[router][tool parser] Modify tool parser to return both normal text and tool...

[router][tool parser] Modify tool parser to return both normal text and tool calls (non-stream) (#10995)

sgl-router/benches/tool_parser_benchmark.rs

@@ -409,7 +409,7 @@ fn bench_concurrent_parsing(c: &mut Criterion) {
                                     let result =
                                         rt.block_on(async { parser.parse_complete(input).await });
 
-                                    if let Ok(tools) = result {
+                                    if let Ok((_normal_text, tools)) = result {
                                         total_p.fetch_add(tools.len() as u64, Ordering::Relaxed);
                                     }
                                 }

sgl-router/src/reasoning_parser/traits.rs

@@ -3,7 +3,7 @@ use std::fmt;
 /// Result of parsing text for reasoning content.
 #[derive(Debug, Clone, Default, PartialEq)]
 pub struct ParserResult {
-    /// The normal text outside of reasoning blocks.
+    /// The normal text outside reasoning blocks.
     pub normal_text: String,
 
     /// The extracted reasoning text from within reasoning blocks.

sgl-router/src/routers/grpc/router.rs

@@ -804,7 +804,7 @@ impl GrpcRouter {
                 .get_parser(&original_request.model)
             {
                 match parser.parse_complete(&processed_text).await {
-                    Ok(parsed_tool_calls) => {
+                    Ok((normal_text, parsed_tool_calls)) => {
                         if !parsed_tool_calls.is_empty() {
                             let spec_tool_calls = parsed_tool_calls
                                 .into_iter()
@@ -821,7 +821,7 @@ impl GrpcRouter {
                                 })
                                 .collect();
                             tool_calls = Some(spec_tool_calls);
-                            processed_text = String::new();
+                            processed_text = normal_text;
                         }
                     }
                     Err(e) => {

sgl-router/src/tool_parser/parsers/deepseek_parser.rs

@@ -50,14 +50,6 @@ impl DeepSeekParser {
         text.contains("<｜tool▁calls▁begin｜>")
     }
 
-    /// Extract all tool call blocks from text
-    fn extract_tool_calls<'a>(&self, text: &'a str) -> Vec<&'a str> {
-        self.tool_call_extractor
-            .find_iter(text)
-            .map(|m| m.as_str())
-            .collect()
-    }
-
     /// Parse a single tool call block
     fn parse_tool_call(&self, block: &str) -> ToolParserResult<Option<ToolCall>> {
         if let Some(captures) = self.func_detail_extractor.captures(block) {
@@ -115,23 +107,42 @@ impl Default for DeepSeekParser {
 
 #[async_trait]
 impl ToolParser for DeepSeekParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains DeepSeek format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
-        // Extract all tool call blocks
-        let tool_blocks = self.extract_tool_calls(text);
+        // Collect matches with positions and parse tools in one pass
+        let matches: Vec<_> = self.tool_call_extractor.find_iter(text).collect();
         let mut tools = Vec::new();
 
-        for block in tool_blocks {
-            if let Some(tool) = self.parse_tool_call(block)? {
+        for mat in matches.iter() {
+            if let Some(tool) = self.parse_tool_call(mat.as_str())? {
                 tools.push(tool);
             }
         }
 
-        Ok(tools)
+        // Extract normal text using first and last match positions
+        let normal_text = if tools.is_empty() || matches.is_empty() {
+            text.to_string()
+        } else {
+            let first_start = matches[0].start();
+            let last_end = matches.last().unwrap().end();
+            let before = if first_start > 0 {
+                &text[..first_start]
+            } else {
+                ""
+            };
+            let after = if last_end < text.len() {
+                &text[last_end..]
+            } else {
+                ""
+            };
+            format!("{}{}", before, after)
+        };
+
+        Ok((normal_text, tools))
     }
 
     async fn parse_incremental(
@@ -241,10 +252,10 @@ mod tests {
 {"location": "Tokyo", "units": "celsius"}
 ```<｜tool▁call▁end｜><｜tool▁calls▁end｜>More text"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Tokyo"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Tokyo"));
     }
 
     #[tokio::test]
@@ -259,12 +270,12 @@ mod tests {
 {"location": "Paris"}
 ```<｜tool▁call▁end｜><｜tool▁calls▁end｜>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert_eq!(result[1].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Tokyo"));
-        assert!(result[1].function.arguments.contains("Paris"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert_eq!(tools[1].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Tokyo"));
+        assert!(tools[1].function.arguments.contains("Paris"));
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/glm4_moe_parser.rs

@@ -130,21 +130,42 @@ impl Default for Glm4MoeParser {
 
 #[async_trait]
 impl ToolParser for Glm4MoeParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains GLM-4 MoE format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
-        // Extract all tool call blocks
+        // Collect matches with positions and parse tools in one pass
+        let matches: Vec<_> = self.tool_call_extractor.find_iter(text).collect();
         let mut tools = Vec::new();
-        for mat in self.tool_call_extractor.find_iter(text) {
+
+        for mat in matches.iter() {
             if let Some(tool) = self.parse_tool_call(mat.as_str())? {
                 tools.push(tool);
             }
         }
 
-        Ok(tools)
+        // Extract normal text using first and last match positions
+        let normal_text = if tools.is_empty() {
+            text.to_string()
+        } else {
+            let first_start = matches[0].start();
+            let last_end = matches.last().unwrap().end();
+            let before = if first_start > 0 {
+                &text[..first_start]
+            } else {
+                ""
+            };
+            let after = if last_end < text.len() {
+                &text[last_end..]
+            } else {
+                ""
+            };
+            format!("{}{}", before, after)
+        };
+
+        Ok((normal_text, tools))
     }
 
     async fn parse_incremental(
@@ -232,11 +253,12 @@ mod tests {
 <arg_value>2024-06-27</arg_value>
 </tool_call>More text"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Beijing"));
-        assert!(result[0].function.arguments.contains("2024-06-27"));
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Beijing"));
+        assert!(tools[0].function.arguments.contains("2024-06-27"));
+        assert_eq!(normal_text, "Some text\nMore text"); // Text before and after tool call
     }
 
     #[tokio::test]
@@ -251,12 +273,13 @@ mod tests {
 <arg_value>Shanghai</arg_value>
 </tool_call>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert_eq!(result[1].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Beijing"));
-        assert!(result[1].function.arguments.contains("Shanghai"));
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert_eq!(tools[1].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Beijing"));
+        assert!(tools[1].function.arguments.contains("Shanghai"));
+        assert_eq!(normal_text, ""); // Pure tool calls, no normal text
     }
 
     #[tokio::test]
@@ -271,12 +294,13 @@ mod tests {
 <arg_value>test</arg_value>
 </tool_call>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "process_data");
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(normal_text, ""); // Pure tool call, no normal text
+        assert_eq!(tools[0].function.name, "process_data");
 
         // Parse arguments to check types
-        let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["count"], 42);
         assert_eq!(args["active"], true);
         assert_eq!(args["name"], "test");

sgl-router/src/tool_parser/parsers/gpt_oss_parser.rs

@@ -71,10 +71,10 @@ impl Default for GptOssParser {
 
 #[async_trait]
 impl ToolParser for GptOssParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains GPT-OSS format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
         let mut tools = Vec::new();
@@ -119,7 +119,7 @@ impl ToolParser for GptOssParser {
             }
         }
 
-        Ok(tools)
+        Ok((String::new(), tools)) // GPT-OSS parser returns empty normal text
     }
 
     async fn parse_incremental(
@@ -239,10 +239,10 @@ mod tests {
 <|channel|>commentary to=functions.get_weather<|constrain|>json<|message|>{"location": "San Francisco"}<|call|>
 More text"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("San Francisco"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("San Francisco"));
     }
 
