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feat: Auto-detect transport type from config files #661

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a0aebdd
feat: Auto-detect transport type from config files
felixweinberger Jul 30, 2025
50b96a0
test: Add minimal test coverage for CLI transport options
felixweinberger Jul 30, 2025
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141 changes: 135 additions & 6 deletions cli/scripts/cli-tests.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -120,6 +120,85 @@ try {
const invalidConfigPath = path.join(TEMP_DIR, "invalid-config.json");
fs.writeFileSync(invalidConfigPath, '{\n "mcpServers": {\n "invalid": {');

// Create config files with different transport types for testing
const sseConfigPath = path.join(TEMP_DIR, "sse-config.json");
fs.writeFileSync(
sseConfigPath,
JSON.stringify(
{
mcpServers: {
"test-sse": {
type: "sse",
url: "http://localhost:3000/sse",
note: "Test SSE server",
},
},
},
null,
2,
),
);

const httpConfigPath = path.join(TEMP_DIR, "http-config.json");
fs.writeFileSync(
httpConfigPath,
JSON.stringify(
{
mcpServers: {
"test-http": {
type: "streamable-http",
url: "http://localhost:3000/mcp",
note: "Test HTTP server",
},
},
},
null,
2,
),
);

const stdioConfigPath = path.join(TEMP_DIR, "stdio-config.json");
fs.writeFileSync(
stdioConfigPath,
JSON.stringify(
{
mcpServers: {
"test-stdio": {
type: "stdio",
command: "npx",
args: ["@modelcontextprotocol/server-everything"],
env: {
TEST_ENV: "test-value",
},
},
},
},
null,
2,
),
);

// Config without type field (backward compatibility)
const legacyConfigPath = path.join(TEMP_DIR, "legacy-config.json");
fs.writeFileSync(
legacyConfigPath,
JSON.stringify(
{
mcpServers: {
"test-legacy": {
command: "npx",
args: ["@modelcontextprotocol/server-everything"],
env: {
LEGACY_ENV: "legacy-value",
},
},
},
},
null,
2,
),
);

// Function to run a basic test
async function runBasicTest(testName, ...args) {
const outputFile = path.join(
Expand Down Expand Up @@ -649,6 +728,56 @@ async function runTests() {
"debug",
);

console.log(
`\n${colors.YELLOW}=== Running Config Transport Type Tests ===${colors.NC}`,
);

// Test 25: Config with stdio transport type
await runBasicTest(
"config_stdio_type",
"--config",
stdioConfigPath,
"--server",
"test-stdio",
"--cli",
"--method",
"tools/list",
);

// Test 26: Config with SSE transport type (should pass transport to client)
await runBasicTest(
"config_sse_type",
"--config",
sseConfigPath,
"--server",
"test-sse",
"echo",
"test",
);

// Test 27: Config with streamable-http transport type
await runBasicTest(
"config_http_type",
"--config",
httpConfigPath,
"--server",
"test-http",
"echo",
"test",
);

// Test 28: Legacy config without type field (backward compatibility)
await runBasicTest(
"config_legacy_no_type",
"--config",
legacyConfigPath,
"--server",
"test-legacy",
"--cli",
"--method",
"tools/list",
);

console.log(
`\n${colors.YELLOW}=== Running HTTP Transport Tests ===${colors.NC}`,
);
Expand All @@ -668,7 +797,7 @@ async function runTests() {

await new Promise((resolve) => setTimeout(resolve, 3000));

// Test 25: HTTP transport inferred from URL ending with /mcp
// Test 29: HTTP transport inferred from URL ending with /mcp
await runBasicTest(
"http_transport_inferred",
"http://127.0.0.1:3001/mcp",
Expand All @@ -677,7 +806,7 @@ async function runTests() {
"tools/list",
);

// Test 26: HTTP transport with explicit --transport http flag
// Test 30: HTTP transport with explicit --transport http flag
await runBasicTest(
"http_transport_with_explicit_flag",
"http://127.0.0.1:3001/mcp",
Expand All @@ -688,7 +817,7 @@ async function runTests() {
"tools/list",
);

// Test 27: HTTP transport with suffix and --transport http flag
// Test 31: HTTP transport with suffix and --transport http flag
await runBasicTest(
"http_transport_with_explicit_flag_and_suffix",
"http://127.0.0.1:3001/mcp",
Expand All @@ -699,7 +828,7 @@ async function runTests() {
"tools/list",
);

// Test 28: SSE transport given to HTTP server (should fail)
// Test 32: SSE transport given to HTTP server (should fail)
await runErrorTest(
"sse_transport_given_to_http_server",
"http://127.0.0.1:3001",
Expand All @@ -710,7 +839,7 @@ async function runTests() {
"tools/list",
);

// Test 29: HTTP transport without URL (should fail)
// Test 33: HTTP transport without URL (should fail)
await runErrorTest(
"http_transport_without_url",
"--transport",
Expand All @@ -720,7 +849,7 @@ async function runTests() {
"tools/list",
);

