diff --git a/apis/libai.lua b/apis/libai.lua
index 4285bb0..6cf3d66 100644
--- a/apis/libai.lua
+++ b/apis/libai.lua
@@ -2,6 +2,8 @@ local PING_PROMPT = 'reply with exactly: pong';
 
 local DEFAULT_TIMEOUT_SECONDS = 60;
 local MAX_TIMEOUT_SECONDS = 60;
+local DEFAULT_POLL_TIMEOUT_SECONDS = 300;
+local DEFAULT_POLL_INTERVAL_SECONDS = 2;
 local DEFAULT_LUA_EXEC_MAX_RETRIES = 2;
 local DEFAULT_LUA_EXEC_TIMEOUT_SECONDS = 5;
 
@@ -57,6 +59,13 @@ local function extractTextParts(parts)
   return table.concat(texts, '');
 end
 
+local function nowSeconds()
+  if os.epoch then
+    return os.epoch('utc') / 1000;
+  end
+  return os.clock();
+end
+
 local function tablePack(...)
   return { n = select('#', ...), ... };
 end
@@ -146,6 +155,8 @@ local function createAi(opts)
 
   local httpLib = opts.http or http;
   local settingsLib = opts.settings or settings;
+  local sleepFunc = opts.sleep or sleep;
+  local nowFunc = opts.now or nowSeconds;
 
   local api = {};
 
@@ -158,6 +169,22 @@ local function createAi(opts)
     return n;
   end
 
+  local function resolvePollTimeout(options)
+    local raw = options.pollTimeoutSeconds;
+    if raw == nil then raw = settingsLib.get('opencc.poll_timeout_seconds'); end
+    local n = tonumber(raw);
+    if not n or n <= 0 then n = DEFAULT_POLL_TIMEOUT_SECONDS; end
+    return n;
+  end
+
+  local function resolvePollInterval(options)
+    local raw = options.pollIntervalSeconds;
+    if raw == nil then raw = settingsLib.get('opencc.poll_interval_seconds'); end
+    local n = tonumber(raw);
+    if not n or n <= 0 then n = DEFAULT_POLL_INTERVAL_SECONDS; end
+    return n;
+  end
+
   local function resolveLuaExecMaxRetries(options)
     local n = tonumber(options.maxRetries);
     if n and n >= 0 then return math.floor(n); end
@@ -183,9 +210,68 @@ local function createAi(opts)
       username = username,
       password = password,
       timeoutSeconds = resolveTimeout(options),
+      pollTimeoutSeconds = resolvePollTimeout(options),
+      pollIntervalSeconds = resolvePollInterval(options),
     };
   end
 
+  local function createMessageId()
+    local t = math.floor(nowFunc() * 1000);
+    return 'cc_' .. tostring(t) .. '_' .. tostring(math.random(100000, 999999));
+  end
+
+  local function isMessageComplete(message)
+    if type(message) ~= 'table' or type(message.info) ~= 'table' then
+      return false;
+    end
+    if type(message.info.finish) == 'string' then
+      return true;
+    end
+    return type(message.info.time) == 'table' and message.info.time.completed ~= nil;
+  end
+
+  local function decodeMessage(body)
+    local decoded = textutils.unserializeJSON(body);
+    if type(decoded) ~= 'table' or type(decoded.parts) ~= 'table' then
+      return nil, 'reponse message invalide';
+    end
+    return decoded, nil;
+  end
+
+  local function handleMissingSession(persist)
+    if persist then
+      settingsLib.unset('opencc.session_id');
+      if settingsLib.save then settingsLib.save(); end
+    end
+    return false, 'session introuvable; lance: ai new <prompt>';
+  end
+
+  local doGet;
+  local doPost;
+
+  local function pollMessage(cfg, sessionId, messageId, persist)
+    local deadline = nowFunc() + cfg.pollTimeoutSeconds;
+    while true do
+      local body, code = doGet(cfg, '/session/' .. sessionId .. '/message/' .. messageId);
+      if not body then return false, code; end
+      if code == 404 then return handleMissingSession(persist); end
+      if code and code ~= 200 then
+        return false, 'erreur message: HTTP ' .. tostring(code);
+      end
+
+      local decoded, decodeErr = decodeMessage(body);
+      if not decoded then return false, decodeErr; end
+      local reply = extractTextParts(decoded.parts);
+      if reply ~= '' and isMessageComplete(decoded) then
+        return true, { reply = reply, sessionId = sessionId, messageId = messageId };
+      end
+      if nowFunc() >= deadline then
+        return false, 'delai depasse en attendant la reponse AI';
+      end
+      sleepFunc(cfg.pollIntervalSeconds);
+    end
+  end
+
   local function buildHeaders(cfg)
     local headers = {
       ['Content-Type'] = 'application/json',
@@ -211,7 +297,7 @@ local function createAi(opts)
     return body, code;
   end
 
