support parameters_json_schema in function declaration

src/lib.rs

@@ -43,8 +43,12 @@ pub enum GeminiError {
     EventSource(#[from] reqwest_eventsource::Error),
     #[error("API Error: {0}")]
     Api(Value),
-    #[error("JSON Error: {0}")]
-    Json(#[from] serde_json::Error),
+    #[error("JSON Error: {error} (payload: {data})")]
+    Json {
+        data: String,
+        #[source]
+        error: serde_json::Error,
+    },
     #[error("Function execution error: {0}")]
     FunctionExecution(String),
 }
@@ -210,7 +214,10 @@ impl GeminiClient {
                         Event::Open => (),
                         Event::Message(event) => yield
                             serde_json::from_str::<types::GenerateContentResponse>(&event.data)
-                                .map_err(Into::into),
+                                .map_err(|error| GeminiError::Json {
+                                    data: event.data,
+                                    error,
+                                }),
                     },
                     Err(e) => match e {
                         reqwest_eventsource::Error::StreamEnded => stream.close(),

src/types.rs

@@ -99,6 +99,7 @@ pub enum FunctionCallingMode {
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct Content {
+    #[serde(default)]
     pub parts: Vec<ContentPart>,
     // Optional. The producer of the content. Must be either 'user' or 'model'.
     // Useful to set for multi-turn conversations, otherwise can be left blank or unset.
@@ -171,6 +172,7 @@ pub struct FunctionDeclaration {
     pub name: String,
     pub description: String,
     pub parameters: Option<FunctionParameters>,
+    pub parameters_json_schema: Option<serde_json::Value>,
     pub response: Option<FunctionParameters>,
 }
 
@@ -344,6 +346,25 @@ pub struct ThinkingConfig {
     pub include_thoughts: bool,
     /// The number of thoughts tokens that the model should generate.
     pub thinking_budget: Option<u32>,
+    /// Controls the maximum depth of the model's internal reasoning process
+    /// before it produces a response. If not specified, the default is HIGH.
+    /// Recommended for Gemini 3 or later models. Use with earlier models
+    /// results in an error.
+    pub thinking_level: Option<ThinkingLevel>,
+}
+
+/// Allow user to specify how much to think using enum instead of integer
+/// budget.
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, Default, PartialEq)]
+#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
+pub enum ThinkingLevel {
+    /// Unspecified thinking level.
+    #[default]
+    ThinkingLevelUnspecified,
+    /// High thinking level.
+    High,
+    /// Low thinking level.
+    Low,
 }
 
 /// A response candidate generated from the model.