feat: Add "none" reasoning effort support for GPT-5.2 and GPT-5.1

CHANGELOG.md

@@ -2,6 +2,33 @@
 
 All notable changes to this project are documented here. Dates use the ISO format (YYYY-MM-DD).
 
+## [4.1.1] - 2025-12-11
+
+**Minor release**: "none" reasoning effort support for GPT-5.2 and GPT-5.1.
+
+### Added
+- **"none" reasoning effort support**: GPT-5.1 and GPT-5.2 support `reasoning_effort: "none"` which disables the reasoning phase entirely. This can result in faster responses when reasoning is not needed.
+  - `gpt-5.2-none` - GPT-5.2 with reasoning disabled
+  - `gpt-5.1-none` - GPT-5.1 with reasoning disabled
+- **4 new unit tests** for "none" reasoning behavior (now 197 total unit tests).
+
+### Technical Details
+- `getReasoningConfig()` now detects GPT-5.1 general purpose models (not Codex variants) and allows "none" to pass through.
+- GPT-5.2 inherits "none" support as it's newer than GPT-5.1.
+- Codex variants (gpt-5.1-codex, gpt-5.1-codex-max, gpt-5.1-codex-mini) do NOT support "none":
+  - Codex and Codex Max: "none" auto-converts to "low"
+  - Codex Mini: "none" auto-converts to "medium" (as before)
+- Documentation updated with complete reasoning effort support matrix per model family.
+
+### References
+- **OpenAI API docs** (`platform.openai.com/docs/api-reference/chat/create`): "gpt-5.1 defaults to none, which does not perform reasoning. The supported reasoning values for gpt-5.1 are none, low, medium, and high."
+- **Codex CLI** (`codex-rs/protocol/src/openai_models.rs`): `ReasoningEffort` enum includes `None` variant with `#[serde(rename_all = "lowercase")]` serialization to `"none"`.
+- **Codex CLI** (`codex-rs/core/src/client.rs`): Request builder passes `ReasoningEffort::None` through to API without validation/rejection.
+- **Codex CLI** (`docs/config.md`): Documents `model_reasoning_effort = "none"` as valid config option.
+
+### Notes
+- This plugin defaults to "medium" for better coding assistance; users must explicitly set "none" if desired.
+
 ## [4.1.0] - 2025-12-11
 
 **Feature release**: GPT 5.2 model support and image input capabilities.

docs/configuration.md

@@ -46,28 +46,35 @@ Complete reference for configuring the OpenCode OpenAI Codex Auth Plugin.
 
 Controls computational effort for reasoning.
 
-**GPT-5 Values:**
-- `minimal` - Fastest, least reasoning
+**GPT-5.2 Values** (per OpenAI API docs and Codex CLI `ReasoningEffort` enum):
+- `none` - No dedicated reasoning phase (disables reasoning)
+- `low` - Light reasoning
+- `medium` - Balanced (default)
+- `high` - Deep reasoning
+- `xhigh` - Extra depth for long-horizon tasks
+
+**GPT-5.1 Values** (per OpenAI API docs and Codex CLI `ReasoningEffort` enum):
+- `none` - No dedicated reasoning phase (disables reasoning)
 - `low` - Light reasoning
 - `medium` - Balanced (default)
 - `high` - Deep reasoning
 
-**GPT-5-Codex Values:**
+**GPT-5.1-Codex / GPT-5.1-Codex-Max Values:**
 - `low` - Fastest for code
 - `medium` - Balanced (default)
 - `high` - Maximum code quality
+- `xhigh` - Extra depth (Codex Max only)
 
-**GPT-5.1-Codex-Max Values:**
-- `none` - No dedicated reasoning phase
-- `low` - Light reasoning
-- `medium` - Balanced
-- `high` - Deep reasoning (default for this family)
-- `xhigh` - Extra depth for long-horizon tasks
+**GPT-5.1-Codex-Mini Values:**
+- `medium` - Balanced (default)
+- `high` - Maximum code quality
 
 **Notes**:
+- `none` is supported for GPT-5.2 and GPT-5.1 (general purpose) per OpenAI API documentation
+- `none` is NOT supported for Codex variants - it auto-converts to `low` for Codex or `medium` for Codex Mini
 - `minimal` auto-converts to `low` for Codex models
-- `gpt-5-codex-mini*` and `gpt-5.1-codex-mini*` only support `medium` or `high`; lower settings are clamped to `medium` and `xhigh` downgrades to `high`
-- Codex Max supports `none` and `xhigh` and defaults to `high` when not specified
+- `xhigh` is only supported for GPT-5.2 and GPT-5.1-Codex-Max; other models downgrade to `high`
+- Codex Mini only supports `medium` or `high`; lower settings clamp to `medium`
 
