conformance: create everything-client with basic scenarios and configure GitHub action to run it

- implement all non-auth scenarios (client OAuth is not yet supported)
- sse-retry is also implemented, but failing due to a bug in the SDK
- configure client-conformance job in the conformance GitHub action
- create a client-conformance.sh script and rename conformance.sh to server-conformance.sh

.github/workflows/conformance.yml

@@ -36,3 +36,20 @@ jobs:
           url: http://localhost:3001/mcp
           suite: active
           expected-failures: ./conformance/baseline.yml
+
+  client-conformance:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+      - name: Set up Go
+        uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5
+        with:
+          go-version: "^1.25"
+      - name: "Run conformance tests" 
+        uses: modelcontextprotocol/conformance@c2f3fdaf781dcd5a862cb0d2f6454c1c210bf0f0 # v0.1.11
+        with:
+          mode: client 
+          command: go run ./conformance/everything-client/main.go
+          suite: core
+          expected-failures: ./conformance/baseline.yml

.github/workflows/nightly.yml

@@ -32,5 +32,5 @@ jobs:
       uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4.1.0
       with:
         node-version: "20"
-    - name: Run conformance tests
+    - name: Run server conformance tests
-      run: ./scripts/conformance.sh
+      run: ./scripts/server-conformance.sh

conformance/baseline.yml

@@ -1,4 +1,21 @@
 server:
   # All tests should pass.
 client:
-  # Tests are expected to fail. List will be populated after running the tests.
+- auth/basic-cimd
+- auth/metadata-default
+- auth/metadata-var1
+- auth/metadata-var2
+- auth/metadata-var3
+- auth/2025-03-26-oauth-metadata-backcompat
+- auth/2025-03-26-oauth-endpoint-fallback
+- auth/scope-from-www-authenticate
+- auth/scope-from-scopes-supported
+- auth/scope-omitted-when-undefined
+- auth/scope-step-up
+- auth/scope-retry-limit
+- auth/token-endpoint-auth-basic
+- auth/token-endpoint-auth-post
+- auth/token-endpoint-auth-none  
+- auth/client-credentials-jwt
+- auth/client-credentials-basic
+- sse-retry

