Update image outputs to default to high detail (#18386)

Do not assume the default `detail`.

codex-rs/code-mode/src/description.rs

@@ -26,7 +26,7 @@ const EXEC_DESCRIPTION_TEMPLATE: &str = r#"Run JavaScript code to orchestrate/co
 - Global helpers:
 - `exit()`: Immediately ends the current script successfully (like an early return from the top level).
 - `text(value: string | number | boolean | undefined | null)`: Appends a text item. Non-string values are stringified with `JSON.stringify(...)` when possible.
-- `image(imageUrlOrItem: string | { image_url: string; detail?: "auto" | "low" | "high" | "original" | null } | ImageContent, detail?: "auto" | "low" | "high" | "original" | null)`: Appends an image item. `image_url` can be an HTTPS URL or a base64-encoded `data:` URL. To forward an MCP tool image, pass an individual `ImageContent` block from `result.content`, for example `image(result.content[0])`. MCP image blocks may request original detail with `_meta: { "codex/imageDetail": "original" }`. When provided, the second `detail` argument overrides any detail embedded in the first argument.
+- `image(imageUrlOrItem: string | { image_url: string; detail?: "auto" | "low" | "high" | "original" | null } | ImageContent, detail?: "auto" | "low" | "high" | "original" | null)`: Appends an image item. `image_url` can be an HTTPS URL or a base64-encoded `data:` URL. To forward an MCP tool image, pass an individual `ImageContent` block from `result.content`, for example `image(result.content[0])`. MCP image blocks may request detail with `_meta: { "codex/imageDetail": "original" }`. When provided, the second `detail` argument overrides any detail embedded in the first argument.
 - `store(key: string, value: any)`: stores a serializable value under a string key for later `exec` calls in the same session.
 - `load(key: string)`: returns the stored value for a string key, or `undefined` if it is missing.
 - `notify(value: string | number | boolean | undefined | null)`: immediately injects an extra `custom_tool_call_output` for the current `exec` call. Values are stringified like `text(...)`.

codex-rs/code-mode/src/lib.rs

@@ -15,6 +15,7 @@ pub use description::normalize_code_mode_identifier;
 pub use description::parse_exec_source;
 pub use description::render_code_mode_sample;
 pub use description::render_json_schema_to_typescript;
+pub use response::DEFAULT_IMAGE_DETAIL;
 pub use response::FunctionCallOutputContentItem;
 pub use response::ImageDetail;
 pub use runtime::DEFAULT_EXEC_YIELD_TIME_MS;

codex-rs/code-mode/src/response.rs

@@ -10,6 +10,8 @@ pub enum ImageDetail {
     Original,
 }
 
+pub const DEFAULT_IMAGE_DETAIL: ImageDetail = ImageDetail::High;
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum FunctionCallOutputContentItem {

codex-rs/code-mode/src/runtime/value.rs

@@ -1,5 +1,6 @@
 use serde_json::Value as JsonValue;
 
+use crate::response::DEFAULT_IMAGE_DETAIL;
 use crate::response::FunctionCallOutputContentItem;
 use crate::response::ImageDetail;
 
@@ -81,7 +82,7 @@ pub(super) fn normalize_output_image(
                     }
                 })
             }
-            None => None,
+            None => Some(DEFAULT_IMAGE_DETAIL),
         };
 
         Ok(FunctionCallOutputContentItem::InputImage { image_url, detail })
@@ -159,7 +160,7 @@ fn parse_mcp_output_image(
         .and_then(JsonValue::as_object)
         .and_then(|meta| meta.get(CODEX_IMAGE_DETAIL_META_KEY))
         .and_then(JsonValue::as_str)
-        .filter(|detail| *detail == "original")
+        .filter(|detail| matches!(*detail, "auto" | "low" | "high" | "original"))
         .map(str::to_string);
     Ok((image_url, detail))
 }

codex-rs/code-mode/src/service.rs

@@ -669,7 +669,7 @@ text(JSON.stringify(returnsUndefined));
                     },
                     FunctionCallOutputContentItem::InputImage {
                         image_url: "https://example.com/image.jpg".to_string(),
-                        detail: None,
+                        detail: Some(crate::DEFAULT_IMAGE_DETAIL),
                     },
                     FunctionCallOutputContentItem::InputText {
                         text: "[true,true,true]".to_string(),