fix(webchat): route slash commands through agent command fast-path

docs/plans/state.json

@@ -1,6 +1,6 @@
 {
   "version": "1.0",
-  "updated_at": "2026-02-18",
+  "updated_at": "2026-02-19",
   "description": "Tracks the status of all Flynn plans and implementation phases",
   "plans": {
     "makefile-skills-convenience-targets": {
@@ -5548,6 +5548,17 @@
         "docs/plans/state.json"
       ],
       "test_status": "pnpm test:run src/channels/telegram/adapter.test.ts src/config/schema.test.ts src/gateway/handlers/services.test.ts src/cli/doctor.test.ts + pnpm typecheck passing"
+    },
+    "webchat-slash-command-agent-fastpath-fix": {
+      "status": "completed",
+      "date": "2026-02-19",
+      "updated": "2026-02-19",
+      "summary": "Fixed WebChat slash command reliability by routing /reset, /compact, /usage, /status, and /model through agent.send command metadata fast-path instead of mixed local RPC shortcuts. This resolves /model returning unknown and keeps command behavior aligned with backend command registry.",
+      "files_modified": [
+        "src/gateway/ui/pages/chat.js",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm typecheck + pnpm test:run src/commands/registry.test.ts src/commands/builtin/index.test.ts passing"
     }
   },
   "overall_progress": {

src/gateway/ui/pages/chat.js

@@ -368,6 +368,20 @@ function showSystemMessage(content) {
   scrollToBottom();
 }
 
+async function executeAgentSlashCommand(client, command, commandArgs = '') {
+  const normalizedArgs = (commandArgs ?? '').trim();
+  const message = normalizedArgs ? `/${command} ${normalizedArgs}` : `/${command}`;
+  const metadata = {
+    isCommand: true,
+    command,
+    ...(normalizedArgs ? { commandArgs: normalizedArgs } : {}),
+  };
+
+  const stream = client.stream('agent.send', { message, metadata });
+  const done = await stream.result;
+  return done?.content ?? done?.text ?? '';
+}
+
 async function handleSlashCommand(cmd, client) {
   switch (cmd.type) {
     case 'help': {
@@ -381,7 +395,7 @@ async function handleSlashCommand(cmd, client) {
         '| `/compact` | Ask the agent to compact context |',
         '| `/usage` | Show token usage stats |',
         '| `/status` | Show system health |',
-        '| `/model` | Show current model info |',
+        '| `/model [tier|provider]` | Show or set model tier/provider |',
         '',
         'Type `/` to see autocomplete suggestions.',
       ];
@@ -391,14 +405,9 @@ async function handleSlashCommand(cmd, client) {
 
     case 'reset': {
       try {
-        // Send reset command via metadata
-        const stream = client.stream('agent.send', {
-          message: '/reset',
-          metadata: { isCommand: true, command: 'reset' },
-        });
-        await stream.result;
+        const result = await executeAgentSlashCommand(client, 'reset');
         _elements.messages.innerHTML = '';
-        showSystemMessage('Session reset.');
+        showSystemMessage(result || 'Session reset.');
       } catch (err) {
         showSystemMessage(`Failed to reset: ${err.message}`);
       }
@@ -406,33 +415,19 @@ async function handleSlashCommand(cmd, client) {
     }
 
     case 'compact': {
-      // Send as a regular message — the agent will interpret the request
-      showSystemMessage('Requesting context compaction...');
-      return false; // Let it pass through as a normal message
+      try {
+        const result = await executeAgentSlashCommand(client, 'compact');
+        showSystemMessage(result || 'Compaction requested.');
+      } catch (err) {
+        showSystemMessage(`Failed to compact: ${err.message}`);
+      }
+      return true;
     }
 
     case 'usage': {
       try {
-        const result = await client.call('system.tokenUsage');
-        const sessions = result.sessions ?? [];
-        if (sessions.length === 0) {
-          showSystemMessage('No usage data available.');
-        } else {
-          const lines = ['**Token Usage**', ''];
-          let totalIn = 0, totalOut = 0, totalCalls = 0;
-          for (const s of sessions) {
-            totalIn += s.total?.inputTokens ?? 0;
-            totalOut += s.total?.outputTokens ?? 0;
-            totalCalls += s.total?.calls ?? 0;
-          }
-          lines.push(`**Input:** ${totalIn.toLocaleString()} tokens`);
-          lines.push(`**Output:** ${totalOut.toLocaleString()} tokens`);
-          lines.push(`**API Calls:** ${totalCalls}`);
-          if (sessions.length > 1) {
-            lines.push(`**Sessions:** ${sessions.length}`);
-          }
-          showSystemMessage(lines.join('\n'));
-        }
+        const result = await executeAgentSlashCommand(client, 'usage');
+        showSystemMessage(result || 'No usage data available.');
       } catch (err) {
         showSystemMessage(`Failed to fetch usage: ${err.message}`);
       }
@@ -441,24 +436,8 @@ async function handleSlashCommand(cmd, client) {
 
     case 'status': {
       try {
-        const result = await client.call('system.health');
-        const lines = [
-          '**System Status**',
-          '',
-          `**Uptime:** ${result.uptime ?? 'unknown'}`,
-          `**Status:** ${result.status ?? 'unknown'}`,
-        ];
-        if (result.channels) {
-          lines.push('', '**Channels:**');
-          for (const ch of result.channels) {
-            const dot = ch.status === 'connected' ? '\\*' : '-';
-            lines.push(`  ${dot} ${ch.name}: ${ch.status}`);
-          }
-        }
-        if (result.model) {
-          lines.push('', `**Model:** ${result.model}`);
-        }
-        showSystemMessage(lines.join('\n'));
+        const result = await executeAgentSlashCommand(client, 'status');
+        showSystemMessage(result || 'Status unavailable.');
       } catch (err) {
         showSystemMessage(`Failed to fetch status: ${err.message}`);
       }
@@ -467,9 +446,8 @@ async function handleSlashCommand(cmd, client) {
 
     case 'model': {
       try {
-        const result = await client.call('system.health');
-        const model = result.model ?? result.config?.model ?? 'unknown';
-        showSystemMessage(`**Current Model:** ${model}`);
+        const result = await executeAgentSlashCommand(client, 'model', cmd.args ?? '');
+        showSystemMessage(result || 'Model info unavailable.');
       } catch (err) {
         showSystemMessage(`Failed to fetch model info: ${err.message}`);
       }