 **Example:**
 ```json

lib/request/helpers/model-map.ts

@@ -30,9 +30,10 @@ export const MODEL_MAP: Record<string, string> = {
 	"gpt-5.1-codex-max-xhigh": "gpt-5.1-codex-max",
 
 	// ============================================================================
-	// GPT-5.2 Models (same reasoning support as Codex Max: low/medium/high/xhigh)
+	// GPT-5.2 Models (supports none/low/medium/high/xhigh per OpenAI API docs)
 	// ============================================================================
 	"gpt-5.2": "gpt-5.2",
+	"gpt-5.2-none": "gpt-5.2",
 	"gpt-5.2-low": "gpt-5.2",
 	"gpt-5.2-medium": "gpt-5.2",
 	"gpt-5.2-high": "gpt-5.2",
@@ -46,9 +47,10 @@ export const MODEL_MAP: Record<string, string> = {
 	"gpt-5.1-codex-mini-high": "gpt-5.1-codex-mini",
 
 	// ============================================================================
-	// GPT-5.1 General Purpose Models
+	// GPT-5.1 General Purpose Models (supports none/low/medium/high per OpenAI API docs)
 	// ============================================================================
 	"gpt-5.1": "gpt-5.1",
+	"gpt-5.1-none": "gpt-5.1",
 	"gpt-5.1-low": "gpt-5.1",
 	"gpt-5.1-medium": "gpt-5.1",
 	"gpt-5.1-high": "gpt-5.1",

lib/request/request-transformer.ts

@@ -146,10 +146,26 @@ export function getReasoningConfig(
 		(normalizedName.includes("nano") ||
 			normalizedName.includes("mini"));
 
+	// GPT-5.1 general purpose (not codex variants) - supports "none" per OpenAI API docs
+	const isGpt51General =
+		(normalizedName.includes("gpt-5.1") || normalizedName.includes("gpt 5.1")) &&
+		!isCodex &&
+		!isCodexMax &&
+		!isCodexMini;
+
 	// GPT 5.2 and Codex Max support xhigh reasoning
 	const supportsXhigh = isGpt52 || isCodexMax;
 
+	// GPT 5.1 and GPT 5.2 support "none" reasoning per:
+	// - OpenAI API docs: "gpt-5.1 defaults to none, supports: none, low, medium, high"
+	// - Codex CLI: ReasoningEffort enum includes None variant (codex-rs/protocol/src/openai_models.rs)
+	// - Codex CLI: docs/config.md lists "none" as valid for model_reasoning_effort
+	// - gpt-5.2 (being newer) also supports: none, low, medium, high, xhigh
+	const supportsNone = isGpt52 || isGpt51General;
+
 	// Default based on model type (Codex CLI defaults)
+	// Note: OpenAI docs say gpt-5.1 defaults to "none", but we default to "medium"
+	// for better coding assistance unless user explicitly requests "none"
 	const defaultEffort: ReasoningConfig["effort"] = isCodexMini
 		? "medium"
 		: supportsXhigh
@@ -178,6 +194,12 @@ export function getReasoningConfig(
 		effort = "high";
 	}
 
+	// For models that don't support "none", upgrade to "low"
+	// (Codex models don't support "none" - only GPT-5.1 and GPT-5.2 general purpose do)
+	if (!supportsNone && effort === "none") {
+		effort = "low";
+	}
+
 	// Normalize "minimal" to "low" for Codex families
 	// Codex CLI presets are low/medium/high (or xhigh for Codex Max)
 	if (isCodex && effort === "minimal") {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "opencode-openai-codex-auth",
-  "version": "4.1.0",
+  "version": "4.1.1",
   "description": "OpenAI ChatGPT (Codex backend) OAuth auth plugin for opencode - use your ChatGPT Plus/Pro subscription instead of API credits",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",

test/request-transformer.test.ts

@@ -825,6 +825,62 @@ describe('Request Transformer Module', () => {
 			expect(result.reasoning?.effort).toBe('high');
 		});
 
+		it('should preserve none for GPT-5.2', async () => {
+			const body: RequestBody = {
+				model: 'gpt-5.2-none',
+				input: [],
+			};
+			const userConfig: UserConfig = {
+				global: { reasoningEffort: 'none' },
+				models: {},
+			};
+			const result = await transformRequestBody(body, codexInstructions, userConfig);
+			expect(result.model).toBe('gpt-5.2');
+			expect(result.reasoning?.effort).toBe('none');
+		});
+
+		it('should preserve none for GPT-5.1 general purpose', async () => {
+			const body: RequestBody = {
+				model: 'gpt-5.1-none',
+				input: [],
+			};
+			const userConfig: UserConfig = {
+				global: { reasoningEffort: 'none' },
+				models: {},
+			};
+			const result = await transformRequestBody(body, codexInstructions, userConfig);
+			expect(result.model).toBe('gpt-5.1');
+			expect(result.reasoning?.effort).toBe('none');
+		});
+
+		it('should upgrade none to low for GPT-5.1-codex (codex does not support none)', async () => {
+			const body: RequestBody = {
+				model: 'gpt-5.1-codex',
+				input: [],
+			};
+			const userConfig: UserConfig = {
+				global: { reasoningEffort: 'none' },
+				models: {},
+			};
+			const result = await transformRequestBody(body, codexInstructions, userConfig);
+			expect(result.model).toBe('gpt-5.1-codex');
+			expect(result.reasoning?.effort).toBe('low');
+		});
+
+		it('should upgrade none to low for GPT-5.1-codex-max (codex max does not support none)', async () => {
+			const body: RequestBody = {
+				model: 'gpt-5.1-codex-max',
+				input: [],
+			};
+			const userConfig: UserConfig = {
+				global: { reasoningEffort: 'none' },
+				models: {},
+			};
+			const result = await transformRequestBody(body, codexInstructions, userConfig);
+			expect(result.model).toBe('gpt-5.1-codex-max');
+			expect(result.reasoning?.effort).toBe('low');
+		});
+
 		it('should preserve minimal for non-codex models', async () => {
 			const body: RequestBody = {
 				model: 'gpt-5',