     #[tokio::test]
@@ -251,12 +251,12 @@ More text"#;
         let input = r#"<|channel|>commentary to=functions.get_weather<|constrain|>json<|message|>{"location": "Paris"}<|call|>commentary
 <|channel|>commentary to=functions.search<|constrain|>json<|message|>{"query": "Paris tourism"}<|call|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert_eq!(result[1].function.name, "search");
-        assert!(result[0].function.arguments.contains("Paris"));
-        assert!(result[1].function.arguments.contains("Paris tourism"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert_eq!(tools[1].function.name, "search");
+        assert!(tools[0].function.arguments.contains("Paris"));
+        assert!(tools[1].function.arguments.contains("Paris tourism"));
     }
 
     #[tokio::test]
@@ -264,9 +264,9 @@ More text"#;
         let parser = GptOssParser::new();
         let input = r#"<|start|>assistant<|channel|>commentary to=functions.test<|constrain|>json<|message|>{"key": "value"}<|call|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "test");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "test");
     }
 
     #[tokio::test]
@@ -275,10 +275,10 @@ More text"#;
         let input =
             r#"<|channel|>commentary to=functions.get_time<|constrain|>json<|message|>{}<|call|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_time");
-        assert_eq!(result[0].function.arguments, "{}");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_time");
+        assert_eq!(tools[0].function.arguments, "{}");
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/json_parser.rs

@@ -88,64 +88,65 @@ impl JsonParser {
         content.trim()
     }
 
-    /// Try to extract a JSON object or array from text that may contain other content
-    fn extract_json_from_text(&self, text: &str) -> Option<String> {
-        // Look for JSON object starting with {
-        if let Some(start) = text.find('{') {
-            let mut depth = 0;
+    /// Try to extract a first valid JSON object or array from text that may contain other content
+    /// Returns (json_string, normal_text) where normal_text is text before and after the JSON
+    fn extract_json_from_text(&self, text: &str) -> Option<(String, String)> {
         let mut in_string = false;
-            let mut escape_next = false;
+        let mut escape = false;
+        let mut stack: Vec<char> = Vec::with_capacity(8);
+        let mut start: Option<usize> = None;
 
-            for (i, ch) in text[start..].char_indices() {
-                if escape_next {
-                    escape_next = false;
+        for (i, ch) in text.char_indices() {
+            if escape {
+                escape = false;
                 continue;
             }
 
             match ch {
-                    '\\' if in_string => escape_next = true,
-                    '"' if !in_string => in_string = true,
-                    '"' if in_string => in_string = false,
-                    '{' if !in_string => depth += 1,
-                    '}' if !in_string => {
-                        depth -= 1;
-                        if depth == 0 {
-                            return Some(text[start..start + i + 1].to_string());
-                        }
-                    }
-                    _ => {}
-                }
-            }
+                '\\' if in_string => escape = true,
+                '"' => in_string = !in_string,
+                _ if in_string => {}
+                '{' | '[' => {
+                    if start.is_none() {
+                        start = Some(i);
+                    }
+                    stack.push(ch);
+                }
+                '}' | ']' => {
+                    let Some(open) = stack.pop() else {
+                        // Stray closer - reset and continue looking for next valid JSON
+                        start = None;
+                        continue;
+                    };
+
+                    let valid = (open == '{' && ch == '}') || (open == '[' && ch == ']');
+                    if !valid {
+                        // Mismatch - reset and continue looking
+                        start = None;
+                        stack.clear();
+                        continue;
                     }
 
-        // Look for JSON array starting with [
-        if let Some(start) = text.find('[') {
-            let mut depth = 0;
-            let mut in_string = false;
-            let mut escape_next = false;
+                    if stack.is_empty() {
+                        let s = start.unwrap();
+                        let e = i + ch.len_utf8();
+                        let potential_json = &text[s..e];
 
-            for (i, ch) in text[start..].char_indices() {
-                if escape_next {
-                    escape_next = false;
+                        // Validate that this is actually valid JSON before returning
+                        if serde_json::from_str::<Value>(potential_json).is_ok() {
+                            let json = potential_json.to_string();
+                            let normal = format!("{}{}", &text[..s], &text[e..]);
+                            return Some((json, normal));
+                        } else {
+                            // Not valid JSON, reset and continue looking
+                            start = None;
                             continue;
                         }
-
-                match ch {
-                    '\\' if in_string => escape_next = true,
-                    '"' if !in_string => in_string = true,
-                    '"' if in_string => in_string = false,
-                    '[' if !in_string => depth += 1,
-                    ']' if !in_string => {
-                        depth -= 1;
-                        if depth == 0 {
-                            return Some(text[start..start + i + 1].to_string());
                     }
                 }
                 _ => {}
             }
         }
-        }
-
         None
     }
 
@@ -241,16 +242,20 @@ impl Default for JsonParser {
 
 #[async_trait]
 impl ToolParser for JsonParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if we have multiple start tokens (e.g., multiple <|python_tag|> markers)
         if !self.token_config.start_tokens.is_empty() {
             let start_token = &self.token_config.start_tokens[0];
             if !start_token.is_empty() && text.matches(start_token).count() > 1 {
                 // We have multiple occurrences of the start token
                 let mut all_tools = Vec::new();
+                let mut all_normal_text = String::new();
                 let mut remaining = text;
 
                 while let Some(start_pos) = remaining.find(start_token.as_str()) {
+                    // Add text before this start token to normal text
+                    all_normal_text.push_str(&remaining[..start_pos]);
+
                     // Extract content after this start token
                     let after_token = &remaining[start_pos + start_token.len()..];
 
@@ -264,12 +269,19 @@ impl ToolParser for JsonParser {
                     let json_content = &after_token[..end_pos];
 
                     // Try to extract and parse JSON from this segment
-                    if let Some(extracted) = self.extract_json_from_text(json_content) {
+                    if let Some((extracted, segment_normal_text)) =
+                        self.extract_json_from_text(json_content)
+                    {
                         if let Ok(value) = serde_json::from_str::<Value>(&extracted) {
                             if let Ok(tools) = self.parse_json_value(&value) {
                                 all_tools.extend(tools);
                             }
                         }
+                        // Add the normal text from this segment
+                        all_normal_text.push_str(&segment_normal_text);
+                    } else {
+                        // If no JSON found, add the entire content as normal text
+                        all_normal_text.push_str(json_content);
                     }
 
                     // Move to the next segment
@@ -279,9 +291,10 @@ impl ToolParser for JsonParser {
                     }
                 }
 
-                if !all_tools.is_empty() {
-                    return Ok(all_tools);
-                }
+                // Add any remaining text
+                all_normal_text.push_str(remaining);
+
+                return Ok((all_normal_text, all_tools));
             }
         }
 
@@ -290,21 +303,30 @@ impl ToolParser for JsonParser {
 
         // Try to parse as JSON first
         match serde_json::from_str::<Value>(json_content) {
-            Ok(value) => self.parse_json_value(&value),
+            Ok(value) => {
+                let tools = self.parse_json_value(&value)?;
+                Ok((String::new(), tools))
+            }
             Err(_) => {
                 // If parse failed, check if we have multiple JSON objects separated by the configured separator
-                // This handles cases like: {"name": "func1", ...};{"name": "func2", ...}
+                // Only do this if we can reasonably expect multiple complete JSON objects
+                // (i.e., text starts and ends with JSON-like structure)
                 if !self.token_config.separator.is_empty()
                     && json_content.contains(&self.token_config.separator)
+                    && json_content.trim().starts_with('{')
+                    && json_content.trim().ends_with('}')
                 {
                     let mut all_tools = Vec::new();
 
                     // Split by separator and try to parse each part
                     let parts: Vec<&str> =
                         json_content.split(&self.token_config.separator).collect();
+                    let mut normal_parts = Vec::new();
+
                     for part in parts {
                         let trimmed = part.trim();
                         if trimmed.is_empty() {
+                            normal_parts.push(trimmed.to_string());
                             continue;
                         }
 