conformance/everything-client/main.go

@@ -0,0 +1,248 @@
+// Copyright 2025 The Go MCP SDK Authors. All rights reserved.
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// The conformance client implements features required for MCP conformance testing.
+// It mirrors the functionality of the TypeScript conformance client at
+// https://github.com/modelcontextprotocol/typescript-sdk/blob/main/src/conformance/everything-client.ts
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"slices"
+	"sort"
+	"strings"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+)
+
+// scenarioHandler is the function signature for all conformance test scenarios.
+// It takes a context and the server URL to connect to.
+type scenarioHandler func(ctx context.Context, serverURL string) error
+
+var (
+	// registry stores all registered scenario handlers.
+	registry = make(map[string]scenarioHandler)
+)
+
+// registerScenario registers a new scenario handler with the given name.
+// This function should be called during init() by scenario implementations.
+func registerScenario(name string, handler scenarioHandler) {
+	if _, exists := registry[name]; exists {
+		log.Fatalf("Scenario %q is already registered", name)
+	}
+	registry[name] = handler
+}
+
+func init() {
+	registerScenario("initialize", runBasicClient)
+	registerScenario("tools_call", runToolsCallClient)
+	registerScenario("elicitation-sep1034-client-defaults", runElicitationDefaultsClient)
+	registerScenario("sse-retry", runSSERetryClient)
+}
+
+// ============================================================================
+// Basic scenarios
+// ============================================================================
+
+func runBasicClient(ctx context.Context, serverURL string) error {
+	session, err := connectToServer(ctx, serverURL)
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	_, err = session.ListTools(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("session.ListTools(): %v", err)
+	}
+
+	return nil
+}
+
+func runToolsCallClient(ctx context.Context, serverURL string) error {
+	session, err := connectToServer(ctx, serverURL)
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	tools, err := session.ListTools(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("session.ListTools(): %v", err)
+	}
+
+	idx := slices.IndexFunc(tools.Tools, func(t *mcp.Tool) bool {
+		return t.Name == "add_numbers"
+	})
+	if idx == -1 {
+		return fmt.Errorf("tool %q not found", "add_numbers")
+	}
+
+	_, err = session.CallTool(ctx, &mcp.CallToolParams{
+		Name:      "add_numbers",
+		Arguments: map[string]any{"a": 5, "b": 3},
+	})
+	if err != nil {
+		return fmt.Errorf("session.CallTool('add_numbers'): %v", err)
+	}
+
+	return nil
+}
+
+// ============================================================================
+// Elicitation scenarios
+// ============================================================================
+
+func runElicitationDefaultsClient(ctx context.Context, serverURL string) error {
+	elicitationHandler := func(ctx context.Context, req *mcp.ElicitRequest) (*mcp.ElicitResult, error) {
+		return &mcp.ElicitResult{
+			Action:  "accept",
+			Content: map[string]any{},
+		}, nil
+	}
+
+	session, err := connectToServer(ctx, serverURL, withClientOptions(&mcp.ClientOptions{
+		ElicitationHandler: elicitationHandler,
+	}))
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	tools, err := session.ListTools(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("session.ListTools(): %v", err)
+	}
+
+	var testToolName = "test_client_elicitation_defaults"
+	idx := slices.IndexFunc(tools.Tools, func(t *mcp.Tool) bool {
+		return t.Name == testToolName
+	})
+	if idx == -1 {
+		return fmt.Errorf("tool %q not found", testToolName)
+	}
+
+	_, err = session.CallTool(ctx, &mcp.CallToolParams{
+		Name:      testToolName,
+		Arguments: map[string]any{},
+	})
+	if err != nil {
+		return fmt.Errorf("session.CallTool(%q): %v", testToolName, err)
+	}
+
+	return nil
+}
+
+// ============================================================================
+// SSE retry scenario
+// ============================================================================
+
+func runSSERetryClient(ctx context.Context, serverURL string) error {
+	// TODO: this scenario is not passing yet. It requires a fix in the client SSE handling.
+	session, err := connectToServer(ctx, serverURL)
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+	log.Printf("Connected to server %q", serverURL)
+
+	tools, err := session.ListTools(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("session.ListTools(): %v", err)
+	}
+
+	var testToolName = "test_reconnection"
+	idx := slices.IndexFunc(tools.Tools, func(t *mcp.Tool) bool {
+		return t.Name == testToolName
+	})
+	if idx == -1 {
+		return fmt.Errorf("tool %q not found", testToolName)
+	}
+
+	_, err = session.CallTool(ctx, &mcp.CallToolParams{
+		Name:      testToolName,
+		Arguments: map[string]any{},
+	})
+	if err != nil {
+		return fmt.Errorf("session.CallTool(%q): %v", testToolName, err)
+	}
+
+	return nil
+}
+
+// ============================================================================
+// Main entry point
+// ============================================================================
+
+func main() {
+	if len(os.Args) != 2 {
+		printUsageAndExit("Usage: %s <server-url>", os.Args[0])
+	}
+
+	serverURL := os.Args[1]
+	scenarioName := os.Getenv("MCP_CONFORMANCE_SCENARIO")
+
+	if scenarioName == "" {
+		printUsageAndExit("MCP_CONFORMANCE_SCENARIO not set")
+	}
+
+	handler, ok := registry[scenarioName]
+	if !ok {
+		printUsageAndExit("Unknown scenario: %q", scenarioName)
+	}
+
+	ctx := context.Background()
+	if err := handler(ctx, serverURL); err != nil {
+		log.Fatalf("Scenario %q failed: %v", scenarioName, err)
+	}
+}
+
+func printUsageAndExit(format string, args ...any) {
+	var scenarios []string
+	for name := range registry {
+		scenarios = append(scenarios, name)
+	}
+	sort.Strings(scenarios)
+
+	msg := fmt.Sprintf(format, args...)
+	log.Fatalf("%s\nAvailable scenarios:\n  - %s", msg, strings.Join(scenarios, "\n  - "))
+}
+
+type connectConfig struct {
+	clientOptions *mcp.ClientOptions
+}
+
+type connectOption func(*connectConfig)
+
+func withClientOptions(opts *mcp.ClientOptions) connectOption {
+	return func(c *connectConfig) {
+		c.clientOptions = opts
+	}
+}
+
+// connectToServer connects to the MCP server and returns a client session.
+// The caller is responsible for closing the session.
+func connectToServer(ctx context.Context, serverURL string, opts ...connectOption) (*mcp.ClientSession, error) {
+	config := &connectConfig{}
+	for _, opt := range opts {
+		opt(config)
+	}
+
+	client := mcp.NewClient(&mcp.Implementation{
+		Name:    "test-client",
+		Version: "1.0.0",
+	}, config.clientOptions)
+
+	transport := &mcp.StreamableClientTransport{Endpoint: serverURL}
+
+	session, err := client.Connect(ctx, transport, nil)
+	if err != nil {
+		return nil, fmt.Errorf("client.Connect(): %v", err)
+	}
+
+	return session, nil
+}

