| Filename | Latest commit message | Latest commit date |
|---|---|---|
927ccdd161
## Motivation and Context The `json-schema-2020-12-preservation` client scenario (SEP-1613, SEP-2106; not scored for 2026-07-28, as it was added after the requirements anchor) failed only because the conformance client had no branch for it: an unknown scenario aborts after connecting, so the harness never observed a `tools/list` nor the schema echo it diffs. The client itself already preserves the vocabulary the scenario checks (`$schema`, `$defs` with `$anchor`, `$ref`, `allOf`/`anyOf`, `if`/`then`/`else`, `additionalProperties`): `Client::Tool#input_schema` is the parsed `tools/list` response untouched, with no dereferencing, validation-time rewriting, or keyword stripping, the same fixture-echo approach the TypeScript and Python conformance clients take. The new branch lists the tools and echoes the focal tool's observed `inputSchema` verbatim through `json_schema_echo`, and the expected-failures entry is removed. ## How Has This Been Tested? The scenario passes 9/9 at its default 2025-11-25 wire. On top of the modern-lifecycle client selection (the SEP-2322 driver branch) it also passes 9/9 at `--spec-version 2026-07-28`, where the SEP-2106 keyword checks are failure-gated instead of skipped. `bundle exec rake` is green, with the conformance task passing its baseline check on both legs, and RuboCop reports no offenses. ## Breaking Changes None. The change is confined to the conformance client and its baseline; the shipped gem is untouched. |
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| .. | ||
| client.rb | ||
| client_runner.rb | ||
| expected_failures.yml | ||
| README.md | ||
| server.rb | ||
| server_runner.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
Runs both server and client conformance tests in sequence. Server conformance starts the
conformance server and tests it. Client conformance spawns test servers for each scenario
and invokes conformance/client.rb against them. Scenarios listed in expected_failures.yml
are allowed to fail without affecting the exit code.
Environment variables
| Variable | Description | Default |
|---|---|---|
PORT |
Server port (server conformance only) | 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 server 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@alpha server --url http://localhost:9292/mcp
# Terminal 2: run a single scenario
npx @modelcontextprotocol/conformance@alpha 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)
server_runner.rb # Starts the server, runs npx conformance server, exits with result code
client.rb # Conformance client (invoked by npx conformance client)
client_runner.rb # Runs npx conformance client, exits with result code
expected_failures.yml # Baseline of known-failing scenarios (server and client)
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.