@@ -313,32 +335,40 @@ impl ToolParser for JsonParser {
                             if let Ok(tools) = self.parse_json_value(&value) {
                                 all_tools.extend(tools);
                             }
-                        } else if let Some(extracted) = self.extract_json_from_text(trimmed) {
+                            normal_parts.push(trimmed.to_string());
+                        } else if let Some((extracted, part_normal_text)) =
+                            self.extract_json_from_text(trimmed)
+                        {
                             // Try extracting JSON from this part
                             if let Ok(value) = serde_json::from_str::<Value>(&extracted) {
                                 if let Ok(tools) = self.parse_json_value(&value) {
                                     all_tools.extend(tools);
                                 }
                             }
+                            normal_parts.push(part_normal_text);
+                        } else {
+                            normal_parts.push(trimmed.to_string());
                         }
                     }
 
-                    if !all_tools.is_empty() {
-                        return Ok(all_tools);
-                    }
+                    // Rejoin with the original separator to preserve it
+                    let all_normal_text = normal_parts.join(&self.token_config.separator);
+
+                    return Ok((all_normal_text, all_tools));
                 }
 
-                // If no wrapper tokens configured and parse failed,
-                // try to extract JSON from mixed text
+                // If no wrapper tokens configured and parse failed, try to extract JSON from mixed text
                 if self.token_config.start_tokens.is_empty() {
-                    if let Some(extracted) = self.extract_json_from_text(text) {
-                        if let Ok(value) = serde_json::from_str::<Value>(&extracted) {
-                            return self.parse_json_value(&value);
+                    if let Some((extracted_json, normal_text)) = self.extract_json_from_text(text) {
+                        if let Ok(value) = serde_json::from_str::<Value>(&extracted_json) {
+                            let tools = self.parse_json_value(&value)?;
+                            return Ok((normal_text, tools));
                         }
                     }
                 }
-                // Not valid JSON, return empty
-                Ok(vec![])
+
+                // No valid JSON found, return original text as normal text
+                Ok((text.to_string(), vec![]))
             }
         }
     }
@@ -538,9 +568,41 @@ mod tests {
         let parser = JsonParser::new();
         let input = r#"{"name": "get_weather", "arguments": {"location": "San Francisco"}}"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "get_weather");
+        assert_eq!(normal_text, ""); // Pure JSON should have no normal text
+    }
+
+    #[tokio::test]
+    async fn test_extract_json_with_normal_text() {
+        let parser = JsonParser::new();
+
+        // Test extraction of JSON from mixed text
+        let input =
+            r#"Here is some text before {"name": "test", "arguments": {}} and some text after."#;
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "test");
+        assert_eq!(
+            normal_text,
+            "Here is some text before  and some text after."
+        );
+    }
+
+    #[tokio::test]
+    async fn test_extract_json_array_with_normal_text() {
+        let parser = JsonParser::new();
+
+        // Test extraction of JSON array from mixed text
+        let input = r#"Prefix text [{"name": "func1", "arguments": {}}, {"name": "func2", "arguments": {}}] suffix text"#;
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+
+        assert_eq!(tool_calls.len(), 2);
+        assert_eq!(tool_calls[0].function.name, "func1");
+        assert_eq!(tool_calls[1].function.name, "func2");
+        assert_eq!(normal_text, "Prefix text  suffix text");
     }
 
     #[tokio::test]
@@ -551,10 +613,11 @@ mod tests {
             {"name": "search", "arguments": {"query": "news"}}
         ]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert_eq!(result[1].function.name, "search");
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 2);
+        assert_eq!(tool_calls[0].function.name, "get_weather");
+        assert_eq!(tool_calls[1].function.name, "search");
+        assert_eq!(normal_text, ""); // Pure JSON should have no normal text
     }
 
     #[tokio::test]
@@ -562,10 +625,11 @@ mod tests {
         let parser = JsonParser::new();
         let input = r#"{"name": "calculate", "parameters": {"x": 10, "y": 20}}"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "calculate");
-        assert!(result[0].function.arguments.contains("10"));
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "calculate");
+        assert!(tool_calls[0].function.arguments.contains("10"));
+        assert_eq!(normal_text, ""); // Pure JSON should have no normal text
     }
 
     #[tokio::test]
@@ -577,9 +641,38 @@ mod tests {
         });
 
         let input = r#"<tool>{"name": "test", "arguments": {}}</tool>"#;
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "test");
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "test");
+        assert_eq!(normal_text, ""); // Wrapper tokens with no extra text
+    }
+
+    #[tokio::test]
+    async fn test_parse_with_start_token_invalid_json() {
+        let parser = JsonParser::with_config(TokenConfig {
+            start_tokens: vec!["<|python_tag|>".to_string()],
+            end_tokens: vec!["".to_string()],
+            separator: ";".to_string(),
+        });
+
+        let input = r#"Hello world <|python_tag|>this is not valid json at all"#;
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 0);
+        assert_eq!(normal_text, input); // Should return entire original text when JSON parsing fails
+    }
+
+    #[tokio::test]
+    async fn test_parse_with_normal_text() {
+        let parser = JsonParser::new();
+        let input = r#"Here is the weather data: {"name": "get_weather", "arguments": {"location": "SF"}} Let me know if you need more info."#;
+
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "get_weather");
+        assert_eq!(
+            normal_text,
+            "Here is the weather data:  Let me know if you need more info."
+        ); // Normal text is now extracted when JSON is found in mixed content
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/kimik2_parser.rs

@@ -79,16 +79,18 @@ impl Default for KimiK2Parser {
 
 #[async_trait]
 impl ToolParser for KimiK2Parser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains Kimi K2 format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
+        // Collect matches with positions and parse tools in one pass
+        let matches: Vec<_> = self.tool_call_extractor.captures_iter(text).collect();
         let mut tools = Vec::new();
 
-        // Extract all tool calls
-        for captures in self.tool_call_extractor.captures_iter(text) {
+        // Extract all tool calls using collected matches
+        for captures in matches.iter() {
             if let (Some(id_match), Some(args_match)) = (
                 captures.name("tool_call_id"),
                 captures.name("function_arguments"),
@@ -116,7 +118,26 @@ impl ToolParser for KimiK2Parser {
             }
         }
 
-        Ok(tools)
+        // Extract normal text using first and last match positions
+        let normal_text = if tools.is_empty() || matches.is_empty() {
+            text.to_string()
+        } else {
+            let first_start = matches[0].get(0).unwrap().start();
+            let last_end = matches.last().unwrap().get(0).unwrap().end();
+            let before = if first_start > 0 {
+                &text[..first_start]
+            } else {
+                ""
+            };
+            let after = if last_end < text.len() {
+                &text[last_end..]
+            } else {
+                ""
+            };
+            format!("{}{}", before, after)
+        };
+
+        Ok((normal_text, tools))
     }
 
     async fn parse_incremental(
@@ -227,10 +248,10 @@ mod tests {
 <|tool_call_begin|>functions.get_weather:0<|tool_call_argument_begin|>{"location": "Tokyo", "units": "celsius"}<|tool_call_end|>
 <|tool_calls_section_end|>More text"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Tokyo"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Tokyo"));
     }
 
     #[tokio::test]
@@ -241,10 +262,10 @@ mod tests {
 <|tool_call_begin|>functions.calculate:1<|tool_call_argument_begin|>{"expression": "2+2"}<|tool_call_end|>
 <|tool_calls_section_end|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "search");
-        assert_eq!(result[1].function.name, "calculate");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "search");
+        assert_eq!(tools[1].function.name, "calculate");
     }
 
     #[tokio::test]
@@ -254,9 +275,9 @@ mod tests {
 <|tool_call_begin|> functions.test:0 <|tool_call_argument_begin|> {"key": "value"} <|tool_call_end|>
 <|tool_calls_section_end|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "test");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "test");
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/llama_parser.rs

