Conversation
…hema (SEP-1613) MCP embeds JSON Schema documents in three places — Tool.inputSchema, Tool.outputSchema, and ElicitRequest.requestedSchema — and SEP-1613 mandates that these documents conform to JSON Schema 2020-12 by default. Servers now reject malformed schemas at both build time (McpServer.build()) and runtime (McpAsyncServer/McpStatelessAsyncServer.addTool()), returning an IllegalArgumentException that identifies the offending field and references SEP-1613. Elicitation requests whose requestedSchema violates the meta-schema are rejected before being sent to the client. Schemas that explicitly declare a different dialect via $schema are accepted without meta-schema validation, since 2020-12 is the default, not the only permitted dialect. Resolves #700 Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>
|
LGTM! |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
MCP embeds JSON Schema documents in three places — Tool.inputSchema, Tool.outputSchema, and ElicitRequest.requestedSchema — and SEP-1613 mandates that these documents conform to JSON Schema 2020-12 by default.
Motivation and Context
Servers now reject malformed schemas at both build time (McpServer.build()) and runtime (McpAsyncServer/McpStatelessAsyncServer.addTool()), returning an IllegalArgumentException that identifies the offending field and references SEP-1613. Elicitation requests whose requestedSchema violates the meta-schema are rejected before being sent to the client.
Schemas that explicitly declare a different dialect via $schema are accepted without meta-schema validation, since 2020-12 is the default, not the only permitted dialect.
How Has This Been Tested?
New tests were added.
Breaking Changes
This is a behaviour change required by the 2025-11-25 MCP Specification.
Types of changes
Checklist