core: strip image detail from Responses Lite requests (#27246)

## Summary - Strip image `detail` fields from every Responses Lite request. - Apply stripping to message images and function/custom tool-output images. - Transform only the formatted request copy without mutating stored history. - Preserve image URLs byte-for-byte, including HTTP(S) URLs, without downloading, validating, or resizing them. - Preserve all image `detail` fields for non-Responses-Lite models. ## Motivation Responses Lite does not support image `detail` tags, so Codex must omit them whenever `model_info.use_responses_lite` is enabled. This transport requirement is independent of the `resize_all_images` feature. Stored history retains the original detail values. This keeps request-specific formatting isolated from conversation state and preserves the information for local image preparation and non-Responses-Lite requests. #### [git stack](https://github.com/magus/git-stack-cli) - ✅ `1` https://github.com/openai/codex/pull/27245 - ✅ `2` https://github.com/openai/codex/pull/27247 - 👉 `3` https://github.com/openai/codex/pull/27246 - ⏳ `4` https://github.com/openai/codex/pull/27266
2026-07-01 00:31:56 +08:00 · 2026-06-10 20:43:03 -07:00
parent e614fad02e
commit 4435ff2810
4 changed files with 196 additions and 1 deletions
@@ -3,10 +3,95 @@ use codex_api::ResponsesApiRequest;
 use codex_api::TextControls;
 use codex_api::create_text_param_for_request;
 use codex_protocol::config_types::ServiceTier;
+use codex_protocol::models::FunctionCallOutputPayload;
+use codex_protocol::models::ImageDetail;
 use pretty_assertions::assert_eq;

 use super::*;

+fn prompt_with_image_outputs() -> Prompt {
+    Prompt {
+        input: vec![
+            ResponseItem::Message {
+                id: None,
+                role: "user".to_string(),
+                content: vec![ContentItem::InputImage {
+                    image_url: "https://example.com/image.png".to_string(),
+                    detail: Some(ImageDetail::Original),
+                }],
+                phase: None,
+            },
+            ResponseItem::FunctionCallOutput {
+                call_id: "function-call".to_string(),
+                output: FunctionCallOutputPayload::from_content_items(vec![
+                    FunctionCallOutputContentItem::InputImage {
+                        image_url: "data:image/png;base64,function".to_string(),
+                        detail: Some(ImageDetail::High),
+                    },
+                ]),
+            },
+            ResponseItem::CustomToolCallOutput {
+                call_id: "custom-call".to_string(),
+                name: None,
+                output: FunctionCallOutputPayload::from_content_items(vec![
+                    FunctionCallOutputContentItem::InputImage {
+                        image_url: "data:image/png;base64,custom".to_string(),
+                        detail: Some(ImageDetail::Auto),
+                    },
+                ]),
+            },
+        ],
+        ..Default::default()
+    }
+}
+
+#[test]
+fn responses_lite_request_copies_strip_image_details() {
+    let prompt = prompt_with_image_outputs();
+    let original = prompt.input.clone();
+
+    let stripped = prompt.get_formatted_input_for_request(/*use_responses_lite*/ true);
+
+    assert_eq!(
+        stripped,
+        vec![
+            ResponseItem::Message {
+                id: None,
+                role: "user".to_string(),
+                content: vec![ContentItem::InputImage {
+                    image_url: "https://example.com/image.png".to_string(),
+                    detail: None,
+                }],
+                phase: None,
+            },
+            ResponseItem::FunctionCallOutput {
+                call_id: "function-call".to_string(),
+                output: FunctionCallOutputPayload::from_content_items(vec![
+                    FunctionCallOutputContentItem::InputImage {
+                        image_url: "data:image/png;base64,function".to_string(),
+                        detail: None,
+                    },
+                ]),
+            },
+            ResponseItem::CustomToolCallOutput {
+                call_id: "custom-call".to_string(),
+                name: None,
+                output: FunctionCallOutputPayload::from_content_items(vec![
+                    FunctionCallOutputContentItem::InputImage {
+                        image_url: "data:image/png;base64,custom".to_string(),
+                        detail: None,
+                    },
+                ]),
+            },
+        ]
+    );
+    assert_eq!(prompt.input, original);
+    assert_eq!(
+        prompt.get_formatted_input_for_request(/*use_responses_lite*/ false),
+        original
+    );
+}
+
 #[test]
 fn serializes_text_verbosity_when_set() {
    let input: Vec<ResponseItem> = vec![];