Add gpt-5.1 model definitions (#6551)

codex-rs/core/src/client_common.rs

@@ -421,6 +421,10 @@ mod tests {
                 slug: "gpt-5",
                 expects_apply_patch_instructions: true,
             },
+            InstructionsTestCase {
+                slug: "gpt-5.1",
+                expects_apply_patch_instructions: false,
+            },
             InstructionsTestCase {
                 slug: "codex-mini-latest",
                 expects_apply_patch_instructions: true,
@@ -433,6 +437,10 @@ mod tests {
                 slug: "gpt-5-codex",
                 expects_apply_patch_instructions: false,
             },
+            InstructionsTestCase {
+                slug: "gpt-5.1-codex",
+                expects_apply_patch_instructions: false,
+            },
         ];
         for test_case in test_cases {
             let model_family = find_family_for_model(test_case.slug).expect("known model slug");

codex-rs/core/src/model_family.rs

@@ -5,7 +5,9 @@ use crate::tools::spec::ConfigShellToolType;
 /// The `instructions` field in the payload sent to a model should always start
 /// with this content.
 const BASE_INSTRUCTIONS: &str = include_str!("../prompt.md");
+
 const GPT_5_CODEX_INSTRUCTIONS: &str = include_str!("../gpt_5_codex_prompt.md");
+const GPT_5_1_INSTRUCTIONS: &str = include_str!("../gpt_5_1_prompt.md");
 
 /// A model family is a group of models that share certain characteristics.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -154,7 +156,10 @@ pub fn find_family_for_model(slug: &str) -> Option<ModelFamily> {
         )
 
     // Production models.
-    } else if slug.starts_with("gpt-5-codex") || slug.starts_with("codex-") {
+    } else if slug.starts_with("gpt-5-codex")
+        || slug.starts_with("gpt-5.1-codex")
+        || slug.starts_with("codex-")
+    {
         model_family!(
             slug, slug,
             supports_reasoning_summaries: true,
@@ -163,6 +168,14 @@ pub fn find_family_for_model(slug: &str) -> Option<ModelFamily> {
             apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
             support_verbosity: false,
         )
+    } else if slug.starts_with("gpt-5.1") {
+        model_family!(
+            slug, "gpt-5.1",
+            supports_reasoning_summaries: true,
+            apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
+            support_verbosity: true,
+            base_instructions: GPT_5_1_INSTRUCTIONS.to_string(),
+        )
     } else if slug.starts_with("gpt-5") {
         model_family!(
             slug, "gpt-5",

codex-rs/core/src/openai_model_info.rs

@@ -70,7 +70,7 @@ pub(crate) fn get_model_info(model_family: &ModelFamily) -> Option<ModelInfo> {
         // https://platform.openai.com/docs/models/gpt-3.5-turbo
         "gpt-3.5-turbo" => Some(ModelInfo::new(16_385, 4_096)),
 
-        _ if slug.starts_with("gpt-5-codex") => {
+        _ if slug.starts_with("gpt-5-codex") || slug.starts_with("gpt-5.1-codex") => {
             Some(ModelInfo::new(CONTEXT_WINDOW_272K, MAX_OUTPUT_TOKENS_128K))
         }