## Motivation and Context
The three conformance tasks were named `conformance`, `conformance_list`, and `conformance_server`,
spelling out with underscores the grouping that Rake expresses with namespaces.
They are now `conformance:test`, `conformance:list`, and `conformance:server`.
The bare `conformance` task is kept as an alias for `conformance:test`.
## How Has This Been Tested?
By running `rake -T` to confirm the three tasks are grouped under `conformance:`
with the alias listed beside them, `rake --dry-run default` to confirm that the default task
resolves `conformance:test`, and `rake conformance:list` to exercise a renamed task end to end.
## Breaking Changes
None. These are development-only Rake tasks.
## Motivation and Context
When two PRs are merged to main in quick succession, the Conformance Tests run for
the earlier merge commit is cancelled by the run for the later one.
On push events, `github.ref` is always `refs/heads/main`, so every merge to main shares
the same concurrency group and `cancel-in-progress: true` cancels all but the latest run.
As a result, only the last merged PR gets a conformance result.
This change appends `github.sha` to the concurrency group for push events so that
each merge commit runs independently. For pull_request events the SHA part is empty,
keeping the existing behavior where pushing new commits to a PR cancels its superseded runs.
## How Has This Been Tested?
Validated the workflow YAML syntax locally. The concurrent behavior itself can only be
observed on GitHub Actions, by confirming that both Conformance Tests runs complete
when two pushes land on main within a short interval.
## Breaking Changes
None.
## Motivation and Context
The gemspec already declares `required_ruby_version >= 2.7.0`, but `ServerContext` used
the `...` arguments forwarding syntax in `method_missing`. That syntax was added in Ruby 2.7.3,
so requiring the gem raised a `SyntaxError` on Ruby 2.7.0 through 2.7.2, and the library could not
be loaded at all.
RuboCop did not catch this because its Parser backend runs on Ruby 2.7.8, where the syntax is valid.
CI missed it too because the test matrix tested `2.7`, which resolves to the latest 2.7.x rather than
the declared minimum.
## How Has This Been Tested?
Forward arguments explicitly with `*args, **kwargs, &block` so the method loads on Ruby 2.7.0,
and pin the CI test matrix to 2.7.0 so the suite runs against the declared minimum instead of
the latest 2.7.x.
Running the suite on 2.7.0 also requires a `Hash.ruby2_keywords_hash?` shim in the test helper,
since mocha would otherwise raise a `NoMethodError` on that version.
## Breaking Changes
None.
Closes#418
## Motivation
To assess and track the Ruby SDK's compliance with the MCP
specification, integrate `@modelcontextprotocol/conformance` as the
standard evaluation harness. This makes it possible to measure
conformance objectively, catch regressions early, and produce the kind
of evaluation data needed for SDK tier assessments.
## Scope
Only server conformance is included at this point. Client conformance
requires protocol-level features that MCP::Client does not yet
support (initialize handshake, notifications, ping, etc.).
## Usage
Run conformance tests:
```console
bundle exec rake conformance
```
Start the conformance server in the foreground for iterating on a single
scenario without the per-run startup overhead:
```console
bundle exec rake conformance_server
```
## Default Rake Task (`bundle exec rake`)
It is configured to run in order of lower execution cost: `rubocop`, `test`, and then `conformance`.
## CI
`.github/workflows/conformance.yml` file has been added to run the conformance tests in CI.
## SDK Tier Report
The MCP SDK Tier system (https://modelcontextprotocol.io/community/sdk-tiers)
requires SDK maintainers to self-assess and report results to the SDK Working
Group via https://github.com/modelcontextprotocol/modelcontextprotocol/issues.
To generate a full tier assessment report, use the `/mcp-sdk-tier-audit`
slash command from the https://github.com/modelcontextprotocol/conformance repository with
the conformance server running:
```console
# Terminal 1 (this repository): start the conformance server
bundle exec rake conformance_server
# Terminal 2 (conformance repository): run the tier audit skill as a slash command in Claude Code
/mcp-sdk-tier-audit /path/to/modelcontextprotocol/ruby-sdk http://localhost:9292/mcp
```
The skill evaluates conformance pass rate, issue label taxonomy, triage
metrics, documentation coverage, and policy compliance, then produces a
markdown report suitable for tier advancement submissions.
## Summary
Unlike applications, libraries provide value by remaining usable for a broad range of users,
even when that means supporting older Ruby versions beyond Ruby's own EOL timeline.
I maintain RuboCop, a Ruby linter. Because linters need to work across the ecosystem,
they often need to keep compatibility with older Ruby versions to some extent.