// Test 30: SSE transport without URL (should fail)
// Test 34: SSE transport without URL (should fail)
await runErrorTest(
"sse_transport_without_url",
"--transport",
Expand Down
62 changes: 51 additions & 11 deletions cli/src/cli.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,8 @@ type Args = {
args: string[];
envArgs: Record<string, string>;
cli: boolean;
transport?: "stdio" | "sse" | "streamable-http";
serverUrl?: string;
};

type CliOptions = {
Expand All @@ -23,11 +25,18 @@ type CliOptions = {
cli?: boolean;
};

type ServerConfig = {
command: string;
args?: string[];
env?: Record<string, string>;
};
type ServerConfig =
| {
type: "stdio";
command: string;
args?: string[];
env?: Record<string, string>;
}
| {
type: "sse" | "streamable-http";
url: string;
note?: string;
};

function handleError(error: unknown): never {
let message: string;
Expand Down Expand Up @@ -74,6 +83,16 @@ async function runWebClient(args: Args): Promise<void> {
startArgs.push("-e", `${key}=${value}`);
}

// Pass transport type if specified
if (args.transport) {
startArgs.push("--transport", args.transport);
}

// Pass server URL if specified
if (args.serverUrl) {
startArgs.push("--server-url", args.serverUrl);
}

// Pass command and args (using -- to separate them)
if (args.command) {
startArgs.push("--", args.command, ...args.args);
Expand Down Expand Up @@ -217,12 +236,33 @@ function parseArgs(): Args {
if (options.config && options.server) {
const config = loadConfigFile(options.config, options.server);

return {
command: config.command,
args: [...(config.args || []), ...finalArgs],
envArgs: { ...(config.env || {}), ...(options.e || {}) },
cli: options.cli || false,
};
if (config.type === "stdio") {
return {
command: config.command,
args: [...(config.args || []), ...finalArgs],
envArgs: { ...(config.env || {}), ...(options.e || {}) },
cli: options.cli || false,
transport: "stdio",
};
} else if (config.type === "sse" || config.type === "streamable-http") {
return {
command: "",
args: finalArgs,
envArgs: options.e || {},
cli: options.cli || false,
transport: config.type,
serverUrl: config.url,
};
} else {
// Backwards compatibility: if no type field, assume stdio
return {
command: (config as any).command || "",
args: [...((config as any).args || []), ...finalArgs],
envArgs: { ...((config as any).env || {}), ...(options.e || {}) },
cli: options.cli || false,
transport: "stdio",
};
}
}

// Otherwise use command line arguments
Expand Down
31 changes: 30 additions & 1 deletion client/bin/start.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,14 @@ function delay(ms) {
return new Promise((resolve) => setTimeout(resolve, ms, true));
}

function getClientUrl(port, authDisabled, sessionToken, serverPort) {
function getClientUrl(
port,
authDisabled,
sessionToken,
serverPort,
transport,
serverUrl,
) {
const host = process.env.HOST || "localhost";
const baseUrl = `http://${host}:${port}`;

Expand All @@ -24,6 +31,12 @@ function getClientUrl(port, authDisabled, sessionToken, serverPort) {
if (!authDisabled) {
params.set("MCP_PROXY_AUTH_TOKEN", sessionToken);
}
if (transport) {
params.set("transport", transport);
}
if (serverUrl) {
params.set("serverUrl", serverUrl);
}
return params.size > 0 ? `${baseUrl}/?${params.toString()}` : baseUrl;
}

Expand Down Expand Up @@ -123,6 +136,8 @@ async function startDevClient(clientOptions) {
sessionToken,
abort,
cancelled,
transport,
serverUrl,
} = clientOptions;
const clientCommand = "npx";
const host = process.env.HOST || "localhost";
Expand All @@ -140,6 +155,8 @@ async function startDevClient(clientOptions) {
authDisabled,
sessionToken,
SERVER_PORT,
transport,
serverUrl,
);

// Give vite time to start before opening or logging the URL
Expand Down Expand Up @@ -173,6 +190,8 @@ async function startProdClient(clientOptions) {
sessionToken,
abort,
cancelled,
transport,
serverUrl,
} = clientOptions;
const inspectorClientPath = resolve(
__dirname,
Expand All @@ -187,6 +206,8 @@ async function startProdClient(clientOptions) {
authDisabled,
sessionToken,
SERVER_PORT,
transport,
serverUrl,
);

await spawnPromise("node", [inspectorClientPath], {
Expand All @@ -208,6 +229,8 @@ async function main() {
let command = null;
let parsingFlags = true;
let isDev = false;
let transport = null;
let serverUrl = null;

for (let i = 0; i < args.length; i++) {
const arg = args[i];
Expand All @@ -233,6 +256,10 @@ async function main() {
} else {
envVars[envVar] = "";
}
} else if (parsingFlags && arg === "--transport" && i + 1 < args.length) {
transport = args[++i];
} else if (parsingFlags && arg === "--server-url" && i + 1 < args.length) {
serverUrl = args[++i];
} else if (!command && !isDev) {
command = arg;
} else if (!isDev) {
Expand Down Expand Up @@ -292,6 +319,8 @@ async function main() {
sessionToken,
abort,
cancelled,
transport,
serverUrl,
};

await (isDev
Expand Down