feat(image): add image generation tool support

.gitignore

@@ -160,3 +160,6 @@ clients/java/target/
 clients/java/build.sbt
 clients/java/gradle.properties
 openapitools.json
+
+# Local MCP config
+mcp.local.yaml

crates/mcp/src/core/config.rs

@@ -292,6 +292,8 @@ pub enum BuiltinToolType {
     WebSearchPreview,
     /// Code interpreter tool (OpenAI: code_interpreter)
     CodeInterpreter,
+    /// Image generation tool (OpenAI: image_generation)
+    ImageGeneration,
     /// File search tool (OpenAI: file_search)
     FileSearch,
 }
@@ -302,6 +304,7 @@ impl BuiltinToolType {
         match self {
             BuiltinToolType::WebSearchPreview => ResponseFormatConfig::WebSearchCall,
             BuiltinToolType::CodeInterpreter => ResponseFormatConfig::CodeInterpreterCall,
+            BuiltinToolType::ImageGeneration => ResponseFormatConfig::ImageGenerationCall,
             BuiltinToolType::FileSearch => ResponseFormatConfig::FileSearchCall,
         }
     }
@@ -312,6 +315,7 @@ impl fmt::Display for BuiltinToolType {
         match self {
             BuiltinToolType::WebSearchPreview => write!(f, "web_search_preview"),
             BuiltinToolType::CodeInterpreter => write!(f, "code_interpreter"),
+            BuiltinToolType::ImageGeneration => write!(f, "image_generation"),
             BuiltinToolType::FileSearch => write!(f, "file_search"),
         }
     }
@@ -341,6 +345,7 @@ pub enum ResponseFormatConfig {
     Passthrough,
     WebSearchCall,
     CodeInterpreterCall,
+    ImageGenerationCall,
     FileSearchCall,
 }
 
@@ -1016,6 +1021,10 @@ tools:
                 ResponseFormatConfig::CodeInterpreterCall,
                 "\"code_interpreter_call\"",
             ),
+            (
+                ResponseFormatConfig::ImageGenerationCall,
+                "\"image_generation_call\"",
+            ),
             (ResponseFormatConfig::FileSearchCall, "\"file_search_call\""),
         ];
 
@@ -1182,6 +1191,7 @@ policy:
         let types = vec![
             (BuiltinToolType::WebSearchPreview, "\"web_search_preview\""),
             (BuiltinToolType::CodeInterpreter, "\"code_interpreter\""),
+            (BuiltinToolType::ImageGeneration, "\"image_generation\""),
             (BuiltinToolType::FileSearch, "\"file_search\""),
         ];
 
@@ -1204,6 +1214,10 @@ policy:
             BuiltinToolType::CodeInterpreter.response_format(),
             ResponseFormatConfig::CodeInterpreterCall
         );
+        assert_eq!(
+            BuiltinToolType::ImageGeneration.response_format(),
+            ResponseFormatConfig::ImageGenerationCall
+        );
         assert_eq!(
             BuiltinToolType::FileSearch.response_format(),
             ResponseFormatConfig::FileSearchCall
@@ -1475,6 +1489,10 @@ servers:
             BuiltinToolType::CodeInterpreter.to_string(),
             "code_interpreter"
         );
+        assert_eq!(
+            BuiltinToolType::ImageGeneration.to_string(),
+            "image_generation"
+        );
         assert_eq!(BuiltinToolType::FileSearch.to_string(), "file_search");
     }
 }

crates/mcp/src/lib.rs

@@ -56,4 +56,7 @@ pub use responses_bridge::{
 };
 pub use tenant::{SessionId, TenantContext, TenantId};
 // Re-export from transform
-pub use transform::{mcp_response_item_id, ResponseFormat, ResponseTransformer};
+pub use transform::{
+    extract_image_generation_fallback_text, is_image_generation_error, mcp_response_item_id,
+    ResponseFormat, ResponseTransformer,
+};

crates/mcp/src/transform/mod.rs

@@ -22,5 +22,8 @@
 mod transformer;
 mod types;
 
-pub use transformer::{mcp_response_item_id, ResponseTransformer};
+pub use transformer::{
+    extract_image_generation_fallback_text, is_image_generation_error, mcp_response_item_id,
+    ResponseTransformer,
+};
 pub use types::ResponseFormat;