The trade-off is that the MCP Ruby SDK must remain compatible with Ruby 2.7.
However, given the ecosystem impact, supporting Ruby 2.7 is still worthwhile.
For example, bundled gems such as `csv` (Ruby >= 2.5), `bigdecimal` (Ruby >= 2.5), `json` (Ruby >= 2.7),
and `language_server-protocol` (Ruby >= 2.5) tend to keep compatibility with older Ruby versions.
Unlike dropping support, which imposes restrictions on users,
this change broadens compatibility and does not introduce breaking changes.
## Development Note
`rubocop-shopify` (2.18) supports Ruby 3.1+, and this PR does not change that.
Since RuboCop can configure the runtime Ruby version and the target Ruby version for analysis independently,
CI continues to run RuboCop on Ruby 4.0, while analyzing code with `TargetRubyVersion: 2.7`.
When setting `TargetRubyVersion: 2.7`, several RuboCop offenses were resolved.
Additionally, Sorbet-related libraries support Ruby 3.0+. Since these are not dependencies of the MCP Ruby SDK itself,
they are versioned and tested in the development Gemfile.
Ruby 4.0.0 has been released, so this PR adds Ruby 4.0 to CI.
https://www.ruby-lang.org/en/news/2025/12/25/ruby-4-0-0-released/
To prevent the CI label from showing "CI / Test Ruby 4" instead of
"CI / Test Ruby 4.0", the matrix entries are changed from floats to strings.
This adds automated deployment of a versioned API documentation landing
page using GitHub Pages. The landing page links to documentation hosted
on RubyDoc.info, the de facto standard documentation site for the Ruby
ecosystem. The landing page will update to reflect new releases.
Changes
-------
1. **Documentation generation script** (see `bin/generate-gh-pages.sh`)
Copies and commits documentation files to the gh-pages branch. The
script uses git worktrees to isolate the process from the main
workspace.
The script:
- Creates the gh-pages branch as an orphan branch if it doesn't exist
- Parses semantic versions from tag names, ignoring arbitrary
prefixes (e.g., tags `1.2.3`, `v1.2.3`, and `release-1.2.3` all
create `v1.2.3`)
- Determines the latest version using semantic version sorting
- Copies static Jekyll template files from `docs/` to the gh-pages
root (for the latest version only)
- Generates `docs/_data/versions.yml` with a list of all versions
for the Jekyll templates to consume
2. **Jekyll template files** (see `docs/` directory)
- `docs/_config.yml` - Jekyll configuration
- `docs/index.md` - Landing page template that links to all versions
on RubyDoc.info based on generated `docs/_data/versions.yml`
- `docs/latest/index.html` - Redirect page template that redirects
to the latest documentation on RubyDoc.info
3. **GitHub Actions workflow** (see `.github/workflows/release.yml`)
Added a `publish_gh_pages` job that runs after the `publish_gem` job
on release events. The job invokes the generation script with the
release tag name, then pushes the updated gh-pages branch to deploy
the documentation.
4. **CI validation** (see `.github/workflows/ci.yml`)
Added a `yard` job that runs YARD validation with `--no-output`.
This ensures YARD can successfully parse the codebase (without
generating output), catching documentation issues early in CI.
5. **YARD dependencies** (see `Gemfile`)
Added `yard` and `yard-sorbet` gems as development dependencies to
support documentation validation in CI.
YARD documentation is automatically generated and hosted by
RubyDoc.info when the gem is published to RubyGems.org.
6. **Documentation links** (see `README.md` and `mcp.gemspec`)
Added links to the published API documentation on RubyDoc.info in
the README and gemspec metadata.
Documentation URL
-----------------
Custom documentation will be available at:
https://modelcontextprotocol.github.io/ruby-sdk/
RubyDoc.info documentation will be accessible at:
- https://rubydoc.info/gems/mcp (latest version)
- https://rubydoc.info/gems/mcp/1.2.3 (specific versions)
Co-Authored-By: Claude <noreply@anthropic.com>
When running `bundle exec rake` in the local environment, RuboCop is executed,
but it was not included in the CI workflow.
This PR enables RuboCop execution in the CI workflow. RuboCop performs static analysis
on the source code using Ruby 3.2, in accordance with the gemspec setting `spec.required_ruby_version = ">= 3.2.0"`:
6b49222edb/model_context_protocol.gemspec (L16)
In other words, it is not necessary to run RuboCop under every Ruby version from 3.2 to head,
so it is defined as a separate job from the test job.
