<!-- Provide a brief summary of your changes -->
## Motivation and Context
This PR ensures that the draft URL points to the actual draft schema
improvement suggested in
https://github.com/modelcontextprotocol/registry/issues/814
## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
## Breaking Changes
<!-- Will users need to update their code or configurations? -->
## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed
## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->
The schema in this repo may contain unreleased changes, so labeling it
with a dated version URL is misleading. Change to use a `draft` URL
instead, and add documentation for the schema contribution process.
- Update $id in server.schema.json to use draft URL
- Update example $schema URL in openapi.yaml
- Add Draft (Unreleased) section to CHANGELOG.md
- Add CONTRIBUTING.md with process for making/releasing schema changes
Written by Claude Code, reviewed and tweaked by me.
Co-authored-by: Claude <noreply@anthropic.com>
<!-- Provide a brief summary of your changes -->
## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
Addressing
https://github.com/modelcontextprotocol/registry/pull/634#issuecomment-3410615843
## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
## Breaking Changes
<!-- Will users need to update their code or configurations? -->
## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed
## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->
Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>
This PR adds a Go tool that extracts the ServerDetail schema from
openapi.yaml and generates server.schema.json, ensuring the two specs
stay in sync.
## Key Changes
### New Tooling
- **Go tool** at `tools/extract-server-schema/` that auto-discovers all
schemas referenced by ServerDetail and extracts them from OpenAPI
- **make targets**: `generate-schema` (generates schema) and
`check-schema` (verifies sync)
- `check-schema` is now included in `make validate` and `make check`
### Preserved Validation Constraints
The initial auto-generated schema lost many important validation rules
and descriptive guidance from the hand-crafted version. The OpenAPI spec
has been updated to preserve:
**Security & Descriptions:**
- Command injection security warning on Arguments
- Detailed field descriptions with usage guidance
- `placeholder` field for Input schema
**Validation Constraints:**
- `fileSha256` pattern validation (`^[a-f0-9]{64}$`)
- Package version restrictions (minLength: 1, no "latest")
- `transport` as required field in Package
- ServerDetail `name` pattern and length constraints (3-200 chars)
- Description, title, and version length limits
**Documentation:**
- Repository field descriptions (url, source, id, subfolder)
- PositionalArgument `valueHint` explains transport URL substitution
- Updated examples to match hand-crafted version (Weather API theme)
**Intentional Changes:**
- Removed `additionalProperties` constraints for flexibility
- Updated schema title to be more descriptive
- Added `$comment` noting auto-generation
See the commit "Preserve validation constraints in auto-generated
server.schema.json" for details.
### Fixed Missing Package.transport
- Added `transport` field to OpenAPI Package schema (was in Go model at
`pkg/model/types.go:30` but missing from OpenAPI)
- Split transport types into three separate schemas with proper
discriminated unions:
- `StdioTransport` - Only requires `type: stdio`
- `StreamableHttpTransport` - Requires `type` and `url`, supports
`headers`
- `SseTransport` - Requires `type` and `url`, supports `headers`
- `Package.transport` uses `anyOf` with all three types
- `ServerDetail.remotes` uses `anyOf` with only remote types (no stdio)
### Other Improvements
- Added `GOTOOLCHAIN=auto` to Makefile for Go 1.25 compatibility
- Added `DRIFT_ANALYSIS.md` documenting all schema drift issues found
between specs
## Benefits
**Single Source of Truth**: The OpenAPI spec now serves as the
authoritative schema definition, with server.schema.json automatically
derived from it.
**Better Validation**: All critical validation rules (patterns, length
constraints, required fields) and security warnings are preserved in the
generated schema.
**Improved Developer Experience**:
- Schema changes only need to be made in one place (openapi.yaml)
- CI validation ensures specs never drift apart
- Clear auto-generation comment prevents manual edits
## Validation
✅ All 20 examples validate correctly
✅ Lint passes with 0 issues
✅ Schema is in sync with OpenAPI
✅ All validation constraints from hand-crafted schema preserved
---------
Co-authored-by: Claude <noreply@anthropic.com>