-  local function doGet(cfg, path)
+  function doGet(cfg, path)
     return callHttp('get', {
       url = cfg.url .. path,
       headers = buildHeaders(cfg),
@@ -219,7 +305,7 @@ local function createAi(opts)
     });
   end
 
-  local function doPost(cfg, path, payload)
+  function doPost(cfg, path, payload)
     return callHttp('post', {
       url = cfg.url .. path,
       body = textutils.serializeJSON(payload),
@@ -286,32 +372,28 @@ local function createAi(opts)
       end
     end
 
-    local body, code = doPost(cfg, '/session/' .. sessionId .. '/message', {
+    local messageId = options.messageId or createMessageId();
+    local body, code = doPost(cfg, '/session/' .. sessionId .. '/prompt_async', {
+      messageID = messageId,
       parts = { { type = 'text', text = prompt } },
     });
     if not body then return false, code; end
     if code == 404 then
-      if persist then
-        settingsLib.unset('opencc.session_id');
-        if settingsLib.save then settingsLib.save(); end
-      end
-      return false, 'session introuvable; lance: ai new <prompt>';
+      return handleMissingSession(persist);
     end
-    if code and code ~= 200 then
+    if code and code ~= 204 and code ~= 200 then
       return false, 'erreur message: HTTP ' .. tostring(code);
     end
 
-    local decoded = textutils.unserializeJSON(body);
-    if type(decoded) ~= 'table' or type(decoded.parts) ~= 'table' then
-      return false, 'reponse message invalide';
+    if code == 200 and body and body ~= '' then
+      local decoded, decodeErr = decodeMessage(body);
+      if not decoded then return false, decodeErr; end
+      local reply = extractTextParts(decoded.parts);
+      if reply == '' then return false, 'reponse vide'; end
+      return true, { reply = reply, sessionId = sessionId, messageId = messageId };
     end
 
-    local reply = extractTextParts(decoded.parts);
-    if reply == '' then
-      return false, 'reponse vide';
-    end
-
-    return true, { reply = reply, sessionId = sessionId };
+    return pollMessage(cfg, sessionId, messageId, persist);
   end
 
   function api.createLuaExecutor(options)
diff --git a/docs/opencode_api.md b/docs/opencode_api.md
index 07eb16e..30248dc 100644
--- a/docs/opencode_api.md
+++ b/docs/opencode_api.md
@@ -100,6 +100,22 @@ Parts can include non-text types (`tool-call`, `step-start`, etc.) — collect a
 
 ---
 
+### `GET /session/:id/message/:messageID`
+
+Get a message by ID. `ai` uses this to poll async prompts until the assistant message has text parts and completion metadata.
+
+**Response** `200`:
+```json
+{
+  "info": { "id": "msg_xyz", "sessionID": "ses_abc123", "role": "assistant", "time": { "completed": 1234567890 } },
+  "parts": [
+    { "type": "text", "text": "the reply" }
+  ]
+}
+```
+
+---
+
 ### `DELETE /session/:id`
 
 Delete a session.
@@ -114,7 +130,9 @@ Abort a running generation.
 
