add error property to tool messages to enable retrying failed frontend tools (#213)

Author: mme

docs/sdk/js/core/types.mdx

@@ -143,6 +143,7 @@ type ToolMessage = {
   content: string
   role: "tool"
   toolCallId: string
+  error?: string
 }
 ```
 
@@ -152,6 +153,7 @@ type ToolMessage = {
 | `content`    | `string` | Text content of the message                  |
 | `role`       | `"tool"` | Role of the message sender, fixed as "tool"  |
 | `toolCallId` | `string` | ID of the tool call this message responds to |
+| `error`      | `string` | Error message if the tool call failed        |
 
 ### Message
 

docs/sdk/python/core/types.mdx

@@ -144,6 +144,7 @@ class ToolMessage(ConfiguredBaseModel):
     role: Literal["tool"]
     content: str
     tool_call_id: str
+    error: Optional[str] = None
 ```
 
 | Property       | Type              | Description                                  |
@@ -152,6 +153,7 @@ class ToolMessage(ConfiguredBaseModel):
 | `content`      | `str`             | Text content of the message                  |
 | `role`         | `Literal["tool"]` | Role of the message sender, fixed as "tool"  |
 | `tool_call_id` | `str`             | ID of the tool call this message responds to |
+| `error`        | `Optional[str]`   | Error message if the tool call failed        |
 
 ### Message
 

python-sdk/ag_ui/core/types.py

@@ -86,6 +86,7 @@ class ToolMessage(ConfiguredBaseModel):
     role: Literal["tool"] = "tool"
     content: str
     tool_call_id: str
+    error: Optional[str] = None
 
 
 Message = Annotated[

typescript-sdk/packages/core/src/types.ts

@@ -44,6 +44,7 @@ export const ToolMessageSchema = z.object({
   content: z.string(),
   role: z.literal("tool"),
   toolCallId: z.string(),
+  error: z.string().optional(),
 });
 
 export const MessageSchema = z.discriminatedUnion("role", [

typescript-sdk/packages/proto/src/proto/types.proto

@@ -19,4 +19,5 @@ message Message {
   optional string name = 4;
   repeated ToolCall tool_calls = 5;
   optional string tool_call_id = 6;
+  optional string error = 7;
 }