From 35c3daaecfd2be76ad74a282164d4323c35ff599 Mon Sep 17 00:00:00 2001
From: Richard Feldman <richard@zed.dev>
Date: Thu, 11 Dec 2025 16:17:58 -0500
Subject: [PATCH] Add GPT-5.2 support (cherry-pick to preview) (#44662)

Cherry-pick of 541e08683565f9e4e950ef3895bd28048fd4f317 to preview

----
---
 crates/language_models/src/provider/open_ai.rs | 8 ++++++--
 crates/open_ai/src/open_ai.rs                  | 8 ++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/crates/language_models/src/provider/open_ai.rs b/crates/language_models/src/provider/open_ai.rs
index 32ee95ce9bd423bf7f66efc1bc7440455380ab5c..403b025f518681f335f28e35d11450bef046fca2 100644
--- a/crates/language_models/src/provider/open_ai.rs
+++ b/crates/language_models/src/provider/open_ai.rs
@@ -278,6 +278,7 @@ impl LanguageModel for OpenAiLanguageModel {
             | Model::FiveMini
             | Model::FiveNano
             | Model::FivePointOne
+            | Model::FivePointTwo
             | Model::O1
             | Model::O3
             | Model::O4Mini => true,
@@ -675,8 +676,11 @@ pub fn count_open_ai_tokens(
             | Model::O4Mini
             | Model::Five
             | Model::FiveMini
-            | Model::FiveNano => tiktoken_rs::num_tokens_from_messages(model.id(), &messages), // GPT-5.1 doesn't have tiktoken support yet; fall back on gpt-4o tokenizer
-            Model::FivePointOne => tiktoken_rs::num_tokens_from_messages("gpt-5", &messages),
+            | Model::FiveNano => tiktoken_rs::num_tokens_from_messages(model.id(), &messages),
+            // GPT-5.1 and 5.2 don't have dedicated tiktoken support; use gpt-5 tokenizer
+            Model::FivePointOne | Model::FivePointTwo => {
+                tiktoken_rs::num_tokens_from_messages("gpt-5", &messages)
+            }
         }
         .map(|tokens| tokens as u64)
     })
diff --git a/crates/open_ai/src/open_ai.rs b/crates/open_ai/src/open_ai.rs
index 8ed70c9dd514cb59f5c7a160169031cbc28428e6..d8b472254383b673e9a9e60b728d2ae585a69b90 100644
--- a/crates/open_ai/src/open_ai.rs
+++ b/crates/open_ai/src/open_ai.rs
@@ -87,6 +87,8 @@ pub enum Model {
     FiveNano,
     #[serde(rename = "gpt-5.1")]
     FivePointOne,
+    #[serde(rename = "gpt-5.2")]
+    FivePointTwo,
     #[serde(rename = "custom")]
     Custom {
         name: String,
@@ -123,6 +125,7 @@ impl Model {
             "gpt-5-mini" => Ok(Self::FiveMini),
             "gpt-5-nano" => Ok(Self::FiveNano),
             "gpt-5.1" => Ok(Self::FivePointOne),
+            "gpt-5.2" => Ok(Self::FivePointTwo),
             invalid_id => anyhow::bail!("invalid model id '{invalid_id}'"),
         }
     }
@@ -145,6 +148,7 @@ impl Model {
             Self::FiveMini => "gpt-5-mini",
             Self::FiveNano => "gpt-5-nano",
             Self::FivePointOne => "gpt-5.1",
+            Self::FivePointTwo => "gpt-5.2",
             Self::Custom { name, .. } => name,
         }
     }
@@ -167,6 +171,7 @@ impl Model {
             Self::FiveMini => "gpt-5-mini",
             Self::FiveNano => "gpt-5-nano",
             Self::FivePointOne => "gpt-5.1",
+            Self::FivePointTwo => "gpt-5.2",
             Self::Custom {
                 name, display_name, ..
             } => display_name.as_ref().unwrap_or(name),
@@ -191,6 +196,7 @@ impl Model {
             Self::FiveMini => 272_000,
             Self::FiveNano => 272_000,
             Self::FivePointOne => 400_000,
+            Self::FivePointTwo => 400_000,
             Self::Custom { max_tokens, .. } => *max_tokens,
         }
     }
@@ -216,6 +222,7 @@ impl Model {
             Self::FiveMini => Some(128_000),
             Self::FiveNano => Some(128_000),
             Self::FivePointOne => Some(128_000),
+            Self::FivePointTwo => Some(128_000),
         }
     }
 
@@ -244,6 +251,7 @@ impl Model {
             | Self::Five
             | Self::FiveMini
             | Self::FivePointOne
+            | Self::FivePointTwo
             | Self::FiveNano => true,
             Self::O1 | Self::O3 | Self::O3Mini | Self::O4Mini | Model::Custom { .. } => false,
         }