 ### `POST /session/:id/prompt_async`
 
-Fire-and-forget variant. Returns `204` immediately; result arrives over the SSE stream.
+Fire-and-forget variant. Returns `204` immediately. Include `messageID` in the request body to make the assistant response addressable by `GET /session/:id/message/:messageID`.
+
+`ai` uses this endpoint by default to avoid `504` failures from the blocking `/message` endpoint when the LLM takes longer than one HTTP request timeout.
 
 ---
 
diff --git a/docs/opencode_server_guide.md b/docs/opencode_server_guide.md
index eec05ec..9c746cb 100644
--- a/docs/opencode_server_guide.md
+++ b/docs/opencode_server_guide.md
@@ -124,4 +124,5 @@ Set settings inside the harness before running, or inject them via the test API.
 | `missing prompt` | No prompt was passed | Run `ai <prompt>` or `ai ping` |
 | `session introuvable; lance: ai new <prompt>` | Session was deleted or server restarted | Run `ai new <prompt>` |
 | `erreur message: HTTP 504` | AI took too long | Retry; consider a faster model |
+| `delai depasse en attendant la reponse AI` | Async polling timed out | Increase `opencc.poll_timeout_seconds` or check opencode logs |
 | `reponse vide` | Reply had no text parts | Check opencode logs |
diff --git a/manifest.json b/manifest.json
index 5ccda29..fca3756 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,6 +1,6 @@
 {
   "name": "TrapOS",
-  "version": "0.6.2",
+  "version": "0.6.3",
   "branch": "next",
   "packages": [
     "trapos"
diff --git a/packages/index.json b/packages/index.json
index d6acbbf..cfc547a 100644
--- a/packages/index.json
+++ b/packages/index.json
@@ -5,8 +5,8 @@
     "trapos-boot": "0.2.2",
     "trapos-net": "0.2.1",
     "trapos-ui": "0.2.2",
-    "trapos-ai": "0.5.1",
+    "trapos-ai": "0.5.2",
     "trapos-sandbox": "0.1.0",
-    "trapos": "0.6.2"
+    "trapos": "0.6.3"
   }
 }
diff --git a/packages/trapos-ai/ccpm.json b/packages/trapos-ai/ccpm.json
index a629bf9..d45617f 100644
--- a/packages/trapos-ai/ccpm.json
+++ b/packages/trapos-ai/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "trapos-ai",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "description": "TrapOS AI client for opencode serve",
   "dependencies": ["trapos-core"],
   "files": [
diff --git a/packages/trapos/ccpm.json b/packages/trapos/ccpm.json
index c4fd092..d1cbb44 100644
--- a/packages/trapos/ccpm.json
+++ b/packages/trapos/ccpm.json
@@ -1,6 +1,6 @@
 {
   "name": "trapos",
-  "version": "0.6.2",
+  "version": "0.6.3",
   "description": "TrapOS full install meta-package",
   "dependencies": ["trapos-boot", "trapos-net", "trapos-ui", "trapos-test", "trapos-ai"],
   "files": [],
diff --git a/programs/ai.lua b/programs/ai.lua
index db20027..250f78d 100644
--- a/programs/ai.lua
+++ b/programs/ai.lua
@@ -24,6 +24,9 @@ local function printUsage()
   print('  opencc.username   (default: opencode)');
   print('  opencc.password   (Basic Auth password)');
   print('  opencc.session_id (auto-managed)');
+  print('  opencc.timeout_seconds       (per HTTP call, max 60)');
+  print('  opencc.poll_timeout_seconds  (default: 300)');
+  print('  opencc.poll_interval_seconds (default: 2)');
 end
 
 local function joinArgs(start)
diff --git a/tests/ai.lua b/tests/ai.lua
index a983257..4f7878b 100644
--- a/tests/ai.lua
+++ b/tests/ai.lua
@@ -72,7 +72,18 @@ end
 