@@ -42,22 +42,32 @@ impl Default for LlamaParser {
 
 #[async_trait]
 impl ToolParser for LlamaParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // First try with the configured python_tag parser
-        let result = self.json_parser.parse_complete(text).await?;
-
-        if !result.is_empty() {
-            return Ok(result);
+        let (_json_normal_text, tools) = self.json_parser.parse_complete(text).await?;
+
+        if !tools.is_empty() {
+            // Extract normal text before the python tag
+            // JsonParser doesn't preserve normal text for single start tokens, so we do it manually
+            let normal_text = if let Some(tag_pos) = text.find("<|python_tag|>") {
+                text[..tag_pos].to_string()
+            } else {
+                String::new()
+            };
+            return Ok((normal_text, tools));
         }
 
         // If no results and text starts with '{', try plain JSON
         if text.trim_start().starts_with('{') {
             // Create a temporary plain JSON parser
             let plain_parser = JsonParser::new();
-            return plain_parser.parse_complete(text).await;
+            let (_json_normal_text, tools) = plain_parser.parse_complete(text).await?;
+            // For plain JSON, don't extract normal text (consistent with JsonParser behavior)
+            return Ok((String::new(), tools));
         }
 
-        Ok(vec![])
+        // No tool calls found, return original text as normal text
+        Ok((text.to_string(), vec![]))
     }
 
     async fn parse_incremental(
@@ -99,10 +109,11 @@ mod tests {
         let parser = LlamaParser::new();
         let input = r#"<|python_tag|>{"name": "search", "arguments": {"query": "weather"}}"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "search");
-        assert!(result[0].function.arguments.contains("weather"));
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "search");
+        assert!(tool_calls[0].function.arguments.contains("weather"));
+        assert_eq!(normal_text, ""); // Pure python_tag with JSON should have no normal text
     }
 
     #[tokio::test]
@@ -110,9 +121,10 @@ mod tests {
         let parser = LlamaParser::new();
         let input = r#"{"name": "calculate", "arguments": {"x": 5, "y": 10}}"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "calculate");
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "calculate");
+        assert_eq!(normal_text, ""); // Pure JSON should have no normal text
     }
 
     #[tokio::test]
@@ -120,9 +132,10 @@ mod tests {
         let parser = LlamaParser::new();
         let input = r#"Let me help you with that. <|python_tag|>{"name": "get_time", "arguments": {"timezone": "UTC"}}"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_time");
+        let (normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tool_calls.len(), 1);
+        assert_eq!(tool_calls[0].function.name, "get_time");
+        assert_eq!(normal_text, "Let me help you with that. ");
     }
 
     #[test]
@@ -141,15 +154,15 @@ mod tests {
         // Note: Llama 3.2 doesn't handle multiple calls well
         let input = r#"<|python_tag|>{"name": "func1", "arguments": {"x": 1}};"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
+        let (_normal_text, tool_calls) = parser.parse_complete(input).await.unwrap();
 
         // We expect this to either parse the first JSON object or fail gracefully
         // Since the semicolon makes it invalid JSON, it will likely return empty
         // This is acceptable as Llama 3.2 doesn't reliably support parallel calls
 
         // If it parses anything, it should be func1
-        if !result.is_empty() {
-            assert_eq!(result[0].function.name, "func1");
+        if !tool_calls.is_empty() {
+            assert_eq!(tool_calls[0].function.name, "func1");
         }
     }
 }

sgl-router/src/tool_parser/parsers/mistral_parser.rs

@@ -38,6 +38,10 @@ impl MistralParser {
     /// - Escape sequences
     /// - Bracket depth
     fn extract_json_array<'a>(&self, text: &'a str) -> Option<&'a str> {
+        self.extract_json_array_with_pos(text).map(|(_, json)| json)
+    }
+
+    fn extract_json_array_with_pos<'a>(&self, text: &'a str) -> Option<(usize, &'a str)> {
         const BOT_TOKEN: &str = "[TOOL_CALLS] [";
 
         // Find the start of the token
@@ -78,7 +82,7 @@ impl MistralParser {
                     bracket_count -= 1;
                     if bracket_count == 0 {
                         // Found the matching closing bracket
-                        return Some(&text[json_start..=i]);
+                        return Some((start_idx, &text[json_start..=i]));
                     }
                 }
             }
@@ -154,18 +158,31 @@ impl Default for MistralParser {
 
 #[async_trait]
 impl ToolParser for MistralParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains Mistral format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
-        // Extract JSON array from Mistral format
-        if let Some(json_array) = self.extract_json_array(text) {
-            self.parse_json_array(json_array)
+        // Extract JSON array from Mistral format with position
+        if let Some((start_idx, json_array)) = self.extract_json_array_with_pos(text) {
+            // Extract normal text before BOT_TOKEN
+            let normal_text_before = if start_idx > 0 {
+                text[..start_idx].to_string()
+            } else {
+                String::new()
+            };
+
+            match self.parse_json_array(json_array) {
+                Ok(tools) => Ok((normal_text_before, tools)),
+                Err(_) => {
+                    // If JSON parsing fails, return the original text as normal text
+                    Ok((text.to_string(), vec![]))
+                }
+            }
         } else {
             // Markers present but no complete array found
-            Ok(vec![])
+            Ok((text.to_string(), vec![]))
         }
     }
 
@@ -291,10 +308,10 @@ mod tests {
         let parser = MistralParser::new();
         let input = r#"[TOOL_CALLS] [{"name": "get_weather", "arguments": {"location": "Paris", "units": "celsius"}}]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Paris"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Paris"));
     }
 
     #[tokio::test]
@@ -305,10 +322,10 @@ mod tests {
             {"name": "calculate", "arguments": {"expression": "2 + 2"}}
         ]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "search");
-        assert_eq!(result[1].function.name, "calculate");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "search");
+        assert_eq!(tools[1].function.name, "calculate");
     }
 
     #[tokio::test]
@@ -316,11 +333,11 @@ mod tests {
         let parser = MistralParser::new();
         let input = r#"[TOOL_CALLS] [{"name": "process", "arguments": {"data": [1, 2, [3, 4]], "config": {"nested": [5, 6]}}}]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "process");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "process");
         // JSON serialization removes spaces, so check for [3,4] without spaces
-        assert!(result[0].function.arguments.contains("[3,4]"));
+        assert!(tools[0].function.arguments.contains("[3,4]"));
     }
 
     #[tokio::test]
@@ -328,9 +345,9 @@ mod tests {
         let parser = MistralParser::new();
         let input = r#"[TOOL_CALLS] [{"name": "echo", "arguments": {"message": "He said \"Hello [World]\""}}]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "echo");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "echo");
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/pythonic_parser.rs

@@ -45,7 +45,8 @@ impl PythonicParser {
     }
 
     /// Extract tool calls using bracket counting (similar to MistralParser)
-    fn extract_tool_calls(&self, text: &str) -> Option<String> {
+    /// Returns extracted tool call group with [] and normal content
+    fn extract_tool_calls(&self, text: &str) -> Option<(String, String)> {
         // Find the start of a tool call list - look for [ followed by a function name
         let chars: Vec<char> = text.chars().collect();
 
@@ -103,7 +104,11 @@ impl PythonicParser {
                                 // Found the matching bracket
                                 let extracted: String = chars[start_idx..=i].iter().collect();
                                 if extracted.contains('(') && extracted.contains(')') {
-                                    return Some(extracted);
+                                    // Calculate normal text by removing the tool call portion
+                                    let before = &text[..start_idx];
+                                    let after = &text[(i + 1)..];
+                                    let normal_text = format!("{}{}", before, after);
+                                    return Some((extracted, normal_text));
                                 }
                             }
                         }
@@ -260,11 +265,11 @@ impl PythonicParser {
 
 #[async_trait]
 impl ToolParser for PythonicParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         let cleaned = Self::strip_special_tokens(text);
 
         // Extract tool calls using bracket counting
-        if let Some(tool_calls_text) = self.extract_tool_calls(&cleaned) {
+        if let Some((tool_calls_text, normal_text)) = self.extract_tool_calls(&cleaned) {
             // Remove the outer brackets
             let tool_calls_str = &tool_calls_text[1..tool_calls_text.len() - 1];
 
