再讀專案的貢獻指南。
- 在 Issue 下留言說明你要接手 —— 這能避免兩個人做同樣的事。
- Fork 儲存庫，在一個分支上完成修改。
- 送出 Pull Request，並在描述裡引用這個 Issue 編號。
modelcontextprotocol/java-sdk 的其他 Issue
-
area/transport bug P2
難度 2/5 1-3 小時 新手友好度 88/100
modelcontextprotocol/java-sdk#1136 ·
-
area/client bug P2
難度 2/5 1-3 小時 新手友好度 84/100
modelcontextprotocol/java-sdk#1124 · 1 則留言 ·
-
ServerCapabilities.logging is added unconditionally, overriding the caller's explicit capabilities 未關閉bug P2 ready for work
難度 2/5 1-3 小時 新手友好度 68/100
modelcontextprotocol/java-sdk#1086 · 1 則留言 ·
-
enhancement good first issue P3
難度 2/5 1-3 小時 新手友好度 82/100
modelcontextprotocol/java-sdk#1067 ·
-
bug P2 ready for work
難度 2/5 1-3 小時 新手友好度 74/100
modelcontextprotocol/java-sdk#898 · 1 則留言 ·
查看 modelcontextprotocol/java-sdk 的全部 Issue
相似的 Issue
-
area-deployment area-integrations triage:bot-seen
難度 2/5 半天 新手友好度 86/100
-
難度 2/5 1-3 小時 新手友好度 75/100
apache/flink-agents#1156 ·
-
area/connectors autoteam community connectors/source/shopify needs-triage team/use type/bug
難度 2/5 1-3 小時 新手友好度 84/100
-
難度 2/5 1-3 小時 新手友好度 70/100
-
難度 1/5 1 小時以內 新手友好度 85/100