diff --git a/packages/app/server/claude-proxy.ts b/packages/app/server/claude-proxy.ts
index f611b6fa..9766b4a5 100644
--- a/packages/app/server/claude-proxy.ts
+++ b/packages/app/server/claude-proxy.ts
@@ -326,6 +326,102 @@ async function streamViaAnthropicApi(
   }
 }
 
+/** Call OpenRouter but emit Anthropic-format SSE (for Claude provider fallback) */
+async function streamViaOpenRouterFallback(
+  model: string,
+  system: string | undefined,
+  messages: { role: string; content: string }[],
+  res: import('http').ServerResponse,
+): Promise<void> {
+  const orModel = model?.includes('opus') ? 'anthropic/claude-opus-4'
+    : model?.includes('haiku') ? 'anthropic/claude-haiku-4'
+    : 'anthropic/claude-sonnet-4'
+  const orMessages: { role: string; content: string }[] = []
+  if (system) orMessages.push({ role: 'system', content: system })
+  for (const m of messages) {
+    orMessages.push({ role: m.role, content: m.content })
+  }
+
+  let clientDisconnected = false
+  res.on('close', () => { clientDisconnected = true })
+
+  res.writeHead(200, {
+    'Content-Type': 'text/event-stream',
+    'Cache-Control': 'no-cache',
+    'Connection': 'keep-alive',
+    'Access-Control-Allow-Origin': '*',
+    'X-Accel-Buffering': 'no',
+  })
+
+  try {
+    const apiRes = await fetch('https://openrouter.ai/api/v1/chat/completions', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Authorization': `Bearer ${OPENROUTER_API_KEY}`,
+        'HTTP-Referer': APP_URL,
+        'X-Title': 'AIUI',
+      },
+      body: JSON.stringify({ model: orModel, messages: orMessages, stream: true }),
+      signal: AbortSignal.timeout(120000),
+    })
+
+    if (!apiRes.ok) {
+      const errBody = await apiRes.text()
+      if (!clientDisconnected) {
+        res.write(`data: ${JSON.stringify({ type: 'error', error: { message: `OpenRouter ${apiRes.status}: ${errBody.slice(0, 200)}` } })}\n\n`)
+        res.write('data: [DONE]\n\n')
+        res.end()
+      }
+      return
+    }
+
+    const reader = apiRes.body?.getReader()
+    if (!reader) {
+      if (!clientDisconnected) {
+        res.write('data: [DONE]\n\n')
+        res.end()
+      }
+      return
+    }
+
+    const decoder = new TextDecoder()
+    let buffer = ''
+    while (true) {
+      const { done, value } = await reader.read()
+      if (done || clientDisconnected) break
+      buffer += decoder.decode(value, { stream: true })
+      const lines = buffer.split('\n')
+      buffer = lines.pop() ?? ''
+      for (const line of lines) {
+        if (!line.startsWith('data: ')) continue
+        const payload = line.slice(6).trim()
+        if (payload === '[DONE]') continue
+        try {
+          const chunk = JSON.parse(payload)
+          const text = chunk.choices?.[0]?.delta?.content
+          if (text && !clientDisconnected) {
+            // Convert to Anthropic SSE format
+            res.write(`data: ${JSON.stringify({ type: 'content_block_delta', delta: { type: 'text_delta', text } })}\n\n`)
+          }
+        } catch { /* skip malformed chunks */ }
+      }
+    }
+
+    if (!clientDisconnected) {
+      res.write('data: [DONE]\n\n')
+      res.end()
+    }
+  } catch (err) {
+    console.error('[proxy] OpenRouter fallback error:', err)
+    if (!clientDisconnected) {
+      res.write(`data: ${JSON.stringify({ type: 'error', error: { message: `OpenRouter error: ${err instanceof Error ? err.message : String(err)}` } })}\n\n`)
+      res.write('data: [DONE]\n\n')
+      res.end()
+    }
+  }
+}
+
 async function streamOpenRouterProxy(
   reqBody: string,
   res: import('http').ServerResponse,
@@ -446,8 +542,17 @@ const server = createServer((req, res) => {
         return
       }
 
-      // Fallback: Claude CLI (works when logged in from a normal terminal)
-      console.log('[proxy] No API credential — falling back to Claude CLI')
+      // Fallback: OpenRouter (when no Anthropic credential available)
+      if (OPENROUTER_API_KEY) {
+        console.log('[proxy] No API credential — falling back to OpenRouter')
+        const lastMsg = (messages ?? []).slice(-1)[0]?.content?.slice(0, 60) ?? ''
+        console.log(`[proxy] → OpenRouter fallback "${lastMsg}..."`)
+        await streamViaOpenRouterFallback(model, system, messages ?? [], res)
+        return
+      }
+
+      // Last resort: Claude CLI (works when logged in from terminal)
+      console.log('[proxy] No API credential and no OpenRouter key — falling back to Claude CLI')
 
       const modelFlag = model?.includes('opus') ? 'opus'
         : model?.includes('haiku') ? 'haiku'
@@ -480,7 +585,6 @@ const server = createServer((req, res) => {
       console.log(`[proxy] → claude -p --model ${modelFlag}${webSearch ? ' [WebSearch]' : ''} "${lastUserMsg.slice(0, 60)}..."`)
 
       const procEnv = { ...process.env, NO_COLOR: '1', TERM: 'dumb' }
-      // Unset Claude Code session vars so the CLI can spawn inside a CC session
       delete procEnv.CLAUDECODE
       delete procEnv.CLAUDE_CODE
       delete procEnv.ANTHROPIC_CLAUDE_CODE
@@ -507,12 +611,11 @@ const server = createServer((req, res) => {
       let fullOutput = ''
       let clientDisconnected = false
 
-      // Hard timeout — if CLI produces no output in 30s, return an error
       const cliTimeout = setTimeout(() => {
         if (fullOutput.length === 0 && !clientDisconnected) {
           console.warn('[proxy] CLI timeout (30s no output) — killing process')
           proc.kill('SIGTERM')
-          res.write(`data: ${JSON.stringify({ type: 'error', error: { message: 'Claude CLI timed out. Check that the claude binary is working: ~/.local/bin/claude -p "hi"' } })}\n\n`)
+          res.write(`data: ${JSON.stringify({ type: 'error', error: { message: 'Claude CLI timed out. Set ANTHROPIC_API_KEY or VITE_OPENROUTER_API_KEY in .env.local' } })}\n\n`)
           res.write('data: [DONE]\n\n')
           res.end()
         }
@@ -588,6 +691,9 @@ server.listen(PORT, async () => {
     const mode = isOAuthToken(credential) ? 'OAuth (Max)' : 'API key'
     console.log(`  Auth: ${mode} (token ...${credential.slice(-8)})`)
     console.log(`  Mode: Direct Anthropic API (no CLI needed)`)
+  } else if (OPENROUTER_API_KEY) {
+    console.log(`  Auth: none found (Anthropic)`)
+    console.log(`  Fallback: OpenRouter (key ...${OPENROUTER_API_KEY.slice(-8)})`)
   } else {
     console.log(`  Auth: none found`)
     console.log(`  Checked: env vars, ~/.claude/.credentials.json, ~/.claude/settings.json`)