@@ -318,9 +323,9 @@ impl ToolParser for PythonicParser {
                 }
             }
 
-            Ok(calls)
+            Ok((normal_text, calls))
         } else {
-            Ok(vec![])
+            Ok((text.to_string(), vec![]))
         }
     }
 
@@ -336,11 +341,11 @@ impl ToolParser for PythonicParser {
         // Try to parse if we have a complete tool call
         let cleaned = Self::strip_special_tokens(&state.buffer);
         if self.extract_tool_calls(&cleaned).is_some() {
-            let result = self.parse_complete(&state.buffer).await?;
-            if !result.is_empty() {
+            let (_normal_text, tools) = self.parse_complete(&state.buffer).await?;
+            if !tools.is_empty() {
                 state.buffer.clear();
                 return Ok(StreamResult::ToolComplete(
-                    result.into_iter().next().unwrap(),
+                    tools.into_iter().next().unwrap(),
                 ));
             }
         }
@@ -369,11 +374,11 @@ mod tests {
         let parser = PythonicParser::new();
         let input = r#"[search_web(query="Rust programming", max_results=5)]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "search_web");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "search_web");
 
-        let args: Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["query"], "Rust programming");
         assert_eq!(args["max_results"], 5);
     }
@@ -383,10 +388,10 @@ mod tests {
         let parser = PythonicParser::new();
         let input = r#"[get_weather(city="Tokyo"), search(query="news")]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert_eq!(result[1].function.name, "search");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert_eq!(tools[1].function.name, "search");
     }
 
     #[tokio::test]
@@ -394,10 +399,10 @@ mod tests {
         let parser = PythonicParser::new();
         let input = r#"[test(flag=True, disabled=False, optional=None)]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
 
-        let args: Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["flag"], true);
         assert_eq!(args["disabled"], false);
         assert_eq!(args["optional"], Value::Null);
@@ -408,11 +413,11 @@ mod tests {
         let parser = PythonicParser::new();
         let input = r#"<|python_start|>[calculate(x=10, y=20)]<|python_end|>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "calculate");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "calculate");
 
-        let args: Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["x"], 10);
         assert_eq!(args["y"], 20);
     }
@@ -422,12 +427,41 @@ mod tests {
         let parser = PythonicParser::new();
         let input = r#"[get_weather(city="London", units="celsius")]"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
 
-        let args: Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["city"], "London");
         assert_eq!(args["units"], "celsius");
     }
+
+    #[tokio::test]
+    async fn test_normal_text_extraction() {
+        let parser = PythonicParser::new();
+
+        // Test with text before and after
+        let input = r#"Please check the weather [get_weather(city="Tokyo")] and let me know."#;
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert_eq!(normal_text, "Please check the weather  and let me know.");
+
+        // Test with only normal text (no tool calls)
+        let input_no_tools = "This is just normal text without any tool calls.";
+        let (normal_text, tools) = parser.parse_complete(input_no_tools).await.unwrap();
+
+        assert_eq!(tools.len(), 0);
+        assert_eq!(normal_text, input_no_tools);
+
+        // Test with multiple tool calls in single bracket group and normal text
+        let input_multiple = r#"First, [search(query="rust"), calculate(x=5, y=10)] please."#;
+        let (normal_text, tools) = parser.parse_complete(input_multiple).await.unwrap();
+
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "search");
+        assert_eq!(tools[1].function.name, "calculate");
+        assert_eq!(normal_text, "First,  please.");
+    }
 }

sgl-router/src/tool_parser/parsers/qwen_parser.rs

@@ -128,32 +128,51 @@ impl Default for QwenParser {
 
 #[async_trait]
 impl ToolParser for QwenParser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains Qwen format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
-        // Extract all tool call blocks
-        let tool_blocks = self.extract_tool_calls(text);
+        // Collect matches with positions and parse tools in one pass
+        let matches: Vec<_> = self.extractor.captures_iter(text).collect();
         let mut tools = Vec::new();
 
-        for (index, json_str) in tool_blocks.iter().enumerate() {
-            // Parse each JSON block
-            match serde_json::from_str::<Value>(json_str.trim()) {
+        for (index, captures) in matches.iter().enumerate() {
+            if let Some(json_str) = captures.get(1) {
+                match serde_json::from_str::<Value>(json_str.as_str().trim()) {
                     Ok(value) => {
                         if let Some(tool) = self.parse_single_object(&value, index)? {
                             tools.push(tool);
                         }
                     }
                     Err(_) => {
-                    // Skip malformed JSON blocks
-                    continue;
+                        // JSON parsing failed, might be incomplete
+                    }
                 }
             }
         }
 
-        Ok(tools)
+        // Extract normal text using first and last match positions
+        let normal_text = if tools.is_empty() {
+            text.to_string()
+        } else {
+            let first_start = matches[0].get(0).unwrap().start();
+            let last_end = matches.last().unwrap().get(0).unwrap().end();
+            let before = if first_start > 0 {
+                &text[..first_start]
+            } else {
+                ""
+            };
+            let after = if last_end < text.len() {
+                &text[last_end..]
+            } else {
+                ""
+            };
+            format!("{}{}", before, after)
+        };
+
+        Ok((normal_text, tools))
     }
 
     async fn parse_incremental(
@@ -276,10 +295,11 @@ mod tests {
 {"name": "get_weather", "arguments": {"location": "Beijing", "units": "celsius"}}
 </tool_call>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Beijing"));
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Beijing"));
+        assert_eq!(normal_text, ""); // Pure tool call, no normal text
     }
 
     #[tokio::test]
@@ -292,10 +312,11 @@ mod tests {
 {"name": "calculate", "arguments": {"expression": "2 + 2"}}
 </tool_call>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "search");
-        assert_eq!(result[1].function.name, "calculate");
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "search");
+        assert_eq!(tools[1].function.name, "calculate");
+        assert_eq!(normal_text, ""); // Pure tool calls, no normal text
     }
 
     #[tokio::test]
@@ -307,9 +328,13 @@ mod tests {
 </tool_call>
 Here are the results."#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_info");
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_info");
+        assert_eq!(
+            normal_text,
+            "Let me help you with that.\n\nHere are the results."
+        );
     }
 
     #[tokio::test]
@@ -329,10 +354,11 @@ Here are the results."#;
 }
 </tool_call>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "process_data");
-        assert!(result[0].function.arguments.contains("nested"));
+        let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "process_data");
+        assert!(tools[0].function.arguments.contains("nested"));
+        assert_eq!(normal_text, ""); // Pure tool call, no normal text
     }
 
     #[test]

sgl-router/src/tool_parser/parsers/step3_parser.rs

@@ -157,10 +157,10 @@ impl Default for Step3Parser {
 
 #[async_trait]
 impl ToolParser for Step3Parser {
-    async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
+    async fn parse_complete(&self, text: &str) -> ToolParserResult<(String, Vec<ToolCall>)> {
         // Check if text contains Step3 format
         if !self.has_tool_markers(text) {
-            return Ok(vec![]);
+            return Ok((text.to_string(), vec![]));
         }
 
         // Find the tool calls section
@@ -170,6 +170,7 @@ impl ToolParser for Step3Parser {
             // Find the end of tool calls section
             if let Some(end_pos) = text[search_from..].find("<｜tool_calls_end｜>") {
                 let tool_section = &text[search_from..search_from + end_pos];
+                let end_abs = search_from + end_pos + "<｜tool_calls_end｜>".len();
 
                 // Extract all tool call blocks
                 let mut tools = Vec::new();
@@ -179,11 +180,24 @@ impl ToolParser for Step3Parser {
                     }
                 }
 
-                return Ok(tools);
+                // Extract normal text before start and after end
+                let before = if start_pos > 0 {
+                    &text[..start_pos]
+                } else {
+                    ""
+                };
+                let after = if end_abs < text.len() {
+                    &text[end_abs..]
+                } else {
+                    ""
+                };
+                let normal_text = format!("{}{}", before, after);
+
+                return Ok((normal_text, tools));
             }
         }
 
-        Ok(vec![])
+        Ok((text.to_string(), vec![]))
     }
 
     async fn parse_incremental(
@@ -289,11 +303,11 @@ mod tests {
 </steptml:invoke><｜tool_call_end｜>
 <｜tool_calls_end｜>More text"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "get_weather");
-        assert!(result[0].function.arguments.contains("Tokyo"));
-        assert!(result[0].function.arguments.contains("celsius"));
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "get_weather");
+        assert!(tools[0].function.arguments.contains("Tokyo"));
+        assert!(tools[0].function.arguments.contains("celsius"));
     }
 
     #[tokio::test]
@@ -308,10 +322,10 @@ mod tests {
 </steptml:invoke><｜tool_call_end｜>
 <｜tool_calls_end｜>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 2);
-        assert_eq!(result[0].function.name, "search");
-        assert_eq!(result[1].function.name, "calculate");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 2);
+        assert_eq!(tools[0].function.name, "search");
+        assert_eq!(tools[1].function.name, "calculate");
     }
 
     #[tokio::test]
@@ -326,12 +340,12 @@ mod tests {
 </steptml:invoke><｜tool_call_end｜>
 <｜tool_calls_end｜>"#;
 
-        let result = parser.parse_complete(input).await.unwrap();
-        assert_eq!(result.len(), 1);
-        assert_eq!(result[0].function.name, "process_data");
+        let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+        assert_eq!(tools.len(), 1);
+        assert_eq!(tools[0].function.name, "process_data");
 
         // Parse arguments to check types
-        let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+        let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
         assert_eq!(args["count"], 42);
         assert_eq!(args["active"], true);
         assert_eq!(args["rate"], 1.5);

sgl-router/src/tool_parser/traits.rs

@@ -9,7 +9,8 @@ use async_trait::async_trait;
 #[async_trait]
 pub trait ToolParser: Send + Sync {
     /// Parse complete tool calls from final output
-    async fn parse_complete(&self, output: &str) -> ToolParserResult<Vec<ToolCall>>;
+    /// Returns (remaining_normal_text, tool_calls) tuple
+    async fn parse_complete(&self, output: &str) -> ToolParserResult<(String, Vec<ToolCall>)>;
 
     /// Parse tool calls from model output (streaming)
     async fn parse_incremental(

sgl-router/tests/tool_parser_deepseek.rs

@@ -13,11 +13,11 @@ async fn test_deepseek_complete_parsing() {
 ```<｜tool▁call▁end｜><｜tool▁calls▁end｜>
 The weather in Tokyo is..."#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "get_weather");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "get_weather");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["location"], "Tokyo");
     assert_eq!(args["units"], "celsius");
 }
@@ -37,10 +37,10 @@ async fn test_deepseek_multiple_tools() {
 ```<｜tool▁call▁end｜>
 <｜tool▁calls▁end｜>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 2);
-    assert_eq!(result[0].function.name, "search");
-    assert_eq!(result[1].function.name, "translate");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 2);
+    assert_eq!(tools[0].function.name, "search");
+    assert_eq!(tools[1].function.name, "translate");
 }
 
 #[tokio::test]
@@ -96,11 +96,11 @@ async fn test_deepseek_nested_json() {
 }
 ```<｜tool▁call▁end｜><｜tool▁calls▁end｜>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "process");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "process");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert!(args["data"]["nested"]["deep"].is_array());
 }
 
@@ -134,10 +134,10 @@ async fn test_deepseek_malformed_json_handling() {
 ```<｜tool▁call▁end｜>
 <｜tool▁calls▁end｜>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
     // Only the valid tool call should be parsed
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "valid");
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "valid");
 }
 
 #[tokio::test]
@@ -151,9 +151,9 @@ async fn test_normal_text_extraction() {
 {"location": "Tokyo"}
 ```<｜tool▁call▁end｜><｜tool▁calls▁end｜>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "get_weather");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "get_weather");
 
     // TODO: Verify normal text extraction when parser returns it
     // In Python: normal_text = "Let me help you with that."
@@ -174,8 +174,8 @@ async fn test_multiple_tool_calls() {
 ```<｜tool▁call▁end｜>
 <｜tool▁calls▁end｜><｜end▁of▁sentence｜>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 2);
-    assert_eq!(result[0].function.name, "get_weather");
-    assert_eq!(result[1].function.name, "get_weather");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 2);
+    assert_eq!(tools[0].function.name, "get_weather");
+    assert_eq!(tools[1].function.name, "get_weather");
 }

sgl-router/tests/tool_parser_edge_cases.rs

@@ -16,9 +16,9 @@ async fn test_empty_input() {
         let parser = registry
             .get_parser(&format!("test-{}", parser_name))
             .unwrap();
-        let result = parser.parse_complete("").await.unwrap();
+        let (_normal_text, tools) = parser.parse_complete("").await.unwrap();
         assert_eq!(
-            result.len(),
+            tools.len(),
             0,
             "Parser {} should return empty for empty input",
             parser_name
@@ -32,7 +32,12 @@ async fn test_plain_text_no_tools() {
 
     let json_parser = JsonParser::new();
     assert_eq!(
-        json_parser.parse_complete(plain_text).await.unwrap().len(),
+        json_parser
+            .parse_complete(plain_text)
+            .await
+            .unwrap()
+            .1
+            .len(),
         0
     );
 
@@ -42,13 +47,19 @@ async fn test_plain_text_no_tools() {
             .parse_complete(plain_text)
             .await
             .unwrap()
+            .1
             .len(),
         0
     );
 
     let qwen_parser = QwenParser::new();
     assert_eq!(
-        qwen_parser.parse_complete(plain_text).await.unwrap().len(),
+        qwen_parser
+            .parse_complete(plain_text)
+            .await
+            .unwrap()
+            .1
+            .len(),
         0
     );
 
@@ -58,6 +69,7 @@ async fn test_plain_text_no_tools() {
             .parse_complete(plain_text)
             .await
             .unwrap()
+            .1
             .len(),
         0
     );
@@ -74,9 +86,9 @@ async fn test_incomplete_json() {
     ];
 
     for input in incomplete_cases {
-        let result = json_parser.parse_complete(input).await.unwrap();
+        let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
         assert_eq!(
-            result.len(),
+            tools.len(),
             0,
             "Should not parse incomplete JSON: {}",
             input
@@ -106,9 +118,9 @@ async fn test_malformed_mistral() {
 
     for input in malformed_cases {
         // Parser might return error or empty vec for malformed input
-        if let Ok(result) = parser.parse_complete(input).await {
+        if let Ok((_normal_text, tools)) = parser.parse_complete(input).await {
             assert_eq!(
-                result.len(),
+                tools.len(),
                 0,
                 "Should not parse malformed Mistral: {}",
                 input
@@ -124,13 +136,13 @@ async fn test_missing_required_fields() {
 
     // Missing name field
     let input = r#"{"arguments": {"x": 1}}"#;
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 0, "Should not parse without name field");
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0, "Should not parse without name field");
 
     // Name is not a string
     let input = r#"{"name": 123, "arguments": {}}"#;
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 0, "Should not parse with non-string name");
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0, "Should not parse with non-string name");
 }
 
 #[tokio::test]
@@ -143,11 +155,11 @@ async fn test_very_long_strings() {
         long_string
     );
 
-    let result = json_parser.parse_complete(&input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "test");
+    let (_normal_text, tools) = json_parser.parse_complete(&input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "test");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["data"].as_str().unwrap().len(), 10000);
 }
 
@@ -158,10 +170,10 @@ async fn test_unicode_edge_cases() {
     // Various Unicode characters including emojis, CJK, RTL text
     let input = r#"{"name": "translate", "arguments": {"text": "Hello 世界 🌍 مرحبا עולם"}}"#;
 
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["text"], "Hello 世界 🌍 مرحبا עולם");
 }
 
@@ -169,16 +181,16 @@ async fn test_unicode_edge_cases() {
 async fn test_nested_brackets_in_strings() {
     let mistral_parser = MistralParser::new();
     let input = r#"[TOOL_CALLS] [{"name": "echo", "arguments": {"text": "Array: [1, 2, 3]"}}]"#;
-    let result = mistral_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let (_normal_text, tools) = mistral_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["text"], "Array: [1, 2, 3]");
 
     let pythonic_parser = PythonicParser::new();
     let input = r#"[echo(text="List: [a, b, c]")]"#;
-    let result = pythonic_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let (_normal_text, tools) = pythonic_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["text"], "List: [a, b, c]");
 }
 
@@ -191,9 +203,9 @@ async fn test_multiple_formats_in_text() {
     And some more text with <tool_call> tags.
     "#;
 
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "actual_tool");
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "actual_tool");
 }
 
 #[tokio::test]
@@ -202,10 +214,10 @@ async fn test_escaped_characters() {
 
     let input = r#"{"name": "write", "arguments": {"content": "Line 1\nLine 2\r\nLine 3\tTabbed\\Backslash\"Quote"}}"#;
 
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     let content = args["content"].as_str().unwrap();
     assert!(content.contains('\n'));
     assert!(content.contains('\t'));
@@ -229,10 +241,10 @@ async fn test_numeric_edge_cases() {
         }
     }"#;
 
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["int"], 42);
     assert_eq!(args["float"], 123.456);
     assert_eq!(args["scientific"], 0.000123);
@@ -254,10 +266,10 @@ async fn test_null_and_boolean_values() {
         }
     }"#;
 
-    let result = json_parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = json_parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["enabled"], true);
     assert_eq!(args["disabled"], false);
     assert_eq!(args["optional"], serde_json::Value::Null);

sgl-router/tests/tool_parser_fallback.rs

+//! Tests for tool parser fallback behavior
+//!
+//! When tool call parsing fails, the original text should be preserved as normal text
+//! rather than being lost. This ensures graceful degradation.
+
+use sglang_router_rs::tool_parser::{
+    DeepSeekParser, JsonParser, LlamaParser, MistralParser, QwenParser, ToolParser,
+};
+
+#[tokio::test]
+async fn test_json_parser_invalid_json_returns_as_normal_text() {
+    let parser = JsonParser::new();
+
+    // Malformed JSON should be returned as normal text (note: commas may be processed)
+    let input = r#"{"name": "test", "arguments": invalid json here}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(
+        normal_text,
+        r#"{"name": "test", "arguments": invalid json here}"#
+    );
+
+    // Plain text with no JSON structure should be returned as normal text
+    let input = "This is just plain text that should not be parsed as a tool call";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input);
+
+    // Text that looks like it might have JSON but doesn't should be returned as normal text
+    let input = "The user said: {something} but it's not valid JSON";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input);
+}
+
+#[tokio::test]
+async fn test_qwen_parser_invalid_format_returns_as_normal_text() {
+    let parser = QwenParser::new();
+
+    // Missing closing tag
+    let input = r#"<tool_call>
+{"name": "test", "arguments": {}}
+This text is missing the closing tag"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve original text when no valid tools found
+
+    // Malformed JSON inside valid tags
+    let input = r#"<tool_call>
+{"name": "test", "arguments": invalid}
+</tool_call>"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    // When JSON parsing fails but tags are present, it should preserve the original text
+    assert_eq!(normal_text, input);
+
+    // Plain text without any tool markers
+    let input = "This is a regular response without any tool calls.";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should return original text when no markers found
+}
+
+#[tokio::test]
+async fn test_llama_parser_invalid_format_returns_as_normal_text() {
+    let parser = LlamaParser::new();
+
+    // Invalid JSON after python_tag
+    let input = r#"<|python_tag|>{"name": "test", "arguments": invalid}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve original text when parsing fails
+
+    // Plain text without markers or JSON
+    let input = "Just explaining something without any function calls.";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should return original text
+
+    // Text with python_tag but completely invalid content
+    let input = r#"Here's my response <|python_tag|>not even close to JSON"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve everything when parsing fails
+}
+
+#[tokio::test]
+async fn test_mistral_parser_invalid_format_returns_as_normal_text() {
+    let parser = MistralParser::new();
+
+    // Missing closing bracket
+    let input = r#"[TOOL_CALLS] [{"name": "test", "arguments": {}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve original text when parsing fails
+
+    // Invalid JSON in tool calls section
+    let input = r#"[TOOL_CALLS] [{"name": invalid json}]"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve original text when parsing fails
+
+    // Plain text
+    let input = "No tool calls here, just regular text.";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should return original text
+}
+
+#[tokio::test]
+async fn test_deepseek_parser_invalid_format_returns_as_normal_text() {
+    let parser = DeepSeekParser::new();
+
+    // Invalid JSON after emoji marker
+    let input = r#"🤔[{"name": "test", "arguments": malformed}]"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should preserve original text when parsing fails
+
+    // Emoji but no JSON array
+    let input = "🤔 Just thinking about this problem...";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should return original text
+
+    // No emoji marker at all
+    let input = "Regular response without any special markers.";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Should return original text
+}
+
+#[tokio::test]
+async fn test_mixed_valid_and_invalid_content() {
+    let parser = QwenParser::new();
+
+    // Text with one valid tool call and one invalid
+    let input = r#"Let me help you with that.
+<tool_call>
+{"name": "valid_tool", "arguments": {"x": 1}}
+</tool_call>
+And here's another one:
+<tool_call>
+{"name": "invalid_tool", "arguments": malformed}
+</tool_call>
+That's all!"#;
+
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1); // Should extract the valid tool
+    assert_eq!(tools[0].function.name, "valid_tool");
+    // Normal text should contain the text around the valid tool call
+    assert!(normal_text.contains("Let me help you"));
+    assert!(normal_text.contains("That's all!"));
+}
+
+#[tokio::test]
+async fn test_partial_tool_markers() {
+    // Test cases where tool markers are incomplete or cut off
+
+    let parser = QwenParser::new();
+    let input = "<tool_call>\nThis looks like it might be a tool call but it's not";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input);
+
+    let parser = MistralParser::new();
+    let input = "[TOOL_CALLS] But then nothing follows...";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input);
+
+    let parser = LlamaParser::new();
+    let input = "Starting a response <|python_tag|> but no JSON";
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input);
+}
+
+#[tokio::test]
+async fn test_escaped_json_like_content() {
+    // Test that JSON-like content in regular text doesn't get parsed as tools
+
+    let parser = JsonParser::new();
+    let input = r#"The user typed: {"name": "example"} but this is just quoted text"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    // JsonParser should extract the valid JSON and return normal text
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "example");
+    assert_eq!(normal_text, "The user typed:  but this is just quoted text");
+
+    let parser = QwenParser::new();
+    let input = r#"The syntax is: <tool_call>
+{"name": "example"}
+</tool_call> - that's how you format it"#;
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    // This actually contains valid tool call syntax, so it should parse
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "example");
+}
+
+#[tokio::test]
+async fn test_unicode_and_special_chars_in_failed_parsing() {
+    let parser = QwenParser::new();
+
+    // Unicode in malformed tool calls
+    let input = r#"<tool_call>
+{"name": "测试", "arguments": 🚀 invalid}
+</tool_call>"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    // Should handle Unicode properly in the fallback text
+    assert!(!normal_text.is_empty() || normal_text == input);
+
+    // Special characters that might confuse parsers
+    let input = r#"Response: <tool_call>{"name": "test\n\t", "arguments": {"]}"}</tool_call>"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    // This might or might not parse depending on JSON handling of escape sequences
+    if tools.is_empty() {
+        assert!(!normal_text.is_empty() || normal_text == input);
+    }
+}
+
+#[tokio::test]
+async fn test_very_long_invalid_input() {
+    let parser = JsonParser::new();
+
+    // Generate a very long string that looks like it might be JSON but isn't
+    let mut input = String::from("{\"name\": \"test\", \"arguments\": {");
+    for i in 0..1000 {
+        input.push_str(&format!("\"field{}\": \"value{}\", ", i, i));
+    }
+    input.push_str("\"final\": incomplete"); // Don't close the JSON properly
+
+    let (normal_text, tools) = parser.parse_complete(&input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(normal_text, input); // Invalid JSON should be returned as normal text
+}
+
+#[tokio::test]
+async fn test_almost_valid_tool_calls() {
+    // Test tool calls that are almost valid but have small issues
+
+    let parser = JsonParser::new();
+
+    // Missing closing quote should be returned as normal text
+    let input = r#"{"name": "test", "arguments": {"key": "value}}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0);
+    assert_eq!(
+        normal_text,
+        r#"{"name": "test", "arguments": {"key": "value}}"#
+    );
+
+    // Extra comma
+    let input = r#"{"name": "test", "arguments": {},}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    // Some JSON parsers might accept trailing commas
+    if tools.is_empty() {
+        assert_eq!(normal_text, r#"{"name": "test", "arguments": ,}"#);
+    }
+
+    // Wrong quote types
+    let input = r#"{'name': 'test', 'arguments': {}}"#;
+    let (normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0); // Standard JSON requires double quotes
+    assert_eq!(normal_text, r#"{'name': 'test', 'arguments': }"#);
+}

sgl-router/tests/tool_parser_glm4_moe.rs

@@ -15,11 +15,11 @@ async fn test_glm4_complete_parsing() {
 </tool_call>
 The weather will be..."#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "get_weather");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "get_weather");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["city"], "Beijing");
     assert_eq!(args["date"], "2024-12-25");
 }
@@ -39,10 +39,10 @@ async fn test_glm4_multiple_tools() {
 <arg_value>zh</arg_value>
 </tool_call>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 2);
-    assert_eq!(result[0].function.name, "search");
-    assert_eq!(result[1].function.name, "translate");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 2);
+    assert_eq!(tools[0].function.name, "search");
+    assert_eq!(tools[1].function.name, "translate");
 }
 
 #[tokio::test]
@@ -62,10 +62,10 @@ async fn test_glm4_type_conversion() {
 <arg_value>string value</arg_value>
 </tool_call>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["count"], 42);
     assert_eq!(args["rate"], 1.5);
     assert_eq!(args["enabled"], true);
@@ -138,10 +138,10 @@ async fn test_glm4_python_literal_values() {
 <arg_value>None</arg_value>
 </tool_call>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["debug"], true);
     assert_eq!(args["verbose"], false);
     assert_eq!(args["optional"], serde_json::Value::Null);
@@ -160,11 +160,11 @@ async fn test_python_literals() {
 <arg_value>None</arg_value>
 </tool_call>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "test_func");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "test_func");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["bool_true"], true);
     assert_eq!(args["bool_false"], false);
     assert_eq!(args["none_val"], serde_json::Value::Null);
@@ -181,10 +181,10 @@ async fn test_nested_values() {
 <arg_value>[1, 2, 3]</arg_value>
 </tool_call>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert!(args["data"].is_object());
     assert!(args["list"].is_array());
 }

sgl-router/tests/tool_parser_gpt_oss.rs

@@ -10,11 +10,11 @@ async fn test_gpt_oss_complete_parsing() {
 <|channel|>commentary to=functions.search<|constrain|>json<|message|>{"query": "rust programming", "limit": 10}<|call|>
 Here are the results..."#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "search");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "search");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert_eq!(args["query"], "rust programming");
     assert_eq!(args["limit"], 10);
 }
@@ -26,10 +26,10 @@ async fn test_gpt_oss_multiple_tools() {
     let input = r#"<|channel|>commentary to=functions.get_weather<|constrain|>json<|message|>{"location": "Paris"}<|call|>commentary
 <|channel|>commentary to=functions.search<|constrain|>json<|message|>{"query": "Paris tourism"}<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 2);
-    assert_eq!(result[0].function.name, "get_weather");
-    assert_eq!(result[1].function.name, "search");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 2);
+    assert_eq!(tools[0].function.name, "get_weather");
+    assert_eq!(tools[1].function.name, "search");
 }
 
 #[tokio::test]
@@ -39,10 +39,10 @@ async fn test_gpt_oss_with_namespace() {
     let input = r#"<|channel|>commentary to=api.users.create<|constrain|>json<|message|>{"name": "John", "email": "john@example.com"}<|call|>
 <|channel|>commentary to=tools.calculator.add<|constrain|>json<|message|>{"x": 10, "y": 20}<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 2);
-    assert_eq!(result[0].function.name, "create"); // Should extract last part
-    assert_eq!(result[1].function.name, "add");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 2);
+    assert_eq!(tools[0].function.name, "create"); // Should extract last part
+    assert_eq!(tools[1].function.name, "add");
 }
 
 #[tokio::test]
@@ -51,9 +51,9 @@ async fn test_gpt_oss_with_assistant_prefix() {
 
     let input = r#"<|start|>assistant<|channel|>commentary to=functions.test<|constrain|>json<|message|>{"key": "value"}<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "test");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "test");
 }
 
 #[tokio::test]
@@ -63,10 +63,10 @@ async fn test_gpt_oss_empty_args() {
     let input =
         r#"<|channel|>commentary to=functions.get_time<|constrain|>json<|message|>{}<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "get_time");
-    assert_eq!(result[0].function.arguments, "{}");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "get_time");
+    assert_eq!(tools[0].function.arguments, "{}");
 }
 
 #[tokio::test]
@@ -127,9 +127,9 @@ async fn test_gpt_oss_with_whitespace() {
 
     let input = r#"<|channel|>commentary to=functions.test  <|constrain|>json<|message|>{"key": "value"}<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "test");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "test");
 }
 
 #[tokio::test]
@@ -145,11 +145,11 @@ async fn test_gpt_oss_complex_json() {
     }
 }<|call|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "process");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "process");
 
-    let args: serde_json::Value = serde_json::from_str(&result[0].function.arguments).unwrap();
+    let args: serde_json::Value = serde_json::from_str(&tools[0].function.arguments).unwrap();
     assert!(args["nested"]["data"].is_array());
     assert_eq!(args["nested"]["config"]["enabled"], true);
 }
@@ -161,8 +161,8 @@ async fn test_commentary_without_function() {
     // Python should extract commentary as normal text
     let input = r#"<|channel|>commentary<|message|>**Action plan**: 1. Do X 2. Do Y<|end|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 0); // No tool calls
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 0); // No tool calls
                                 // TODO: Verify normal text = "**Action plan**: 1. Do X 2. Do Y"
 }
 
@@ -173,9 +173,9 @@ async fn test_final_channel() {
     let input = r#"<|channel|>commentary to=functions.test<|constrain|>json<|message|>{"x": 1}<|call|>
 <|channel|>final<|message|>The result is calculated.<|return|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "test");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "test");
     // TODO: Verify normal text = "The result is calculated."
 }
 
@@ -187,8 +187,8 @@ async fn test_mixed_commentary_and_calls() {
 <|channel|>commentary to=functions.calc<|constrain|>json<|message|>{"x": 5}<|call|>
 <|channel|>commentary<|message|>Processing...<|end|>"#;
 
-    let result = parser.parse_complete(input).await.unwrap();
-    assert_eq!(result.len(), 1);
-    assert_eq!(result[0].function.name, "calc");
+    let (_normal_text, tools) = parser.parse_complete(input).await.unwrap();
+    assert_eq!(tools.len(), 1);
+    assert_eq!(tools[0].function.name, "calc");
     // TODO: Verify normal text = "Let me think Processing..."
 }