From e7329fec18b9ec05bc751e28132d33fc74f2b838 Mon Sep 17 00:00:00 2001
From: Nicolas Patry <patry.nicolas@protonmail.com>
Date: Tue, 29 Apr 2025 16:29:26 +0200
Subject: [PATCH] Fixing the router + template for Qwen3. (#3200)

---
 router/src/config.rs              | 1 +
 router/src/infer/chat_template.rs | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/router/src/config.rs b/router/src/config.rs
index 93b6f4fa..7c595e2d 100644
--- a/router/src/config.rs
+++ b/router/src/config.rs
@@ -414,6 +414,7 @@ pub enum Config {
     T5,
     DeepseekV2,
     DeepseekV3,
+    Qwen3,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
diff --git a/router/src/infer/chat_template.rs b/router/src/infer/chat_template.rs
index a6687203..b26b3824 100644
--- a/router/src/infer/chat_template.rs
+++ b/router/src/infer/chat_template.rs
@@ -41,6 +41,10 @@ impl ChatTemplate {
             "messages[0]['content'][0]['text']",
             "messages[0]['content']",
         );
+        //  Hack to fix Qwen3 templating.
+        //  It uses python notation to reverse lists, which do not exist in minijinja
+        //  so we're using the reverse filter instead.
+        let mutated_template = mutated_template.replace("[::-1]", "|reverse");
 
         let template_str = mutated_template.into_boxed_str();
         env.add_function("raise_exception", raise_exception);