scripts/client-conformance.sh

@@ -0,0 +1,85 @@
+#!/bin/bash
+# Copyright 2025 The Go MCP SDK Authors. All rights reserved.
+# Use of this source code is governed by an MIT-style
+# license that can be found in the LICENSE file.
+
+# Run MCP conformance tests against the Go SDK conformance client.
+
+set -e
+
+RESULT_DIR=""
+WORKDIR=""
+CONFORMANCE_REPO=""
+FINAL_EXIT_CODE=0
+
+usage() {
+    echo "Usage: $0 [options]"
+    echo ""
+    echo "Run MCP conformance tests against the Go SDK conformance client."
+    echo ""
+    echo "Options:"
+    echo "  --result_dir <dir>       Save results to the specified directory"
+    echo "  --conformance_repo <dir> Run conformance tests from a local checkout"
+    echo "                           instead of using the latest npm release"
+    echo "  --help                   Show this help message"
+}
+
+# Parse arguments.
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --result_dir)
+            RESULT_DIR="$2"
+            shift 2
+            ;;
+        --conformance_repo)
+            CONFORMANCE_REPO="$2"
+            shift 2
+            ;;
+        --help)
+            usage
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            usage
+            exit 1
+            ;;
+    esac
+done
+
+# Set up the work directory.
+if [ -n "$RESULT_DIR" ]; then
+    mkdir -p "$RESULT_DIR"
+    WORKDIR="$RESULT_DIR"
+else
+    WORKDIR=$(mktemp -d)
+fi
+
+# Build the conformance server.
+go build -o "$WORKDIR/conformance-client" ./conformance/everything-client
+
+# Run conformance tests from the work directory to avoid writing results to the repo.
+echo "Running conformance tests..."
+if [ -n "$CONFORMANCE_REPO" ]; then
+    # Run from local checkout using npm run start.
+    (cd "$WORKDIR" && \
+        npm --prefix "$CONFORMANCE_REPO" run start -- \
+            client --command "$WORKDIR/conformance-client" \
+            --suite core \
+            ${RESULT_DIR:+--output-dir "$RESULT_DIR"}) || FINAL_EXIT_CODE=$?
+else
+    (cd "$WORKDIR" && \
+        npx @modelcontextprotocol/conformance@latest \
+        client --command "$WORKDIR/conformance-client" \
+        --suite core \
+        ${RESULT_DIR:+--output-dir "$RESULT_DIR"}) || FINAL_EXIT_CODE=$?
+fi
+
+echo ""
+if [ -n "$RESULT_DIR" ]; then
+    echo "See $RESULT_DIR for details."
+else
+    echo "Run with --result_dir to save results."
+fi
+
+exit $FINAL_EXIT_CODE

