Make mode in elicitation backwards compatible #1863
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…lity For backwards compatibility with servers that don't include the mode field in form-based elicitation requests, mode is now optional and defaults to 'form'. This aligns with the spec language stating that an empty elicitation capability object is equivalent to declaring support for form mode only. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Clarify that servers MAY omit the mode field for form mode elicitation requests, and clients MUST treat such requests as form mode. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
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@nbarbettini / @wdawson could you take a look at this? |
felixweinberger
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also @dend as sponsor (i'll need core-maintainer codeowners) |
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@pcarleton @felixweinberger The TS SDK will need to be adjusted. I'll do a quick PR there after this schema change is merged. |
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Summary
Makes the
modefield optional inElicitRequestFormParamsto maintain backwards compatibility with existing servers that don't include themodefield in form-based elicitation requests.Motivation and Context
When URL elicitation was added (SEP-1036), the
modefield became required to distinguish between form and URL elicitation modes. However, this broke backwards compatibility with existing servers that were sending elicitation requests without amodefield.The spec already states:
This change extends that backwards compatibility to the request schema itself - requests without a
modefield should be treated as form mode.How Has This Been Tested?
Tested with the MCP conformance test suite (
tools-call-elicitationscenario). Before this change, the test failed with a schema validation error:After applying this change (and the corresponding TypeScript SDK change to use
z.literal('form').optional()), the test passes.Breaking Changes
None - this is a backwards-compatible change. Servers can continue to either:
modefield (treated as form mode)mode: "form"mode: "url"for URL-based elicitationTypes of changes
Checklist
Additional context
The generated
schema.jsonandschema.mdxfiles have been updated by runningnpm run generate:schema.