| Filename | Latest commit message | Latest commit date |
|---|---|---|
## Motivation and Context The MCP specification defines `resources/subscribe`, `resources/unsubscribe`, and `notifications/resources/updated` for clients to monitor resource changes: https://modelcontextprotocol.io/specification/2025-03-26/server/resources#subscriptions The Ruby SDK had stub (no-op) handlers but provided no way for server developers to customize subscription behavior or send update notifications. Following the Python SDK approach, the SDK does not track subscription state internally. Server developers register handler blocks and manage their own subscription state, allowing flexibility for different subscription semantics (per-session tracking, persistence, debouncing, etc.). Three methods are added: - `Server#resources_subscribe_handler`: registers a handler for `resources/subscribe` requests - `Server#resources_unsubscribe_handler`: registers a handler for `resources/unsubscribe` requests - `ServerSession#notify_resources_updated`: sends a `notifications/resources/updated` notification to the subscribing client `ServerContext#notify_resources_updated` is also added so that tool handlers can send the notification scoped to the originating session. ## How Has This Been Tested? All tests pass (`rake test`), RuboCop is clean. New tests cover custom handler registration for `resources/subscribe` and `resources/unsubscribe`, session-scoped `notify_resources_updated` notifications, error handling, and `ServerContext` delegation. ## Breaking Changes None. |
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| .. | ||
| expected_failures.yml | ||
| README.md | ||
| runner.rb | ||
| server.rb | ||
MCP Conformance Tests
Validates the Ruby SDK's conformance to the MCP specification using @modelcontextprotocol/conformance.
Prerequisites
- Node.js (for
npx) bundle installcompleted
Running the Tests
Run all scenarios
bundle exec rake conformance
Starts the conformance server, runs all active scenarios against it, prints a pass/fail
summary for each scenario, and exits with a non-zero status code if any unexpected failures
are detected. Scenarios listed in expected_failures.yml are allowed to fail without
affecting the exit code.
Environment variables
| Variable | Description | Default |
|---|---|---|
PORT |
Server port | 9292 |
SCENARIO |
Run a single scenario by name | (all) |
SPEC_VERSION |
Filter scenarios by spec version | (all) |
VERBOSE |
Show raw JSON output when set | (off) |
# Run a single scenario
bundle exec rake conformance SCENARIO=ping
# Use a different port with verbose output
bundle exec rake conformance PORT=3000 VERBOSE=1
# Start the server on a specific port
bundle exec rake conformance_server PORT=3000
Start the server and test separately
# Terminal 1: start the server
bundle exec rake conformance_server
# Terminal 2: run all scenarios
npx @modelcontextprotocol/conformance server --url http://localhost:9292/mcp
# Terminal 2: run a single scenario
npx @modelcontextprotocol/conformance server --url http://localhost:9292/mcp --scenario ping
Keeps the server alive between test runs, which avoids the startup overhead when iterating on a single scenario. Stop the server with Ctrl+C when done.
List available scenarios
bundle exec rake conformance_list
Prints all scenario names that can be passed to SCENARIO.
SDK Tier Report
The MCP SDK Tier system requires SDK maintainers to self-assess and report results to the SDK Working Group via modelcontextprotocol/modelcontextprotocol issues.
To generate a full tier assessment report, use the /mcp-sdk-tier-audit slash command from
the modelcontextprotocol/conformance
repository with the conformance server running:
# 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.
File Structure
conformance/
server.rb # Conformance server (Rack + Puma, default port 9292)
runner.rb # Starts the server, runs npx conformance, exits with result code
expected_failures.yml # Baseline of known-failing scenarios
README.md # This file
Known Limitations
Known-failing scenarios are registered in conformance/expected_failures.yml. They are allowed to
fail without affecting the exit code and are tracked to catch regressions.
These are shown in the output of bundle exec rake conformance.