Add API documentation with GitHub Pages deployment

.github/workflows/ci.yml

@@ -31,3 +31,14 @@ jobs:
           ruby-version: 3.2 # Specify the oldest supported Ruby version.
           bundler-cache: true
       - run: bundle exec rake rubocop
+
+  yard:
+    runs-on: ubuntu-latest
+    name: YARD Documentation
+    steps:
+      - uses: actions/checkout@v5
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.2 # Specify the oldest supported Ruby version.
+          bundler-cache: true
+      - run: bundle exec yard --no-output

.github/workflows/release.yml

@@ -23,3 +23,35 @@ jobs:
           bundler-cache: true
           ruby-version: 3.4
       - uses: rubygems/release-gem@v1
+
+  publish_gh_pages:
+    if: github.repository_owner == 'modelcontextprotocol'
+    name: Publish Documentation to GitHub Pages
+    runs-on: ubuntu-latest
+    needs: [publish_gem]
+
+    permissions:
+      contents: write
+
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0 # Fetch all history for all branches and tags
+
+      - name: Configure Git
+        run: |
+          git config --global user.name "github-actions[bot]"
+          git config --global user.email "github-actions[bot]@users.noreply.github.com"
+
+      - name: Get version tag
+        id: version
+        run: |
+          git fetch --tags
+          TAG=$(git describe --tags --exact-match HEAD)
+          echo "tag=${TAG}" >> $GITHUB_OUTPUT
+
+      - name: Generate GitHub Pages
+        run: ./bin/generate-gh-pages.sh ${{ steps.version.outputs.tag }}
+
+      - name: Push to gh-pages
+        run: git push origin gh-pages

Gemfile

@@ -17,6 +17,8 @@ gem "activesupport"
 gem "debug"
 gem "rake", "~> 13.0"
 gem "sorbet-static-and-runtime"
+gem "yard", "~> 0.9"
+gem "yard-sorbet", "~> 0.9"
 
 group :test do
   gem "faraday", ">= 2.0"

README.md

@@ -932,3 +932,8 @@ The client provides a wrapper class for tools returned by the server:
 - `MCP::Client::Tool` - Represents a single tool with its metadata
 
 This class provides easy access to tool properties like name, description, input schema, and output schema.
+
+## Documentation
+
+- [SDK API documentation](https://rubydoc.info/gems/mcp)
+- [Model Context Protocol documentation](https://modelcontextprotocol.io)