scripts/server-conformance.sh

@@ -0,0 +1,108 @@
+#!/bin/bash
+# Copyright 2025 The Go MCP SDK Authors. All rights reserved.
+# Use of this source code is governed by an MIT-style
+# license that can be found in the LICENSE file.
+
+# Run MCP conformance tests against the Go SDK conformance server.
+
+set -e
+
+PORT="${PORT:-3000}"
+SERVER_PID=""
+RESULT_DIR=""
+WORKDIR=""
+CONFORMANCE_REPO=""
+FINAL_EXIT_CODE=0
+
+usage() {
+    echo "Usage: $0 [options]"
+    echo ""
+    echo "Run MCP conformance tests against the Go SDK conformance server."
+    echo ""
+    echo "Options:"
+    echo "  --result_dir <dir>       Save results to the specified directory"
+    echo "  --conformance_repo <dir> Run conformance tests from a local checkout"
+    echo "                           instead of using the latest npm release"
+    echo "  --help                   Show this help message"
+}
+
+# Parse arguments.
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --result_dir)
+            RESULT_DIR="$2"
+            shift 2
+            ;;
+        --conformance_repo)
+            CONFORMANCE_REPO="$2"
+            shift 2
+            ;;
+        --help)
+            usage
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            usage
+            exit 1
+            ;;
+    esac
+done
+
+cleanup() {
+    if [ -n "$SERVER_PID" ]; then
+        echo "Stopping server..."
+        kill "$SERVER_PID" 2>/dev/null || true
+        wait "$SERVER_PID" 2>/dev/null || true
+    fi
+}
+trap cleanup EXIT
+
+# Set up the work directory.
+if [ -n "$RESULT_DIR" ]; then
+    mkdir -p "$RESULT_DIR"
+    WORKDIR="$RESULT_DIR"
+else
+    WORKDIR=$(mktemp -d)
+fi
+
+# Build the conformance server.
+go build -o "$WORKDIR/conformance-server" ./conformance/everything-server
+
+# Start the server in the background
+echo "Starting conformance server on port $PORT..."
+"$WORKDIR/conformance-server" -http=":$PORT" &
+SERVER_PID=$!
+
+echo "Server pid is $SERVER_PID"
+
+# Wait for server to be ready
+echo "Waiting for server to be ready..."
+if ! timeout 15 bash -c "until curl -s http://localhost:$PORT > /dev/null 2>&1; do sleep 0.5; done"; then
+    echo "Server failed to start within 15 seconds."
+    exit 1
+fi
+
+# Run conformance tests from the work directory to avoid writing results to the repo.
+echo "Running conformance tests..."
+if [ -n "$CONFORMANCE_REPO" ]; then
+    # Run from local checkout using npm run start.
+    (cd "$WORKDIR" && \
+        npm --prefix "$CONFORMANCE_REPO" run start -- \
+            server --url "http://localhost:$PORT" \
+            ${RESULT_DIR:+--output-dir "$RESULT_DIR"}) || FINAL_EXIT_CODE=$?
+else
+    (cd "$WORKDIR" && \
+        npx @modelcontextprotocol/conformance@latest \
+        server --url "http://localhost:$PORT" \
+        ${RESULT_DIR:+--output-dir "$RESULT_DIR"}) || FINAL_EXIT_CODE=$?
+fi
+
+echo ""
+if [ -n "$RESULT_DIR" ]; then
+    echo "See $RESULT_DIR for details."
+else
+    echo "Run with --result_dir to save results."
+fi
+
+exit $FINAL_EXIT_CODE