diff --git a/src/index.ts b/src/index.ts
index d35c676..4afddff 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,7 +7,8 @@ import {
   printClientResults,
   runServerConformanceTest,
   printServerResults,
-  printServerSummary
+  printServerSummary,
+  runInteractiveMode
 } from './runner';
 import { listScenarios, listClientScenarios } from './scenarios';
 import { ConformanceCheck } from './types';
@@ -24,8 +25,10 @@ program
 // Client command - tests a client implementation against scenarios
 program
   .command('client')
-  .description('Run conformance tests against a client implementation')
-  .requiredOption('--command <command>', 'Command to run the client')
+  .description(
+    'Run conformance tests against a client implementation or start interactive mode'
+  )
+  .option('--command <command>', 'Command to run the client')
   .requiredOption('--scenario <scenario>', 'Scenario to test')
   .option('--timeout <ms>', 'Timeout in milliseconds', '30000')
   .option('--verbose', 'Show verbose output')
@@ -34,10 +37,20 @@ program
       // Validate options with Zod
       const validated = ClientOptionsSchema.parse(options);
 
+      // If no command provided, run in interactive mode
+      if (!validated.command) {
+        await runInteractiveMode(
+          validated.scenario,
+          validated.verbose ?? false
+        );
+        process.exit(0);
+      }
+
+      // Otherwise run conformance test
       const result = await runConformanceTest(
         validated.command,
         validated.scenario,
-        validated.timeout
+        validated.timeout ?? 30000
       );
 
       const { failed } = printClientResults(
diff --git a/src/runner/client.ts b/src/runner/client.ts
index 8f3ff1a..d7f8105 100644
--- a/src/runner/client.ts
+++ b/src/runner/client.ts
@@ -170,7 +170,10 @@ export function printClientResults(
   return { passed, failed, denominator };
 }
 
-export async function runInteractiveMode(scenarioName: string): Promise<void> {
+export async function runInteractiveMode(
+  scenarioName: string,
+  verbose: boolean = false
+): Promise<void> {
   await ensureResultsDir();
   const resultDir = createResultDir(scenarioName);
   await fs.mkdir(resultDir, { recursive: true });
@@ -193,7 +196,11 @@ export async function runInteractiveMode(scenarioName: string): Promise<void> {
       JSON.stringify(checks, null, 2)
     );
 
-    console.log(`\nChecks:\n${JSON.stringify(checks, null, 2)}`);
+    if (verbose) {
+      console.log(`\nChecks:\n${JSON.stringify(checks, null, 2)}`);
+    } else {
+      console.log(`\nChecks:\n${formatPrettyChecks(checks)}`);
+    }
     console.log(`\nChecks saved to ${resultDir}/checks.json`);
 
     await scenario.stop();
diff --git a/src/schemas.ts b/src/schemas.ts
index 5f22fc6..5e81c8c 100644
--- a/src/schemas.ts
+++ b/src/schemas.ts
@@ -3,7 +3,7 @@ import { getScenario, getClientScenario } from './scenarios';
 
 // Client command options schema
 export const ClientOptionsSchema = z.object({
-  command: z.string().min(1, 'Command cannot be empty'),
+  command: z.string().min(1, 'Command cannot be empty').optional(),
   scenario: z
     .string()
     .min(1, 'Scenario cannot be empty')
@@ -21,7 +21,8 @@ export const ClientOptionsSchema = z.object({
         .number()
         .positive('Timeout must be a positive number')
         .int('Timeout must be an integer')
-    ),
+    )
+    .optional(),
   verbose: z.boolean().optional()
 });
 
@@ -42,3 +43,18 @@ export const ServerOptionsSchema = z.object({
 });
 
 export type ServerOptions = z.infer<typeof ServerOptionsSchema>;
+
+// Interactive command options schema
+export const InteractiveOptionsSchema = z.object({
+  scenario: z
+    .string()
+    .min(1, 'Scenario cannot be empty')
+    .refine(
+      (scenario) => getScenario(scenario) !== undefined,
+      (scenario) => ({
+        message: `Unknown scenario '${scenario}'`
+      })
+    )
+});
+
+export type InteractiveOptions = z.infer<typeof InteractiveOptionsSchema>;