fix(cerebras): preserve thinking inline for models that reject reasoning_content

crates/goose-provider-types/src/base.rs

@@ -2,6 +2,8 @@ use async_trait::async_trait;
 use futures::Stream;
 use rmcp::model::Tool;
 use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::collections::HashMap;
 use std::pin::Pin;
 
 use crate::{
@@ -216,6 +218,21 @@ impl ConfigKey {
     }
 }
 
+/// How a model's thinking is replayed back to the provider on subsequent turns.
+///
+/// Cerebras rejects requests that replay `messages[].reasoning_content`, so such models
+/// declare an inline `content` form instead.
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq)]
+#[serde(rename_all = "snake_case")]
+pub enum ThinkingPreservationFormat {
+    /// Prepend the thinking to the message content as plain text.
+    ContentPrepend,
+    /// Prepend the thinking to the message content wrapped in `<think>` tags.
+    ContentXml,
+    /// Replay in the separate `reasoning_content` field, the OpenAI-compatible default.
+    ReasoningContent,
+}
+
 /// Information about a model's capabilities
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct ModelInfo {
@@ -237,6 +254,11 @@ pub struct ModelInfo {
     /// Whether this model supports reasoning/thinking controls
     #[serde(default)]
     pub reasoning: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub thinking_preservation_format: Option<ThinkingPreservationFormat>,
+    /// Static params merged into the request body for this model.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub request_params: Option<HashMap<String, Value>>,
 }
 
 impl ModelInfo {
@@ -251,6 +273,8 @@ impl ModelInfo {
             currency: None,
             supports_cache_control: None,
             reasoning: false,
+            thinking_preservation_format: None,
+            request_params: None,
         }
     }
 
@@ -270,6 +294,8 @@ impl ModelInfo {
             currency: Some("$".to_string()),
             supports_cache_control: None,
             reasoning: false,
+            thinking_preservation_format: None,
+            request_params: None,
         }
     }
 }
@@ -315,6 +341,8 @@ pub fn model_info_for_provider_model(provider_name: &str, model_name: &str) -> M
         currency: None,
         supports_cache_control: None,
         reasoning,
+        thinking_preservation_format: None,
+        request_params: None,
     }
 }
 
@@ -775,6 +803,8 @@ mod tests {
             currency: None,
             supports_cache_control: None,
             reasoning: false,
+            thinking_preservation_format: None,
+            request_params: None,
         };
         assert_eq!(info.context_limit, 1000);
 
@@ -788,6 +818,8 @@ mod tests {
             currency: None,
             supports_cache_control: None,
             reasoning: false,
+            thinking_preservation_format: None,
+            request_params: None,
         };
         assert_eq!(info, info2);
 
@@ -801,10 +833,39 @@ mod tests {
             currency: None,
             supports_cache_control: None,
             reasoning: false,
+            thinking_preservation_format: None,
+            request_params: None,
         };
         assert_ne!(info, info3);
     }
 
+    #[test]
+    fn test_model_info_deserializes_thinking_preservation_and_request_params() {
+        let info: ModelInfo = serde_json::from_str(
+            r#"{
+                "name": "zai-glm-4.7",
+                "context_limit": 131072,
+                "thinking_preservation_format": "content_xml",
+                "request_params": {"reasoning_format": "parsed"}
+            }"#,
+        )
+        .unwrap();
+
+        assert_eq!(
+            info.thinking_preservation_format,
+            Some(ThinkingPreservationFormat::ContentXml)
+        );
+        assert_eq!(
+            info.request_params.unwrap().get("reasoning_format"),
+            Some(&serde_json::json!("parsed"))
+        );
+
+        let bare: ModelInfo =
+            serde_json::from_str(r#"{"name": "gpt-4o", "context_limit": 128000}"#).unwrap();
+        assert_eq!(bare.thinking_preservation_format, None);
+        assert_eq!(bare.request_params, None);
+    }
+
     #[test]
     fn test_model_info_with_cost() {
         let info = ModelInfo::with_cost("gpt-4o", 128000, 0.0000025, 0.00001);