fix(core): disable gpt-5 reasoning and raise output cap

Author: Bikz

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "goodcommit"
-version = "0.3.1"
+version = "0.3.2"
 edition = "2021"
 license = "MIT"
 description = "Good Commit: fast, reliable AI commit messages"

crates/cli/Cargo.toml

@@ -111,7 +111,7 @@ pub fn run_setup() -> Result<()> {
     config.one_line = Some(true);
     config.timeout_secs = Some(20);
     config.max_input_tokens = Some(6000);
-    config.max_output_tokens = Some(200);
+    config.max_output_tokens = Some(2048);
     config.stage_mode = Some(StageMode::Auto);
 
     let toml = toml::to_string_pretty(&config).context("failed to serialize config")?;

crates/cli/src/setup.rs

@@ -1,6 +1,6 @@
 [package]
 name = "goodcommit-core"
-version = "0.3.1"
+version = "0.3.2"
 edition = "2021"
 license = "MIT"
 description = "Core library for Good Commit"

crates/core/Cargo.toml

@@ -119,7 +119,7 @@ impl Config {
             push: Some(true),
             timeout_secs: Some(20),
             max_input_tokens: Some(6000),
-            max_output_tokens: Some(200),
+            max_output_tokens: Some(2048),
             max_file_bytes: Some(200_000),
             max_file_lines: Some(2_000),
             summary_concurrency: Some(4),
@@ -186,7 +186,7 @@ impl Config {
             push: self.push.unwrap_or(true),
             timeout_secs: self.timeout_secs.unwrap_or(20),
             max_input_tokens: self.max_input_tokens.unwrap_or(6000),
-            max_output_tokens: self.max_output_tokens.unwrap_or(200),
+            max_output_tokens: self.max_output_tokens.unwrap_or(2048),
             max_file_bytes: self.max_file_bytes.unwrap_or(200_000),
             max_file_lines: self.max_file_lines.unwrap_or(2_000),
             summary_concurrency: self.summary_concurrency.unwrap_or(4) as usize,

crates/core/src/config.rs

@@ -217,7 +217,7 @@ async fn summarize_then_commit(
     deadline: Instant,
 ) -> CoreResult<String> {
     let max_file_tokens = std::cmp::min(config.max_input_tokens as usize, 2000);
-    let summary_tokens = std::cmp::min(config.max_output_tokens, 120);
+    let summary_tokens = config.max_output_tokens;
     let concurrency = std::cmp::max(config.summary_concurrency, 1);
 
     let summary_results = stream::iter(diff_files.iter())

crates/core/src/pipeline.rs

@@ -98,7 +98,12 @@ impl OpenAiProvider {
         user_prompt: &str,
         request: ProviderRequest,
     ) -> CoreResult<String> {
-        let base = self.responses_base_payload(system_prompt, user_prompt, Some(request.temperature));
+        let temperature = if self.is_gpt5() {
+            None
+        } else {
+            Some(request.temperature)
+        };
+        let base = self.responses_base_payload(system_prompt, user_prompt, temperature);
 
         match self
             .complete_responses_with_fallbacks(&base, request.max_output_tokens)
@@ -123,11 +128,16 @@ impl OpenAiProvider {
         user_prompt: &str,
         request: ProviderRequest,
     ) -> CoreResult<String> {
+        let temperature = if self.is_gpt5() {
+            None
+        } else {
+            Some(request.temperature)
+        };
         let body = self.chat_payload(
             system_prompt,
             user_prompt,
             request.max_output_tokens,
-            Some(request.temperature),
+            temperature,
         );
 
         let http_request = self
@@ -182,6 +192,16 @@ impl OpenAiProvider {
         });
 
         if let Some(obj) = payload.as_object_mut() {
+            if self.is_gpt5() {
+                obj.insert(
+                    "reasoning".to_string(),
+                    serde_json::json!({ "effort": "none" }),
+                );
+                obj.insert(
+                    "text".to_string(),
+                    serde_json::json!({ "format": { "type": "text" } }),
+                );
+            }
             if let Some(value) = temperature {
                 obj.insert("temperature".to_string(), serde_json::json!(value));
             }
@@ -236,6 +256,10 @@ impl OpenAiProvider {
         }
     }
 
+    fn is_gpt5(&self) -> bool {
+        self.model.trim().to_lowercase().starts_with("gpt-5")
+    }
+
     async fn complete_responses_with_param(
         &self,
         base: &Value,
@@ -396,6 +420,41 @@ mod tests {
         assert!(payload.get("temperature").is_none());
     }
 
+    #[test]
+    fn responses_payload_sets_reasoning_none_for_gpt5() {
+        let provider = OpenAiProvider::new(
+            "gpt-5-nano-2025-08-07".to_string(),
+            "https://api.openai.com/v1".to_string(),
+            OpenAiMode::Responses,
+            5,
+            Some("test-key".to_string()),
+        )
+        .expect("provider");
+
+        let payload = provider.responses_base_payload("system", "user", None);
+        let effort = payload
+            .get("reasoning")
+            .and_then(|value| value.get("effort"))
+            .and_then(|value| value.as_str());
+        assert_eq!(effort, Some("none"));
+        assert!(payload.get("text").is_some());
+    }
+
+    #[test]
+    fn responses_payload_skips_reasoning_for_non_gpt5() {
+        let provider = OpenAiProvider::new(
+            "gpt-4o-mini".to_string(),
+            "https://api.openai.com/v1".to_string(),
+            OpenAiMode::Responses,
+            5,
+            Some("test-key".to_string()),
+        )
+        .expect("provider");
+
+        let payload = provider.responses_base_payload("system", "user", None);
+        assert!(payload.get("reasoning").is_none());
+    }
+
     #[test]
     fn chat_payload_omits_temperature_when_none() {
         let provider = OpenAiProvider::new(

crates/core/src/providers/openai.rs

@@ -1,14 +1,14 @@
 class Goodcommit < Formula
   desc "Good Commit: fast, reliable AI commit messages"
   homepage "https://github.com/Bikz/goodcommit"
-  version "0.3.1"
+  version "0.3.2"
 
   on_macos do
     if Hardware::CPU.arm?
-      url "https://github.com/Bikz/goodcommit/releases/download/v0.3.1/goodcommit-aarch64-apple-darwin.tar.gz"
+      url "https://github.com/Bikz/goodcommit/releases/download/v0.3.2/goodcommit-aarch64-apple-darwin.tar.gz"
       sha256 "REPLACE_ME"
     else
-      url "https://github.com/Bikz/goodcommit/releases/download/v0.3.1/goodcommit-x86_64-apple-darwin.tar.gz"
+      url "https://github.com/Bikz/goodcommit/releases/download/v0.3.2/goodcommit-x86_64-apple-darwin.tar.gz"
       sha256 "REPLACE_ME"
     end
   end
@@ -18,7 +18,7 @@ class Goodcommit < Formula
       odie "linux arm64 builds are not yet available"
     end
 
-    url "https://github.com/Bikz/goodcommit/releases/download/v0.3.1/goodcommit-x86_64-unknown-linux-gnu.tar.gz"
+    url "https://github.com/Bikz/goodcommit/releases/download/v0.3.2/goodcommit-x86_64-unknown-linux-gnu.tar.gz"
     sha256 "REPLACE_ME"
   end
 

homebrew/goodcommit.rb

@@ -1,6 +1,6 @@
 {
   "name": "goodcommit",
-  "version": "0.3.1",
+  "version": "0.3.2",
   "description": "Good Commit: fast, reliable AI commit messages",
   "license": "MIT",
   "repository": {