bin/generate-gh-pages.sh

@@ -0,0 +1,119 @@
+#!/bin/bash
+set -e
+
+# Generates versioned documentation links and commits to gh-pages branch
+#
+# PURPOSE:
+#   This script generates a landing page with links to API documentation on
+#   RubyDoc.info for a specific version tag. This script is invoked by the
+#   publish-gh-pages job in the GitHub Actions workflow
+#   (.github/workflows/release.yml) when a release is published.
+#
+# HOW IT WORKS:
+#   - Creates isolated git worktrees for the specified tag and gh-pages branch
+#   - Copies static Jekyll template files from docs/
+#   - Generates _data/versions.yml with list of versions
+#   - Commits changes to gh-pages (does not push automatically)
+#
+# WORKFLOW:
+#   1. Run this script with a tag name: `generate-gh-pages.sh v1.2.3`
+#   2. Script generates docs and commits to local gh-pages branch
+#   3. Push gh-pages branch to deploy: `git push origin gh-pages`
+
+# Parse semantic version from tag name (ignoring arbitrary prefixes)
+if [[ "${1}" =~ ([0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z0-9.-]+)?)$ ]]; then
+  VERSION="v${BASH_REMATCH[1]}"
+else
+  echo "Error: Must specify a tag name that contains a valid semantic version"
+  echo "Usage: ${0} <tag-name>"
+  echo "Examples:"
+  echo "  ${0} 1.2.3"
+  echo "  ${0} v2.0.0-rc.1"
+  exit 1
+fi
+
+TAG_NAME="${1}"
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+
+echo "Generating documentation for tag: ${TAG_NAME}"
+
+# Create temporary directories for both worktrees
+WORKTREE_DIR=$(mktemp -d)
+GHPAGES_WORKTREE_DIR=$(mktemp -d)
+
+# Set up trap to clean up both worktrees on exit
+trap 'git worktree remove --force "${WORKTREE_DIR}" 2>/dev/null || true; \
+      git worktree remove --force "${GHPAGES_WORKTREE_DIR}" 2>/dev/null || true' EXIT
+
+echo "Creating worktree for ${TAG_NAME}..."
+git worktree add --quiet "${WORKTREE_DIR}" "${TAG_NAME}"
+
+# Check if gh-pages branch exists
+if git show-ref --verify --quiet refs/heads/gh-pages; then
+  echo "Creating worktree for existing gh-pages branch..."
+  git worktree add --quiet "${GHPAGES_WORKTREE_DIR}" gh-pages
+elif git ls-remote --exit-code --heads origin gh-pages > /dev/null 2>&1; then
+  echo "Creating worktree for gh-pages branch from remote..."
+  git worktree add --quiet "${GHPAGES_WORKTREE_DIR}" -b gh-pages origin/gh-pages
+else
+  echo "Creating worktree for new orphan gh-pages branch..."
+  git worktree add --quiet --detach "${GHPAGES_WORKTREE_DIR}"
+  git -C "${GHPAGES_WORKTREE_DIR}" checkout --orphan gh-pages
+  git -C "${GHPAGES_WORKTREE_DIR}" rm -rf . > /dev/null 2>&1 || true
+fi
+
+# Change to gh-pages worktree
+cd "${GHPAGES_WORKTREE_DIR}"
+
+# Determine if this tag is the latest version
+echo "Determining if ${VERSION} is the latest version..."
+
+# Get all existing version tags from the repository (reverse sorted, newest first)
+ALL_VERSIONS=$(
+  git -C "${REPO_ROOT}" tag --list | \
+  sed -nE 's/^[^0-9]*([0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z0-9.-]+)?)$/v\1/p' | \
+  sort -Vr
+)
+
+# Get the latest version from all version tags
+LATEST_VERSION=$(echo "${ALL_VERSIONS}" | head -n 1)
+
+if [ "${VERSION}" = "${LATEST_VERSION}" ]; then
+  echo "${VERSION} is the latest version"
+else
+  echo "${VERSION} is not the latest version (latest is ${LATEST_VERSION})"
+fi
+
+# Update custom documentation for latest version
+if [ "${VERSION}" = "${LATEST_VERSION}" ]; then
+  echo "Updating custom documentation..."
+
+  # Clean up old custom docs from gh-pages root
+  echo "Cleaning gh-pages root..."
+  git ls-tree --name-only HEAD | xargs -r git rm -rf
+
+  # Copy custom docs from docs/ directory
+  echo "Copying custom docs from ${WORKTREE_DIR}/docs/..."
+  cp -r "${WORKTREE_DIR}/docs/." "${GHPAGES_WORKTREE_DIR}/"
+fi
+
+# Generate version data for Jekyll
+echo "Generating _data/versions.yml..."
+mkdir -p _data
+echo "${ALL_VERSIONS}" | sed 's/^v/- /' > _data/versions.yml
+
+# Stage all changes
+git add .
+
+# Commit if there are changes
+if git diff --staged --quiet; then
+  echo "No changes to commit"
+else
+  echo "Committing documentation for ${VERSION}..."
+  git commit -m "Add ${VERSION} docs"
+
+  echo "Documentation committed to gh-pages branch!"
+  echo "Push to remote to deploy to GitHub Pages"
+fi
+
+echo "Done!"

docs/_config.yml

@@ -0,0 +1,6 @@
+# Use package name as site title
+title: "MCP Ruby SDK"
+
+# Include generated files and directories which may start with underscores
+include:
+  - "_*"

docs/index.md

@@ -0,0 +1,7 @@
+---
+# Empty Jekyll front matter to enable Liquid templating (see {{ ... }} below)
+---
+
+{% for version in site.data.versions -%}
+- [v{{ version }}](https://rubydoc.info/gems/mcp/{{ version }})
+{% endfor %}

docs/latest/index.html

@@ -0,0 +1,19 @@
+---
+# Empty Jekyll front matter to enable Liquid templating (see {{ ... }} below)
+---
+
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Redirecting to latest documentation...</title>
+  <meta http-equiv="refresh" content="0; url=https://rubydoc.info/gems/mcp">
+  <link rel="canonical" href="https://rubydoc.info/gems/mcp">
+</head>
+<body>
+  <p>Redirecting to <a href="https://rubydoc.info/gems/mcp">latest documentation</a>...</p>
+  <script>
+    window.location.href = "https://rubydoc.info/gems/mcp";
+  </script>
+</body>
+</html>

mcp.gemspec

@@ -20,6 +20,7 @@ Gem::Specification.new do |spec|
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
   spec.metadata["bug_tracker_uri"] = "#{spec.homepage}/issues"
+  spec.metadata["documentation_uri"] = "https://rubydoc.info/gems/mcp"
 
   spec.files = Dir.chdir(File.expand_path("..", __FILE__)) do
     %x(git ls-files -z).split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }