[Router] Add validation module for API parameters (#9335)

sgl-router/src/protocols/common.rs

@@ -26,6 +26,31 @@ pub enum StringOrArray {
     String(String),
     Array(Vec<String>),
 }
+impl StringOrArray {
+    /// Get the number of items in the StringOrArray
+    pub fn len(&self) -> usize {
+        match self {
+            StringOrArray::String(_) => 1,
+            StringOrArray::Array(arr) => arr.len(),
+        }
+    }
+
+    /// Check if the StringOrArray is empty
+    pub fn is_empty(&self) -> bool {
+        match self {
+            StringOrArray::String(s) => s.is_empty(),
+            StringOrArray::Array(arr) => arr.is_empty(),
+        }
+    }
+
+    /// Convert to a vector of strings
+    pub fn to_vec(&self) -> Vec<String> {
+        match self {
+            StringOrArray::String(s) => vec![s.clone()],
+            StringOrArray::Array(arr) => arr.clone(),
+        }
+    }
+}
 
 /// LoRA adapter path - can be single path or batch of paths (SGLang extension)
 #[derive(Debug, Clone, Deserialize, Serialize)]

sgl-router/src/protocols/mod.rs

@@ -4,3 +4,4 @@
 pub mod common;
 pub mod generate;
 pub mod openai;
+pub mod validation;

sgl-router/src/protocols/openai/chat/mod.rs

@@ -3,6 +3,7 @@
 pub mod request;
 pub mod response;
 pub mod types;
+pub mod validation;
 
 // Re-export main types for convenience
 pub use request::ChatCompletionRequest;

sgl-router/src/protocols/openai/chat/validation.rs

@@ -0,0 +1,477 @@
+// Validation implementation for Chat Completions API
+
+use crate::protocols::common::StringOrArray;
+use crate::protocols::openai::chat::request::ChatCompletionRequest;
+use crate::protocols::openai::chat::types::{ChatMessage, ResponseFormat, UserMessageContent};
+use crate::protocols::validation::{
+    utils::{
+        validate_common_request_params, validate_conflicting_parameters,
+        validate_mutually_exclusive_options, validate_non_empty_array,
+    },
+    CompletionCountProvider, LogProbsProvider, SGLangExtensionsProvider, SamplingOptionsProvider,
+    StopConditionsProvider, TokenLimitsProvider, ValidatableRequest, ValidationError,
+};
+
+impl SamplingOptionsProvider for ChatCompletionRequest {
+    fn get_temperature(&self) -> Option<f32> {
+        self.temperature
+    }
+    fn get_top_p(&self) -> Option<f32> {
+        self.top_p
+    }
+    fn get_frequency_penalty(&self) -> Option<f32> {
+        self.frequency_penalty
+    }
+    fn get_presence_penalty(&self) -> Option<f32> {
+        self.presence_penalty
+    }
+}
+
+impl StopConditionsProvider for ChatCompletionRequest {
+    fn get_stop_sequences(&self) -> Option<&StringOrArray> {
+        self.stop.as_ref()
+    }
+}
+
+impl TokenLimitsProvider for ChatCompletionRequest {
+    fn get_max_tokens(&self) -> Option<u32> {
+        // Prefer max_completion_tokens over max_tokens if both are set
+        self.max_completion_tokens.or(self.max_tokens)
+    }
+
+    fn get_min_tokens(&self) -> Option<u32> {
+        self.min_tokens
+    }
+}
+
+impl LogProbsProvider for ChatCompletionRequest {
+    fn get_logprobs(&self) -> Option<u32> {
+        // For chat API, logprobs is a boolean, return 1 if true for validation purposes
+        if self.logprobs {
+            Some(1)
+        } else {
+            None
+        }
+    }
+
+    fn get_top_logprobs(&self) -> Option<u32> {
+        self.top_logprobs
+    }
+}
+
+impl SGLangExtensionsProvider for ChatCompletionRequest {
+    fn get_top_k(&self) -> Option<i32> {
+        self.top_k
+    }
+
+    fn get_min_p(&self) -> Option<f32> {
+        self.min_p
+    }
+
+    fn get_repetition_penalty(&self) -> Option<f32> {
+        self.repetition_penalty
+    }
+}
+
+impl CompletionCountProvider for ChatCompletionRequest {
+    fn get_n(&self) -> Option<u32> {
+        self.n
+    }
+}
+
+impl ChatCompletionRequest {
+    /// Validate message-specific requirements
+    pub fn validate_messages(&self) -> Result<(), ValidationError> {
+        // Ensure messages array is not empty
+        validate_non_empty_array(&self.messages, "messages")?;
+
+        // Validate message content is not empty
+        for (i, msg) in self.messages.iter().enumerate() {
+            if let ChatMessage::User { content, .. } = msg {
+                match content {
+                    UserMessageContent::Text(text) if text.is_empty() => {
+                        return Err(ValidationError::InvalidValue {
+                            parameter: format!("messages[{}].content", i),
+                            value: "empty".to_string(),
+                            reason: "message content cannot be empty".to_string(),
+                        });
+                    }
+                    UserMessageContent::Parts(parts) if parts.is_empty() => {
+                        return Err(ValidationError::InvalidValue {
+                            parameter: format!("messages[{}].content", i),
+                            value: "empty array".to_string(),
+                            reason: "message content parts cannot be empty".to_string(),
+                        });
+                    }
+                    _ => {}
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Validate response format if specified
+    pub fn validate_response_format(&self) -> Result<(), ValidationError> {
+        if let Some(ResponseFormat::JsonSchema { json_schema }) = &self.response_format {
+            if json_schema.name.is_empty() {
+                return Err(ValidationError::InvalidValue {
+                    parameter: "response_format.json_schema.name".to_string(),
+                    value: "empty".to_string(),
+                    reason: "JSON schema name cannot be empty".to_string(),
+                });
+            }
+        }
+        Ok(())
+    }
+
+    /// Validate chat API specific logprobs requirements
+    pub fn validate_chat_logprobs(&self) -> Result<(), ValidationError> {
+        // In chat API, if logprobs=true, top_logprobs must be specified
+        if self.logprobs && self.top_logprobs.is_none() {
+            return Err(ValidationError::MissingRequired {
+                parameter: "top_logprobs".to_string(),
+            });
+        }
+
+        // If top_logprobs is specified, logprobs should be true
+        if self.top_logprobs.is_some() && !self.logprobs {
+            return Err(ValidationError::InvalidValue {
+                parameter: "logprobs".to_string(),
+                value: "false".to_string(),
+                reason: "must be true when top_logprobs is specified".to_string(),
+            });
+        }
+
+        Ok(())
+    }
+
+    /// Validate cross-parameter relationships specific to chat completions
+    pub fn validate_chat_cross_parameters(&self) -> Result<(), ValidationError> {
+        // Validate that both max_tokens and max_completion_tokens aren't set
+        validate_conflicting_parameters(
+            "max_tokens",
+            self.max_tokens.is_some(),
+            "max_completion_tokens",
+            self.max_completion_tokens.is_some(),
+            "cannot specify both max_tokens and max_completion_tokens",
+        )?;
+
+        // Validate that tools and functions aren't both specified (deprecated)
+        validate_conflicting_parameters(
+            "tools",
+            self.tools.is_some(),
+            "functions",
+            self.functions.is_some(),
+            "functions is deprecated, use tools instead",
+        )?;
+
+        // Validate structured output constraints don't conflict with JSON response format
+        let has_json_format = matches!(
+            self.response_format,
+            Some(ResponseFormat::JsonObject | ResponseFormat::JsonSchema { .. })
+        );
+
+        validate_conflicting_parameters(
+            "response_format",
+            has_json_format,
+            "regex",
+            self.regex.is_some(),
+            "cannot use regex constraint with JSON response format",
+        )?;
+
+        validate_conflicting_parameters(
+            "response_format",
+            has_json_format,
+            "ebnf",
+            self.ebnf.is_some(),
+            "cannot use EBNF constraint with JSON response format",
+        )?;
+
+        // Only one structured output constraint should be active
+        let structured_constraints = [
+            ("regex", self.regex.is_some()),
+            ("ebnf", self.ebnf.is_some()),
+            (
+                "json_schema",
+                matches!(
+                    self.response_format,
+                    Some(ResponseFormat::JsonSchema { .. })
+                ),
+            ),
+        ];
+
+        validate_mutually_exclusive_options(
+            &structured_constraints,
+            "Only one structured output constraint (regex, ebnf, or json_schema) can be active at a time",
+        )?;
+
+        Ok(())
+    }
+}
+
+impl ValidatableRequest for ChatCompletionRequest {
+    fn validate(&self) -> Result<(), ValidationError> {
+        // Call the common validation function from the validation module
+        validate_common_request_params(self)?;
+
+        // Then validate chat-specific parameters
+        self.validate_messages()?;
+        self.validate_response_format()?;
+        self.validate_chat_logprobs()?;
+        self.validate_chat_cross_parameters()?;
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::protocols::openai::chat::types::*;
+
+    fn create_valid_request() -> ChatCompletionRequest {
+        ChatCompletionRequest {
+            model: "gpt-4".to_string(),
+            messages: vec![ChatMessage::User {
+                role: "user".to_string(),
+                content: UserMessageContent::Text("Hello".to_string()),
+                name: None,
+            }],
+            temperature: Some(1.0),
+            top_p: Some(0.9),
+            n: Some(1),
+            stream: false,
+            stream_options: None,
+            stop: None,
+            max_tokens: Some(100),
+            max_completion_tokens: None,
+            presence_penalty: Some(0.0),
+            frequency_penalty: Some(0.0),
+            logit_bias: None,
+            user: None,
+            seed: None,
+            logprobs: false,
+            top_logprobs: None,
+            response_format: None,
+            tools: None,
+            tool_choice: None,
+            parallel_tool_calls: None,
+            functions: None,
+            function_call: None,
+            // SGLang extensions
+            top_k: None,
+            min_p: None,
+            min_tokens: None,
+            repetition_penalty: None,
+            regex: None,
+            ebnf: None,
+            stop_token_ids: None,
+            no_stop_trim: false,
+            ignore_eos: false,
+            continue_final_message: false,
+            skip_special_tokens: true,
+            lora_path: None,
+            session_params: None,
+            separate_reasoning: true,
+            stream_reasoning: true,
+            return_hidden_states: false,
+        }
+    }
+
+    #[test]
+    fn test_valid_chat_request() {
+        let request = create_valid_request();
+        assert!(request.validate().is_ok());
+    }
+
+    #[test]
+    fn test_invalid_temperature() {
+        let mut request = create_valid_request();
+        request.temperature = Some(3.0); // Too high
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::OutOfRange { parameter, .. } => {
+                assert_eq!(parameter, "temperature");
+            }
+            _ => panic!("Expected OutOfRange error"),
+        }
+    }
+
+    #[test]
+    fn test_invalid_top_p() {
+        let mut request = create_valid_request();
+        request.top_p = Some(1.5); // Too high
+
+        assert!(request.validate().is_err());
+    }
+
+    #[test]
+    fn test_too_many_stop_sequences() {
+        let mut request = create_valid_request();
+        request.stop = Some(StringOrArray::Array(vec![
+            "stop1".to_string(),
+            "stop2".to_string(),
+            "stop3".to_string(),
+            "stop4".to_string(),
+            "stop5".to_string(), // Too many
+        ]));
+
+        let result = request.validate();
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_empty_stop_sequence() {
+        let mut request = create_valid_request();
+        request.stop = Some(StringOrArray::String("".to_string()));
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::InvalidValue {
+                parameter, reason, ..
+            } => {
+                assert_eq!(parameter, "stop");
+                assert!(reason.contains("empty"));
+            }
+            _ => panic!("Expected InvalidValue error"),
+        }
+    }
+
+    #[test]
+    fn test_empty_messages() {
+        let mut request = create_valid_request();
+        request.messages = vec![];
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::MissingRequired { parameter } => {
+                assert_eq!(parameter, "messages");
+            }
+            _ => panic!("Expected MissingRequired error"),
+        }
+    }
+
+    #[test]
+    fn test_invalid_n_parameter() {
+        let mut request = create_valid_request();
+        request.n = Some(0);
+
+        let result = request.validate();
+        assert!(result.is_err());
+
+        request.n = Some(20); // Too high
+        assert!(request.validate().is_err());
+    }
+
+    #[test]
+    fn test_conflicting_max_tokens() {
+        let mut request = create_valid_request();
+        request.max_tokens = Some(100);
+        request.max_completion_tokens = Some(200);
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::ConflictingParameters {
+                parameter1,
+                parameter2,
+                ..
+            } => {
+                assert!(parameter1.contains("max_tokens"));
+                assert!(parameter2.contains("max_completion_tokens"));
+            }
+            _ => panic!("Expected ConflictingParameters error"),
+        }
+    }
+
+    #[test]
+    fn test_logprobs_without_top_logprobs() {
+        let mut request = create_valid_request();
+        request.logprobs = true;
+        request.top_logprobs = None;
+
+        let result = request.validate();
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_sglang_extensions() {
+        let mut request = create_valid_request();
+
+        // Valid top_k
+        request.top_k = Some(-1); // Disabled
+        assert!(request.validate().is_ok());
+
+        request.top_k = Some(50); // Valid positive
+        assert!(request.validate().is_ok());
+
+        request.top_k = Some(0); // Invalid
+        assert!(request.validate().is_err());
+
+        // Valid min_p
+        request.top_k = None;
+        request.min_p = Some(0.1);
+        assert!(request.validate().is_ok());
+
+        request.min_p = Some(1.5); // Too high
+        assert!(request.validate().is_err());
+
+        // Valid repetition_penalty
+        request.min_p = None;
+        request.repetition_penalty = Some(1.2);
+        assert!(request.validate().is_ok());
+
+        request.repetition_penalty = Some(0.0); // Valid - minimum value
+        assert!(request.validate().is_ok());
+
+        request.repetition_penalty = Some(2.0); // Valid - maximum value
+        assert!(request.validate().is_ok());
+
+        request.repetition_penalty = Some(2.1); // Invalid - too high
+        assert!(request.validate().is_err());
+
+        request.repetition_penalty = Some(-0.1); // Invalid - negative
+        assert!(request.validate().is_err());
+    }
+
+    #[test]
+    fn test_structured_output_conflicts() {
+        let mut request = create_valid_request();
+
+        // JSON response format with regex should conflict
+        request.response_format = Some(ResponseFormat::JsonObject);
+        request.regex = Some(".*".to_string());
+
+        let result = request.validate();
+        assert!(result.is_err());
+
+        // Multiple structured constraints should conflict
+        request.response_format = None;
+        request.regex = Some(".*".to_string());
+        request.ebnf = Some("grammar".to_string());
+
+        let result = request.validate();
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_min_max_tokens_validation() {
+        let mut request = create_valid_request();
+        request.min_tokens = Some(100);
+        request.max_tokens = Some(50); // min > max
+
+        let result = request.validate();
+        assert!(result.is_err());
+
+        // Should work with max_completion_tokens too
+        request.max_tokens = None;
+        request.max_completion_tokens = Some(200);
+        request.min_tokens = Some(100);
+        assert!(request.validate().is_ok());
+    }
+}

sgl-router/src/protocols/validation.rs

@@ -0,0 +1,757 @@
+// Core validation infrastructure for API parameter validation
+
+use anyhow::Result;
+use serde::{Deserialize, Serialize};
+use std::fmt::Display;
+
+/// Validation constants for OpenAI API parameters
+pub mod constants {
+    /// Temperature range: 0.0 to 2.0 (OpenAI spec)
+    pub const TEMPERATURE_RANGE: (f32, f32) = (0.0, 2.0);
+
+    /// Top-p range: 0.0 to 1.0 (exclusive of 0.0)
+    pub const TOP_P_RANGE: (f32, f32) = (0.0, 1.0);
+
+    /// Presence penalty range: -2.0 to 2.0 (OpenAI spec)
+    pub const PRESENCE_PENALTY_RANGE: (f32, f32) = (-2.0, 2.0);
+
+    /// Frequency penalty range: -2.0 to 2.0 (OpenAI spec)
+    pub const FREQUENCY_PENALTY_RANGE: (f32, f32) = (-2.0, 2.0);
+
+    /// Logprobs range for completions API: 0 to 5
+    pub const LOGPROBS_RANGE: (u32, u32) = (0, 5);
+
+    /// Top logprobs range for chat completions: 0 to 20
+    pub const TOP_LOGPROBS_RANGE: (u32, u32) = (0, 20);
+
+    /// Maximum number of stop sequences allowed
+    pub const MAX_STOP_SEQUENCES: usize = 4;
+
+    /// SGLang-specific validation constants
+    pub mod sglang {
+        /// Min-p range: 0.0 to 1.0 (SGLang extension)
+        pub const MIN_P_RANGE: (f32, f32) = (0.0, 1.0);
+
+        /// Top-k minimum value: -1 to disable, otherwise positive
+        pub const TOP_K_MIN: i32 = -1;
+
+        /// Repetition penalty range: 0.0 to 2.0 (SGLang extension)
+        /// 1.0 = no penalty, >1.0 = discourage repetition, <1.0 = encourage repetition
+        pub const REPETITION_PENALTY_RANGE: (f32, f32) = (0.0, 2.0);
+    }
+}
+
+/// Core validation error types
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum ValidationError {
+    /// Parameter value out of valid range
+    OutOfRange {
+        parameter: String,
+        value: String,
+        min: String,
+        max: String,
+    },
+    /// Invalid parameter value format or type
+    InvalidValue {
+        parameter: String,
+        value: String,
+        reason: String,
+    },
+    /// Cross-parameter validation failure
+    ConflictingParameters {
+        parameter1: String,
+        parameter2: String,
+        reason: String,
+    },
+    /// Required parameter missing
+    MissingRequired { parameter: String },
+    /// Too many items in array parameter
+    TooManyItems {
+        parameter: String,
+        count: usize,
+        max: usize,
+    },
+    /// Custom validation error
+    Custom(String),
+}
+
+impl Display for ValidationError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ValidationError::OutOfRange {
+                parameter,
+                value,
+                min,
+                max,
+            } => {
+                write!(
+                    f,
+                    "Parameter '{}' must be between {} and {}, got {}",
+                    parameter, min, max, value
+                )
+            }
+            ValidationError::InvalidValue {
+                parameter,
+                value,
+                reason,
+            } => {
+                write!(
+                    f,
+                    "Invalid value for parameter '{}': {} ({})",
+                    parameter, value, reason
+                )
+            }
+            ValidationError::ConflictingParameters {
+                parameter1,
+                parameter2,
+                reason,
+            } => {
+                write!(
+                    f,
+                    "Conflicting parameters '{}' and '{}': {}",
+                    parameter1, parameter2, reason
+                )
+            }
+            ValidationError::MissingRequired { parameter } => {
+                write!(f, "Required parameter '{}' is missing", parameter)
+            }
+            ValidationError::TooManyItems {
+                parameter,
+                count,
+                max,
+            } => {
+                write!(
+                    f,
+                    "Parameter '{}' has too many items: {} (maximum: {})",
+                    parameter, count, max
+                )
+            }
+            ValidationError::Custom(msg) => write!(f, "{}", msg),
+        }
+    }
+}
+
+impl std::error::Error for ValidationError {}
+
+/// Core validation utility functions
+pub mod utils {
+    use super::*;
+
+    /// Validate that a numeric value is within the specified range (inclusive)
+    pub fn validate_range<T>(
+        value: T,
+        range: &(T, T),
+        param_name: &str,
+    ) -> Result<T, ValidationError>
+    where
+        T: PartialOrd + Display + Copy,
+    {
+        if value >= range.0 && value <= range.1 {
+            Ok(value)
+        } else {
+            Err(ValidationError::OutOfRange {
+                parameter: param_name.to_string(),
+                value: value.to_string(),
+                min: range.0.to_string(),
+                max: range.1.to_string(),
+            })
+        }
+    }
+
+    /// Validate that a positive number is actually positive
+    pub fn validate_positive<T>(value: T, param_name: &str) -> Result<T, ValidationError>
+    where
+        T: PartialOrd + Display + Copy + Default,
+    {
+        if value > T::default() {
+            Ok(value)
+        } else {
+            Err(ValidationError::InvalidValue {
+                parameter: param_name.to_string(),
+                value: value.to_string(),
+                reason: "must be positive".to_string(),
+            })
+        }
+    }
+
+    /// Validate that an array doesn't exceed maximum length
+    pub fn validate_max_items<T>(
+        items: &[T],
+        max_count: usize,
+        param_name: &str,
+    ) -> Result<(), ValidationError> {
+        if items.len() <= max_count {
+            Ok(())
+        } else {
+            Err(ValidationError::TooManyItems {
+                parameter: param_name.to_string(),
+                count: items.len(),
+                max: max_count,
+            })
+        }
+    }
+
+    /// Validate that a required parameter is present
+    pub fn validate_required<'a, T>(
+        value: &'a Option<T>,
+        param_name: &str,
+    ) -> Result<&'a T, ValidationError> {
+        value
+            .as_ref()
+            .ok_or_else(|| ValidationError::MissingRequired {
+                parameter: param_name.to_string(),
+            })
+    }
+
+    /// Validate top_k parameter (SGLang extension)
+    pub fn validate_top_k(top_k: i32) -> Result<i32, ValidationError> {
+        if top_k == constants::sglang::TOP_K_MIN || top_k > 0 {
+            Ok(top_k)
+        } else {
+            Err(ValidationError::InvalidValue {
+                parameter: "top_k".to_string(),
+                value: top_k.to_string(),
+                reason: "must be -1 (disabled) or positive".to_string(),
+            })
+        }
+    }
+
+    /// Generic validation function for sampling options
+    pub fn validate_sampling_options<T: SamplingOptionsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        // Validate temperature (0.0 to 2.0)
+        if let Some(temp) = request.get_temperature() {
+            validate_range(temp, &constants::TEMPERATURE_RANGE, "temperature")?;
+        }
+
+        // Validate top_p (0.0 to 1.0)
+        if let Some(top_p) = request.get_top_p() {
+            validate_range(top_p, &constants::TOP_P_RANGE, "top_p")?;
+        }
+
+        // Validate frequency_penalty (-2.0 to 2.0)
+        if let Some(freq_penalty) = request.get_frequency_penalty() {
+            validate_range(
+                freq_penalty,
+                &constants::FREQUENCY_PENALTY_RANGE,
+                "frequency_penalty",
+            )?;
+        }
+
+        // Validate presence_penalty (-2.0 to 2.0)
+        if let Some(pres_penalty) = request.get_presence_penalty() {
+            validate_range(
+                pres_penalty,
+                &constants::PRESENCE_PENALTY_RANGE,
+                "presence_penalty",
+            )?;
+        }
+
+        Ok(())
+    }
+
+    /// Generic validation function for stop conditions
+    pub fn validate_stop_conditions<T: StopConditionsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        if let Some(stop) = request.get_stop_sequences() {
+            match stop {
+                crate::protocols::common::StringOrArray::String(s) => {
+                    if s.is_empty() {
+                        return Err(ValidationError::InvalidValue {
+                            parameter: "stop".to_string(),
+                            value: "empty string".to_string(),
+                            reason: "stop sequences cannot be empty".to_string(),
+                        });
+                    }
+                }
+                crate::protocols::common::StringOrArray::Array(arr) => {
+                    validate_max_items(arr, constants::MAX_STOP_SEQUENCES, "stop")?;
+                    for (i, s) in arr.iter().enumerate() {
+                        if s.is_empty() {
+                            return Err(ValidationError::InvalidValue {
+                                parameter: format!("stop[{}]", i),
+                                value: "empty string".to_string(),
+                                reason: "stop sequences cannot be empty".to_string(),
+                            });
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Generic validation function for token limits
+    pub fn validate_token_limits<T: TokenLimitsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        // Validate max_tokens if provided
+        if let Some(max_tokens) = request.get_max_tokens() {
+            validate_positive(max_tokens, "max_tokens")?;
+        }
+
+        // Validate min_tokens if provided (SGLang extension)
+        if let Some(min_tokens) = request.get_min_tokens() {
+            validate_positive(min_tokens, "min_tokens")?;
+        }
+
+        Ok(())
+    }
+
+    /// Generic validation function for logprobs
+    pub fn validate_logprobs<T: LogProbsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        // Validate logprobs (completions API - 0 to 5)
+        if let Some(logprobs) = request.get_logprobs() {
+            validate_range(logprobs, &constants::LOGPROBS_RANGE, "logprobs")?;
+        }
+
+        // Validate top_logprobs (chat API - 0 to 20)
+        if let Some(top_logprobs) = request.get_top_logprobs() {
+            validate_range(top_logprobs, &constants::TOP_LOGPROBS_RANGE, "top_logprobs")?;
+        }
+
+        Ok(())
+    }
+
+    /// Generic cross-parameter validation
+    pub fn validate_cross_parameters<T: TokenLimitsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        // Check min_tokens <= max_tokens if both are specified
+        if let (Some(min_tokens), Some(max_tokens)) =
+            (request.get_min_tokens(), request.get_max_tokens())
+        {
+            if min_tokens > max_tokens {
+                return Err(ValidationError::ConflictingParameters {
+                    parameter1: "min_tokens".to_string(),
+                    parameter2: "max_tokens".to_string(),
+                    reason: format!(
+                        "min_tokens ({}) cannot be greater than max_tokens ({})",
+                        min_tokens, max_tokens
+                    ),
+                });
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Validate conflicting structured output constraints
+    pub fn validate_conflicting_parameters(
+        param1_name: &str,
+        param1_value: bool,
+        param2_name: &str,
+        param2_value: bool,
+        reason: &str,
+    ) -> Result<(), ValidationError> {
+        if param1_value && param2_value {
+            return Err(ValidationError::ConflictingParameters {
+                parameter1: param1_name.to_string(),
+                parameter2: param2_name.to_string(),
+                reason: reason.to_string(),
+            });
+        }
+        Ok(())
+    }
+
+    /// Validate that only one option from a set is active
+    pub fn validate_mutually_exclusive_options(
+        options: &[(&str, bool)],
+        error_msg: &str,
+    ) -> Result<(), ValidationError> {
+        let active_count = options.iter().filter(|(_, is_active)| *is_active).count();
+        if active_count > 1 {
+            return Err(ValidationError::Custom(error_msg.to_string()));
+        }
+        Ok(())
+    }
+
+    /// Generic validation for SGLang extensions
+    pub fn validate_sglang_extensions<T: SGLangExtensionsProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        // Validate top_k (-1 to disable, or positive)
+        if let Some(top_k) = request.get_top_k() {
+            validate_top_k(top_k)?;
+        }
+
+        // Validate min_p (0.0 to 1.0)
+        if let Some(min_p) = request.get_min_p() {
+            validate_range(min_p, &constants::sglang::MIN_P_RANGE, "min_p")?;
+        }
+
+        // Validate repetition_penalty (0.0 to 2.0)
+        if let Some(rep_penalty) = request.get_repetition_penalty() {
+            validate_range(
+                rep_penalty,
+                &constants::sglang::REPETITION_PENALTY_RANGE,
+                "repetition_penalty",
+            )?;
+        }
+
+        Ok(())
+    }
+
+    /// Generic validation for n parameter (number of completions)
+    pub fn validate_completion_count<T: CompletionCountProvider + ?Sized>(
+        request: &T,
+    ) -> Result<(), ValidationError> {
+        const N_RANGE: (u32, u32) = (1, 10);
+
+        if let Some(n) = request.get_n() {
+            validate_range(n, &N_RANGE, "n")?;
+        }
+
+        Ok(())
+    }
+
+    /// Validate that an array is not empty
+    pub fn validate_non_empty_array<T>(
+        items: &[T],
+        param_name: &str,
+    ) -> Result<(), ValidationError> {
+        if items.is_empty() {
+            return Err(ValidationError::MissingRequired {
+                parameter: param_name.to_string(),
+            });
+        }
+        Ok(())
+    }
+
+    /// Validate common request parameters that are shared across all API types
+    pub fn validate_common_request_params<T>(request: &T) -> Result<(), ValidationError>
+    where
+        T: SamplingOptionsProvider
+            + StopConditionsProvider
+            + TokenLimitsProvider
+            + LogProbsProvider
+            + SGLangExtensionsProvider
+            + CompletionCountProvider
+            + ?Sized,
+    {
+        // Validate all standard parameters
+        validate_sampling_options(request)?;
+        validate_stop_conditions(request)?;
+        validate_token_limits(request)?;
+        validate_logprobs(request)?;
+
+        // Validate SGLang extensions and completion count
+        validate_sglang_extensions(request)?;
+        validate_completion_count(request)?;
+
+        // Perform cross-parameter validation
+        validate_cross_parameters(request)?;
+
+        Ok(())
+    }
+}
+
+/// Core validation traits for different parameter categories
+pub trait SamplingOptionsProvider {
+    /// Get temperature parameter
+    fn get_temperature(&self) -> Option<f32>;
+
+    /// Get top_p parameter
+    fn get_top_p(&self) -> Option<f32>;
+
+    /// Get frequency penalty parameter
+    fn get_frequency_penalty(&self) -> Option<f32>;
+
+    /// Get presence penalty parameter
+    fn get_presence_penalty(&self) -> Option<f32>;
+}
+
+/// Trait for validating stop conditions
+pub trait StopConditionsProvider {
+    /// Get stop sequences
+    fn get_stop_sequences(&self) -> Option<&crate::protocols::common::StringOrArray>;
+}
+
+/// Trait for validating token limits
+pub trait TokenLimitsProvider {
+    /// Get maximum tokens parameter
+    fn get_max_tokens(&self) -> Option<u32>;
+
+    /// Get minimum tokens parameter (SGLang extension)
+    fn get_min_tokens(&self) -> Option<u32>;
+}
+
+/// Trait for validating logprobs parameters
+pub trait LogProbsProvider {
+    /// Get logprobs parameter (completions API)
+    fn get_logprobs(&self) -> Option<u32>;
+
+    /// Get top_logprobs parameter (chat API)
+    fn get_top_logprobs(&self) -> Option<u32>;
+}
+
+/// Trait for SGLang-specific extensions
+pub trait SGLangExtensionsProvider {
+    /// Get top_k parameter
+    fn get_top_k(&self) -> Option<i32> {
+        None
+    }
+
+    /// Get min_p parameter
+    fn get_min_p(&self) -> Option<f32> {
+        None
+    }
+
+    /// Get repetition_penalty parameter
+    fn get_repetition_penalty(&self) -> Option<f32> {
+        None
+    }
+}
+
+/// Trait for n parameter (number of completions)
+pub trait CompletionCountProvider {
+    /// Get n parameter
+    fn get_n(&self) -> Option<u32> {
+        None
+    }
+}
+
+/// Comprehensive validation trait that combines all validation aspects
+pub trait ValidatableRequest:
+    SamplingOptionsProvider
+    + StopConditionsProvider
+    + TokenLimitsProvider
+    + LogProbsProvider
+    + SGLangExtensionsProvider
+    + CompletionCountProvider
+{
+    /// Perform comprehensive validation of the entire request
+    fn validate(&self) -> Result<(), ValidationError> {
+        // Use the common validation function
+        utils::validate_common_request_params(self)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::constants::*;
+    use super::utils::*;
+    use super::*;
+    use crate::protocols::common::StringOrArray;
+
+    // Mock request type for testing validation traits
+    #[derive(Debug, Default)]
+    struct MockRequest {
+        temperature: Option<f32>,
+        top_p: Option<f32>,
+        frequency_penalty: Option<f32>,
+        presence_penalty: Option<f32>,
+        stop: Option<StringOrArray>,
+        max_tokens: Option<u32>,
+        min_tokens: Option<u32>,
+        logprobs: Option<u32>,
+        top_logprobs: Option<u32>,
+    }
+
+    impl SamplingOptionsProvider for MockRequest {
+        fn get_temperature(&self) -> Option<f32> {
+            self.temperature
+        }
+        fn get_top_p(&self) -> Option<f32> {
+            self.top_p
+        }
+        fn get_frequency_penalty(&self) -> Option<f32> {
+            self.frequency_penalty
+        }
+        fn get_presence_penalty(&self) -> Option<f32> {
+            self.presence_penalty
+        }
+    }
+
+    impl StopConditionsProvider for MockRequest {
+        fn get_stop_sequences(&self) -> Option<&StringOrArray> {
+            self.stop.as_ref()
+        }
+    }
+
+    impl TokenLimitsProvider for MockRequest {
+        fn get_max_tokens(&self) -> Option<u32> {
+            self.max_tokens
+        }
+        fn get_min_tokens(&self) -> Option<u32> {
+            self.min_tokens
+        }
+    }
+
+    impl LogProbsProvider for MockRequest {
+        fn get_logprobs(&self) -> Option<u32> {
+            self.logprobs
+        }
+        fn get_top_logprobs(&self) -> Option<u32> {
+            self.top_logprobs
+        }
+    }
+
+    impl SGLangExtensionsProvider for MockRequest {
+        // Default implementations return None, so no custom logic needed
+    }
+
+    impl CompletionCountProvider for MockRequest {
+        // Default implementation returns None, so no custom logic needed
+    }
+
+    impl ValidatableRequest for MockRequest {}
+
+    #[test]
+    fn test_validate_range_valid() {
+        let result = validate_range(1.5f32, &TEMPERATURE_RANGE, "temperature");
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), 1.5f32);
+    }
+
+    #[test]
+    fn test_validate_range_too_low() {
+        let result = validate_range(-0.1f32, &TEMPERATURE_RANGE, "temperature");
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::OutOfRange { parameter, .. } => {
+                assert_eq!(parameter, "temperature");
+            }
+            _ => panic!("Expected OutOfRange error"),
+        }
+    }
+
+    #[test]
+    fn test_validate_positive_valid() {
+        let result = validate_positive(5i32, "max_tokens");
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), 5i32);
+    }
+
+    #[test]
+    fn test_validate_max_items_valid() {
+        let items = vec!["stop1", "stop2"];
+        let result = validate_max_items(&items, MAX_STOP_SEQUENCES, "stop");
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_validate_top_k() {
+        assert!(validate_top_k(-1).is_ok()); // Disabled
+        assert!(validate_top_k(50).is_ok()); // Positive
+        assert!(validate_top_k(0).is_err()); // Invalid
+        assert!(validate_top_k(-5).is_err()); // Invalid
+    }
+
+    #[test]
+    fn test_valid_request() {
+        let request = MockRequest {
+            temperature: Some(1.0),
+            top_p: Some(0.9),
+            frequency_penalty: Some(0.5),
+            presence_penalty: Some(-0.5),
+            stop: Some(StringOrArray::Array(vec![
+                "stop1".to_string(),
+                "stop2".to_string(),
+            ])),
+            max_tokens: Some(100),
+            min_tokens: Some(10),
+            logprobs: Some(3),
+            top_logprobs: Some(15),
+        };
+
+        assert!(request.validate().is_ok());
+    }
+
+    #[test]
+    fn test_invalid_temperature() {
+        let request = MockRequest {
+            temperature: Some(3.0), // Invalid: too high
+            ..Default::default()
+        };
+
+        let result = request.validate();
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_too_many_stop_sequences() {
+        let request = MockRequest {
+            stop: Some(StringOrArray::Array(vec![
+                "stop1".to_string(),
+                "stop2".to_string(),
+                "stop3".to_string(),
+                "stop4".to_string(),
+                "stop5".to_string(), // Too many
+            ])),
+            ..Default::default()
+        };
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::TooManyItems {
+                parameter,
+                count,
+                max,
+            } => {
+                assert_eq!(parameter, "stop");
+                assert_eq!(count, 5);
+                assert_eq!(max, MAX_STOP_SEQUENCES);
+            }
+            _ => panic!("Expected TooManyItems error"),
+        }
+    }
+
+    #[test]
+    fn test_conflicting_token_limits() {
+        let request = MockRequest {
+            min_tokens: Some(100),
+            max_tokens: Some(50), // Invalid: min > max
+            ..Default::default()
+        };
+
+        let result = request.validate();
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ValidationError::ConflictingParameters {
+                parameter1,
+                parameter2,
+                ..
+            } => {
+                assert_eq!(parameter1, "min_tokens");
+                assert_eq!(parameter2, "max_tokens");
+            }
+            _ => panic!("Expected ConflictingParameters error"),
+        }
+    }
+
+    #[test]
+    fn test_boundary_values() {
+        let request = MockRequest {
+            temperature: Some(0.0),        // Boundary: minimum
+            top_p: Some(1.0),              // Boundary: maximum
+            frequency_penalty: Some(-2.0), // Boundary: minimum
+            presence_penalty: Some(2.0),   // Boundary: maximum
+            logprobs: Some(0),             // Boundary: minimum
+            top_logprobs: Some(20),        // Boundary: maximum
+            ..Default::default()
+        };
+
+        assert!(request.validate().is_ok());
+    }
+
+    #[test]
+    fn test_validation_error_display() {
+        let error = ValidationError::OutOfRange {
+            parameter: "temperature".to_string(),
+            value: "3.0".to_string(),
+            min: "0.0".to_string(),
+            max: "2.0".to_string(),
+        };
+
+        let message = format!("{}", error);
+        assert!(message.contains("temperature"));
+        assert!(message.contains("3.0"));
+    }
+}