 local function messageResp(reply)
   return response(200, textutils.serializeJSON({
-    info = {},
+    info = { time = { completed = 1 } },
+    parts = { { type = 'text', text = reply } },
+  }));
+end
+
+local function asyncResp()
+  return response(204, '');
+end
+
+local function pendingMessageResp(reply)
+  return response(200, textutils.serializeJSON({
+    info = { time = {} },
     parts = { { type = 'text', text = reply } },
   }));
 end
@@ -187,7 +198,7 @@ testlib.test('ask creates session then sends message when no session_id', functi
   testlib.assertEquals(result.sessionId, 'ses_new');
   testlib.assertEquals(#httpStub.postCalls, 2);
   testlib.assertTrue(string.find(httpStub.postCalls[1].url, '/session', 1, true) ~= nil);
-  testlib.assertTrue(string.find(httpStub.postCalls[2].url, '/session/ses_new/message', 1, true) ~= nil);
+  testlib.assertTrue(string.find(httpStub.postCalls[2].url, '/session/ses_new/prompt_async', 1, true) ~= nil);
 end);
 
 testlib.test('ask creates cc-ai titled sessions', function()
@@ -233,7 +244,7 @@ testlib.test('ask reuses existing session_id without creating a new session', fu
 
   testlib.assertTrue(ok);
   testlib.assertEquals(#httpStub.postCalls, 1);
-  testlib.assertTrue(string.find(httpStub.postCalls[1].url, '/session/ses_existing/message', 1, true) ~= nil);
+  testlib.assertTrue(string.find(httpStub.postCalls[1].url, '/session/ses_existing/prompt_async', 1, true) ~= nil);
 end);
 
 testlib.test('ask sends exact prompt text', function()
@@ -255,6 +266,55 @@ testlib.test('ask sends exact prompt text', function()
   testlib.assertEquals(body.parts[1].text, 'my prompt');
 end);
 
+testlib.test('ask polls async message until completion', function()
+  local httpStub = fakeHttp(
+    { sessionResp('ses_1'), asyncResp() },
+    { pendingMessageResp('partial'), messageResp('reply') }
+  );
+  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
+  local sleeps = {};
+  local ai = createAi({
+    http = httpStub,
+    settings = settingsStub,
+    now = function() return 10; end,
+    sleep = function(n) sleeps[#sleeps + 1] = n; end,
+  });
+
+  local ok, result = ai.ask('hello', { messageId = 'msg_1', pollIntervalSeconds = 3 });
+
+  testlib.assertTrue(ok, tostring(result));
+  testlib.assertEquals(result.reply, 'reply');
+  testlib.assertEquals(result.messageId, 'msg_1');
+  testlib.assertEquals(#httpStub.getCalls, 2);
+  testlib.assertTrue(string.find(httpStub.getCalls[1].url, '/session/ses_1/message/msg_1', 1, true) ~= nil);
+  testlib.assertEquals(sleeps[1], 3);
+end);
+
+testlib.test('ask polling times out', function()
+  local httpStub = fakeHttp(
+    { sessionResp('ses_1'), asyncResp() },
+    { pendingMessageResp('partial'), pendingMessageResp('partial') }
+  );
+  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
+  local now = 0;
+  local ai = createAi({
+    http = httpStub,
+    settings = settingsStub,
+    now = function() return now; end,
+    sleep = function(n) now = now + n; end,
+  });
+
+  local ok, err = ai.ask('hello', {
+    messageId = 'msg_1',
+    pollTimeoutSeconds = 1,
+    pollIntervalSeconds = 1,
+  });
+
+  testlib.assertTrue(not ok);
+  testlib.assertTrue(string.find(err, 'delai depasse', 1, true) ~= nil);
+  testlib.assertEquals(#httpStub.getCalls, 2);
+end);
+
 testlib.test('ask rejects missing prompt without HTTP calls', function()
   local httpStub = fakeHttp({}, {});
   local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });