diff --git a/README.md b/README.md
index 4298c5f9..be2cc935 100644
--- a/README.md
+++ b/README.md
@@ -200,7 +200,7 @@ Every item below is one more layer sedimented into a default — a capability yo
 - **Toggle and push-to-talk** recording modes, plus a **MediaPlayPause trigger** so wired-earbud inline controls can start and stop recording. `Esc` cancels at any phase, including polish and insertion.
 - **Cloud ASR**: Volcengine streaming ASR (bigasr), iFlytek realtime ASR (RTASR), Alibaba Cloud Bailian (classic realtime / Qwen3 realtime / Fun-ASR-Flash file transcription), StepFun StepAudio (batch + realtime), Zhipu GLM-ASR, Xiaomi MiMo ASR, ElevenLabs Scribe, OpenAI-compatible batch transcription (OpenAI Whisper / Groq / SiliconFlow SenseVoice / OpenRouter / ZenMux), and Apple Speech (macOS).
 - **Local ASR**: bundled Qwen3-ASR (0.6B / 1.7B) via vendored `Open-Less/qwen-asr` (macOS); Windows Foundry Local Whisper and sherpa-onnx (experimental) variants.
-- **Polish providers**: Ark (Volcengine), DeepSeek, OpenAI, Google Gemini, Codex OAuth, SiliconFlow, Atlas Cloud, Xiaomi MiMo, CometAPI, OpenRouter, Alibaba Cloud Coding Plan, CodingPlanX, MiniMax, and StepFun — plus any OpenAI-compatible endpoint you bring.
+- **Polish providers**: Ark (Volcengine), DeepSeek, OpenAI, Google Gemini, Codex OAuth, SiliconFlow, Atlas Cloud, Xiaomi MiMo, CometAPI, OpenRouter, Alibaba Cloud Coding Plan, CodingPlanX, MiniMax, StepFun, and OpenCode Zen — plus any OpenAI-compatible endpoint you bring.
 - **Four output modes**: raw, light polish, structured (**AI-prompt mode**), and formal. Plus a **translation hotkey** that converts speech directly into the configured target language ([#43](../../issues/43)).
 - **Selection-ask QA panel** — a separate hotkey opens a floating panel that runs voice Q&A against the highlighted text in any app ([#118](../../issues/118)).
 - **Main window**: Overview / History / Vocab / Style / Marketplace / Settings. Persistent tray icon, plus a mini status capsule that floats on screen and follows the display you are typing on (multi-monitor).
diff --git a/README.zh.md b/README.zh.md
index 14e93de1..052e317a 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -205,7 +205,7 @@ OpenLess 只做一件事:**把语音变成可用的书面文字(尤其是 AI 提
 - **切换式与按住说话(push-to-talk)** 两种录音模式,外加 **MediaPlayPause 触发**,让有线耳机的线控也能开始 / 停止录音。`Esc` 可在任意阶段取消,包括润色与插入。
 - **云端 ASR**:Volcengine 流式 ASR(bigasr)、讯飞实时语音转写(RTASR)、阿里云百炼(经典实时 / Qwen3 实时 / Fun-ASR-Flash 录音文件)、阶跃星辰 StepAudio(批式 + 实时)、智谱 GLM-ASR、小米 MiMo ASR、ElevenLabs Scribe、OpenAI 兼容批量转写(OpenAI Whisper / Groq / 硅基流动 SenseVoice / OpenRouter / ZenMux),以及 Apple Speech(macOS)。
 - **本地 ASR**:通过 vendored 的 `Open-Less/qwen-asr` 内置 Qwen3-ASR(0.6B / 1.7B)(macOS);Windows 上的 Foundry Local Whisper 与 sherpa-onnx(实验性)变体。
-- **润色提供方**:Ark(火山方舟)、DeepSeek、OpenAI、Google Gemini、Codex OAuth、硅基流动、Atlas Cloud、小米 MiMo、CometAPI、OpenRouter、阿里云 Coding Plan、CodingPlanX、MiniMax、StepFun,以及你自带的任意 OpenAI 兼容端点。
+- **润色提供方**:Ark(火山方舟)、DeepSeek、OpenAI、Google Gemini、Codex OAuth、硅基流动、Atlas Cloud、小米 MiMo、CometAPI、OpenRouter、阿里云 Coding Plan、CodingPlanX、MiniMax、StepFun、OpenCode Zen,以及你自带的任意 OpenAI 兼容端点。
 - **四种输出模式**:原文、轻度润色、结构化(**AI 提示词模式**)、正式。另有一个**翻译快捷键**,将语音直接转换为所配置的目标语言([#43](../../issues/43))。
 - **选区问答面板**——一个独立快捷键打开浮动面板,针对任意应用中被高亮选中的文本进行语音问答([#118](../../issues/118))。
 - **主窗口**:概览 / 历史 / 词典 / 风格 / 市场 / 设置。常驻托盘图标,以及一个浮于屏幕、并跟随你正在输入的显示器的迷你状态胶囊(多显示器)。
diff --git a/openless-all/app/crates/openless-core/src/cloud_providers.rs b/openless-all/app/crates/openless-core/src/cloud_providers.rs
index e95d49ae..54113e64 100644
--- a/openless-all/app/crates/openless-core/src/cloud_providers.rs
+++ b/openless-all/app/crates/openless-core/src/cloud_providers.rs
@@ -76,6 +76,7 @@ pub const SHARED_CLOUD_LLM_PROVIDER_TYPES: &[&str] = &[
     "codingPlanX",
     "minimax",
     "stepfun",
+    "opencode",
     "custom",
     "custom_responses",
     "custom_messages",
diff --git a/openless-all/app/crates/openless-core/src/polish.rs b/openless-all/app/crates/openless-core/src/polish.rs
index 694fefb7..23857658 100644
--- a/openless-all/app/crates/openless-core/src/polish.rs
+++ b/openless-all/app/crates/openless-core/src/polish.rs
@@ -187,6 +187,7 @@ fn is_builtin_llm_provider(provider_id: &str) -> bool {
             | "codingPlanX"
             | "minimax"
             | "stepfun"
+            | "opencode"
     )
 }
 
@@ -1649,8 +1650,21 @@ pub(crate) fn apply_openai_compatible_thinking_control(
 ) {
     // 优先按 provider_id 预设分派；custom / 未声明 provider 时回退到 base_url 兜底,
     // 让用户用"自定义"preset 接入 MiniMax 也能正确下发 thinking 控制参数。
-    let control = openai_compatible_thinking_control(provider_id)
-        .or_else(|| openai_compatible_thinking_control_for_base_url(base_url));
+    // Zen 是多模型网关，仅 DeepSeek 模型使用 DeepSeek 的思考参数。
+    let is_opencode = provider_id.trim() == "opencode"
+        || (matches!(provider_id.trim(), "custom" | "custom_responses" | "custom_messages")
+            && url::Url::parse(base_url.trim())
+                .ok()
+                .is_some_and(|url| url.host_str() == Some("opencode.ai")));
+    let control = if is_opencode {
+        model
+            .trim()
+            .starts_with("deepseek-")
+            .then_some(ThinkingControl::DeepSeekThinking)
+    } else {
+        openai_compatible_thinking_control(provider_id)
+            .or_else(|| openai_compatible_thinking_control_for_base_url(base_url))
+    };
     match control {
         Some(ThinkingControl::ReasoningEffort) => {
             // OpenAI 官方 Chat Completions 只在推理模型族接受 reasoning_effort；
@@ -2125,7 +2139,10 @@ mod tests {
 
     #[tokio::test]
     async fn all_text_entrypoints_use_the_selected_protocol_over_http() {
-        for format in LlmRequestFormat::ALL {
+        for (format, (preset, prefix)) in LlmRequestFormat::ALL.into_iter().flat_map(|format| {
+            [("custom", "/gateway/v1"), ("opencode", "/zen/v1"), ("opencode", "/zen/go/v1")]
+                .map(|entry| (format, entry))
+        }) {
             let listener = TcpListener::bind("127.0.0.1:0").unwrap();
             let address = listener.local_addr().unwrap();
             let server = thread::spawn(move || {
@@ -2140,7 +2157,7 @@ mod tests {
                         LlmRequestFormat::Responses => "responses",
                         LlmRequestFormat::Messages => "messages",
                     };
-                    assert!(headers.starts_with(&format!("post /gateway/v1/{path}?tenant=1 ")));
+                    assert!(headers.starts_with(&format!("post {prefix}/{path}?tenant=1 ")));
                     if format == LlmRequestFormat::Messages {
                         assert!(headers.contains("x-api-key: fixture-key"));
                         assert!(headers.contains("anthropic-version: 2023-06-01"));
@@ -2189,9 +2206,9 @@ mod tests {
                 }
             });
             let config = OpenAICompatibleConfig::new(
-                "custom",
+                preset,
                 "test",
-                format!("http://{address}/gateway/v1/chat/completions?tenant=1"),
+                format!("http://{address}{prefix}/chat/completions?tenant=1"),
                 "fixture-key",
                 "test",
             )
@@ -2283,6 +2300,52 @@ mod tests {
         }
     }
 
+    #[test]
+    fn opencode_thinking_is_scoped_to_model_host_and_protocol() {
+        for (preset, endpoint, zen) in [
+            ("opencode", "https://opencode.ai/zen/v1", true),
+            ("opencode", "https://gateway.example/v1", true),
+            ("custom", "https://opencode.ai/zen/v1", true),
+            ("custom_responses", "https://opencode.ai/zen/v1", true),
+            ("custom_messages", "https://opencode.ai/zen/v1", true),
+            ("custom", "https://OPENCODE.AI:443/zen/go/v1/chat/completions", true),
+            ("custom", "https://opencode.ai.example/zen/v1", false),
+            ("custom", "https://fakeopencode.ai/zen/v1", false),
+            ("custom", "https://opencode.ai@example.com/zen/v1", false),
+            ("custom", "https://example.com/opencode.ai", false),
+        ] {
+            for model in ["deepseek-v4-flash", "minimax-m3", "gateway-model"] {
+                for enabled in [false, true] {
+                    for format in LlmRequestFormat::ALL {
+                        let provider = OpenAICompatibleLLMProvider::new(
+                            OpenAICompatibleConfig::new(preset, "test", endpoint, "key", model)
+                                .with_thinking_enabled(enabled)
+                                .with_protocol(LlmProtocolConfig { format, ..Default::default() }),
+                        );
+                        let body = provider.chat_body(false, vec![json!({"role":"user","content":"hi"})]);
+                        match format {
+                            LlmRequestFormat::ChatCompletions if zen && model.starts_with("deepseek-") => {
+                                assert_eq!(body["thinking"]["type"], if enabled { "enabled" } else { "disabled" });
+                            }
+                            LlmRequestFormat::Messages if enabled => {
+                                assert_eq!(body["thinking"]["type"], "adaptive");
+                            }
+                            _ => assert!(body.get("thinking").is_none(), "{preset} {endpoint} {model} {format:?}"),
+                        }
+                        assert!(body.get("reasoning_effort").is_none());
+                        assert!(body.get("enable_thinking").is_none());
+                        if format == LlmRequestFormat::Responses {
+                            assert_eq!(body["reasoning"]["effort"], if enabled { "medium" } else { "low" });
+                            assert!(body.get("messages").is_none());
+                        } else {
+                            assert!(body.get("reasoning").is_none());
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     fn write_chunked_sse_response(stream: &mut std::net::TcpStream, chunks: &[&[u8]]) {
         stream
             .write_all(
diff --git a/openless-all/app/crates/openless-core/src/provider_rules.rs b/openless-all/app/crates/openless-core/src/provider_rules.rs
index 6ab43ab8..e79f9e20 100644
--- a/openless-all/app/crates/openless-core/src/provider_rules.rs
+++ b/openless-all/app/crates/openless-core/src/provider_rules.rs
@@ -62,6 +62,7 @@ const LLM_PROVIDER_TYPES: &[(&str, &str)] = &[
     ("codingPlanX", "codingPlanX"),
     ("minimax", "minimax"),
     ("stepfun", "stepfun"),
+    ("opencode", "opencode"),
     ("custom", "customChatCompletions"),
     ("custom_responses", "customResponses"),
     ("custom_messages", "customMessages"),
@@ -481,6 +482,7 @@ pub fn default_asr_model(provider_type: &str) -> Option<&'static str> {
 
 pub fn default_llm_endpoint(provider_type: &str) -> Option<&'static str> {
     match provider_type {
+        "opencode" => Some("https://opencode.ai/zen/v1"),
         "ark" => Some("https://ark.cn-beijing.volces.com/api/v3"),
         "deepseek" => Some("https://api.deepseek.com/v1"),
         "siliconflow" => Some("https://api.siliconflow.cn/v1"),
@@ -501,7 +503,7 @@ pub fn default_llm_endpoint(provider_type: &str) -> Option<&'static str> {
 pub fn default_llm_model(provider_type: &str) -> Option<&'static str> {
     match provider_type {
         "ark" => Some("deepseek-v3-2"),
-        "deepseek" => Some("deepseek-v4-flash"),
+        "deepseek" | "opencode" => Some("deepseek-v4-flash"),
         "siliconflow" => Some("Qwen/Qwen2.5-7B-Instruct"),
         "atlascloud" => Some("qwen/qwen3.5-flash"),
         "openai" | "cometapi" => Some("gpt-4o"),
@@ -989,6 +991,29 @@ mod tests {
         assert!(parse_extra_headers(r#"{"authorization":"secret"}"#).is_err());
     }
 
+    #[test]
+    fn opencode_descriptor_supplies_defaults_formats_and_credentials() {
+        use crate::llm_protocol::LlmRequestFormat;
+        assert!(crate::cloud_providers::SHARED_CLOUD_LLM_PROVIDER_TYPES.contains(&"opencode"));
+        let descriptor = provider_descriptor(ProviderKind::Llm, "opencode").unwrap();
+        assert_eq!(descriptor.label_key, "opencode");
+        assert_eq!(descriptor.default_endpoint.as_deref(), Some("https://opencode.ai/zen/v1"));
+        assert_eq!(descriptor.default_model.as_deref(), Some("deepseek-v4-flash"));
+        assert_eq!(descriptor.default_request_format, Some(LlmRequestFormat::ChatCompletions));
+        assert_eq!(descriptor.supported_request_formats, LlmRequestFormat::ALL);
+        assert_eq!(descriptor.validation_probe, ValidationProbe::LlmText);
+        assert!(api_key_required(ProviderKind::Llm, "opencode", Some("https://opencode.ai/zen/v1/chat/completions/")));
+        let mut configuration = CredentialConfiguration {
+            llm_endpoint: true,
+            llm_endpoint_matches_default: true,
+            llm_model: true,
+            ..CredentialConfiguration::default()
+        };
+        assert!(!llm_configured("opencode", &configuration));
+        configuration.llm_api_key = true;
+        assert!(llm_configured("opencode", &configuration));
+    }
+
     #[test]
     fn descriptors_are_the_single_source_for_defaults_auth_and_probes() {
         let compatible = provider_descriptor(ProviderKind::Asr, "openai-compatible").unwrap();
diff --git a/openless-all/app/crates/openless-core/src/provider_service.rs b/openless-all/app/crates/openless-core/src/provider_service.rs
index 1256553f..a4d1c2d4 100644
--- a/openless-all/app/crates/openless-core/src/provider_service.rs
+++ b/openless-all/app/crates/openless-core/src/provider_service.rs
@@ -892,6 +892,9 @@ mod tests {
     async fn validation_and_model_lists_use_channel_protocol_and_thinking() {
         use crate::llm_protocol::*;
         for (format, preset, sse, path) in [
+            ("chat_completions", "opencode", "data: {\"choices\":[{\"delta\":{\"content\":\"ok\"}}]}\n\ndata: [DONE]\n\n", "/v1/chat/completions"),
+            ("responses", "opencode", "data: {\"type\":\"response.output_text.delta\",\"delta\":\"ok\"}\n\ndata: {\"type\":\"response.completed\"}\n\n", "/v1/responses"),
+            ("messages", "opencode", "data: {\"type\":\"content_block_delta\",\"delta\":{\"type\":\"text_delta\",\"text\":\"ok\"}}\n\ndata: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\"}}\n\ndata: {\"type\":\"message_stop\"}\n\n", "/v1/messages"),
             ("responses", "custom_responses", "data: {\"type\":\"response.output_text.delta\",\"delta\":\"ok\"}\n\ndata: {\"type\":\"response.completed\"}\n\n", "/v1/responses"),
             ("messages", "custom_messages", "data: {\"type\":\"content_block_delta\",\"delta\":{\"type\":\"text_delta\",\"text\":\"ok\"}}\n\ndata: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\"}}\n\ndata: {\"type\":\"message_stop\"}\n\n", "/v1/messages"),
         ] {
@@ -909,13 +912,13 @@ mod tests {
                 assert!(request.starts_with(&format!("POST {path} ")));
                 let body: serde_json::Value = serde_json::from_str(request.split_once("\r\n\r\n").unwrap().1).unwrap();
                 if format == "responses" { assert_eq!(body["reasoning"]["effort"], if enabled { "medium" } else { "low" }); }
-                else if enabled { assert_eq!(body["thinking"]["type"], "adaptive"); }
+                else if format == "messages" && enabled { assert_eq!(body["thinking"]["type"], "adaptive"); }
                 else { assert!(body.get("thinking").is_none()); }
             }
             let (endpoint, request) = spawn_http_response("200 OK", "application/json", r#"{"data":[{"id":"model"}]}"#);
             let credentials = Arc::new(InMemoryCredentialStore::default());
-            let channel = create_channel_with_values(&credentials, ChannelKind::Llm, "openai", &[
-                (LLM_ENDPOINT_ACCOUNT, &format!("{endpoint}/{format}")), (LLM_MODEL_ACCOUNT, "test"),
+            let channel = create_channel_with_values(&credentials, ChannelKind::Llm, preset, &[
+                (LLM_ENDPOINT_ACCOUNT, &format!("{endpoint}/{}", if format == "chat_completions" { "chat/completions" } else { format })), (LLM_MODEL_ACCOUNT, "test"),
                 (LLM_API_KEY_ACCOUNT, "fixture-key"), (REQUEST_FORMAT_ACCOUNT, format),
             ]).await;
             let service = ProviderService::new(credentials, Arc::new(crate::TokioTaskSpawner));
diff --git a/openless-all/app/src/i18n/en.ts b/openless-all/app/src/i18n/en.ts
index 15b0101c..700a94ad 100644
--- a/openless-all/app/src/i18n/en.ts
+++ b/openless-all/app/src/i18n/en.ts
@@ -1010,6 +1010,7 @@ export const en: typeof zhCN = {
         codingPlanX: 'CodingPlanX',
         minimax: 'MiniMax (M3)',
         stepfun: 'StepFun',
+        opencode: 'OpenCode Zen',
         customChatCompletions: "Custom · Chat Completions",
         customResponses: "Custom · Responses",
         customMessages: "Custom · Messages",
diff --git a/openless-all/app/src/i18n/ja.ts b/openless-all/app/src/i18n/ja.ts
index b7ef1266..606c5b40 100644
--- a/openless-all/app/src/i18n/ja.ts
+++ b/openless-all/app/src/i18n/ja.ts
@@ -1012,6 +1012,7 @@ export const ja: typeof zhCN = {
         codingPlanX: 'CodingPlanX',
         minimax: 'MiniMax（M3）',
         stepfun: 'StepFun（階躍星辰）',
+        opencode: 'OpenCode Zen',
         customChatCompletions: "カスタム · Chat Completions",
         customResponses: "カスタム · Responses",
         customMessages: "カスタム · Messages",
diff --git a/openless-all/app/src/i18n/ko.ts b/openless-all/app/src/i18n/ko.ts
index fef89e75..0ffc6a58 100644
--- a/openless-all/app/src/i18n/ko.ts
+++ b/openless-all/app/src/i18n/ko.ts
@@ -1012,6 +1012,7 @@ export const ko: typeof zhCN = {
         codingPlanX: 'CodingPlanX',
         minimax: 'MiniMax (M3)',
         stepfun: 'StepFun',
+        opencode: 'OpenCode Zen',
         customChatCompletions: "사용자 지정 · Chat Completions",
         customResponses: "사용자 지정 · Responses",
         customMessages: "사용자 지정 · Messages",
diff --git a/openless-all/app/src/i18n/zh-CN.ts b/openless-all/app/src/i18n/zh-CN.ts
index 31d7d23d..b6d39c9c 100644
--- a/openless-all/app/src/i18n/zh-CN.ts
+++ b/openless-all/app/src/i18n/zh-CN.ts
@@ -1008,6 +1008,7 @@ export const zhCN = {
         codingPlanX: 'CodingPlanX',
         minimax: 'MiniMax（M3）',
         stepfun: 'StepFun（阶跃星辰）',
+        opencode: 'OpenCode Zen',
         customChatCompletions: "自定义 · Chat Completions",
         customResponses: "自定义 · Responses",
         customMessages: "自定义 · Messages",
diff --git a/openless-all/app/src/i18n/zh-TW.ts b/openless-all/app/src/i18n/zh-TW.ts
index 61e21257..1c7d5c84 100644
--- a/openless-all/app/src/i18n/zh-TW.ts
+++ b/openless-all/app/src/i18n/zh-TW.ts
@@ -1010,6 +1010,7 @@ export const zhTW: typeof zhCN = {
         codingPlanX: 'CodingPlanX',
         minimax: 'MiniMax（M3）',
         stepfun: 'StepFun（階躍星辰）',
+        opencode: 'OpenCode Zen',
         customChatCompletions: "自訂 · Chat Completions",
         customResponses: "自訂 · Responses",
         customMessages: "自訂 · Messages",
diff --git a/openless-all/app/src/lib/ipc/providers.ts b/openless-all/app/src/lib/ipc/providers.ts
index 2873b3b5..3db537eb 100644
--- a/openless-all/app/src/lib/ipc/providers.ts
+++ b/openless-all/app/src/lib/ipc/providers.ts
@@ -28,11 +28,14 @@ export interface ProviderDescriptor {
 /** Core owns protocol, defaults, and credential requirements. */
 export function listProviderDescriptors(kind: ProviderKind): Promise<ProviderDescriptor[]> {
   return invokeOrMock('list_provider_descriptors', { kind }, () => kind === 'llm' ? [
+    ['opencode', 'opencode', 'chat_completions'],
     ['custom', 'customChatCompletions', 'chat_completions'],
     ['custom_responses', 'customResponses', 'responses'],
     ['custom_messages', 'customMessages', 'messages'],
   ].map(([providerType, labelKey, format]) => ({
-    kind, providerType, labelKey, defaultEndpoint: null, defaultModel: null,
+    kind, providerType, labelKey,
+    defaultEndpoint: providerType === 'opencode' ? 'https://opencode.ai/zen/v1' : null,
+    defaultModel: providerType === 'opencode' ? 'deepseek-v4-flash' : null,
     authRequirement: 'api_key_unless_custom_endpoint', validationProbe: 'llm_text', staticModels: [],
     defaultRequestFormat: format as LlmRequestFormat,
     supportedRequestFormats: ['chat_completions', 'responses', 'messages'],
diff --git a/openless-all/app/src/pages/Overview.tsx b/openless-all/app/src/pages/Overview.tsx
index 95ba9168..6faee63a 100644
--- a/openless-all/app/src/pages/Overview.tsx
+++ b/openless-all/app/src/pages/Overview.tsx
@@ -52,6 +52,7 @@ const LLM_NAME_KEY_BY_ID: Record<string, string> = {
   openrouterFree: 'openrouterFree',
   alibabaCoding: 'alibabaCoding',
   codingPlanX: 'codingPlanX',
+  opencode: 'opencode',
   custom: 'custom',
 };
 
diff --git a/openless-all/app/src/pages/settings/LlmProtocolFields.test.ts b/openless-all/app/src/pages/settings/LlmProtocolFields.test.ts
index 9216eafd..f6192f9e 100644
--- a/openless-all/app/src/pages/settings/LlmProtocolFields.test.ts
+++ b/openless-all/app/src/pages/settings/LlmProtocolFields.test.ts
@@ -18,14 +18,27 @@ assert(protocolValidationError({ ...values, 'ark.messages_thinking': 'budget', '
 
 const descriptors = await listProviderDescriptors('llm');
 const presets = presetsFor('llm', 'win', true, undefined, descriptors);
-assert(presets.length === 3, 'Browser catalog should expose three compatibility presets');
+assert(presets.filter(p => p.id.startsWith('custom')).length === 3, 'Browser catalog should expose three compatibility presets');
+const opencode = presets.find(p => p.id === 'opencode');
+assert(opencode?.defaultRequestFormat === 'chat_completions'
+  && opencode.defaultEndpoint === 'https://opencode.ai/zen/v1'
+  && opencode.defaultModel === 'deepseek-v4-flash', 'OpenCode browser preset must retain Core defaults');
 assert(presets.find(p => p.id === 'custom_messages')?.defaultRequestFormat === 'messages', 'Picker must retain Core protocol defaults');
 for (const preset of presets) assert(preset.supportedRequestFormats?.length === 3, 'All compatibility presets allow switching');
 
-const first = await createChannel('llm', 'custom', 'first');
+const first = await createChannel('llm', 'opencode', 'first');
 const second = await createChannel('llm', 'custom', 'second');
 await setCredential('ark.request_format', 'messages', first);
 await setCredential('ark.api_key', 'fixture-key', first);
+await setCredential('ark.endpoint', 'https://opencode.ai/zen/go/v1', first);
+await setCredential('ark.model_id', 'deepseek-v4-flash', first);
+for (const format of ['chat_completions', 'responses', 'messages']) {
+  await setCredential('ark.request_format', format, first);
+  assert(await readCredential('ark.request_format', first) === format, 'OpenCode format must survive reload');
+  assert(await readCredential('ark.api_key', first) === 'fixture-key', 'Format changes preserve the key');
+  assert(await readCredential('ark.model_id', first) === 'deepseek-v4-flash', 'Format changes preserve the model');
+  assert(await readCredential('ark.endpoint', first) === 'https://opencode.ai/zen/go/v1', 'Format changes preserve the endpoint');
+}
 await recordChannelTest('llm', first, true, 1, null);
 await setCredential('ark.model_id', 'new-model', first);
 assert(await readCredential('ark.request_format', first) === 'messages', 'Changing model must preserve format');
diff --git a/openless-all/app/src/pages/settings/ProvidersSection.test.ts b/openless-all/app/src/pages/settings/ProvidersSection.test.ts
index 2668d8d4..7e027d7d 100644
--- a/openless-all/app/src/pages/settings/ProvidersSection.test.ts
+++ b/openless-all/app/src/pages/settings/ProvidersSection.test.ts
@@ -3,6 +3,9 @@ import { ASR_LABELS } from './shared';
 import { presetsFor } from './ChannelList';
 
 const atlascloudPreset = LLM_LABELS.find(p => p.id === 'atlascloud');
+if (LLM_LABELS.find(p => p.id === 'opencode')?.nameKey !== 'opencode') {
+  throw new Error('OpenCode LLM label is missing');
+}
 
 if (!atlascloudPreset) {
   throw new Error('Atlas Cloud LLM preset is missing');
diff --git a/openless-all/app/src/pages/settings/ProvidersSection.tsx b/openless-all/app/src/pages/settings/ProvidersSection.tsx
index bbc08e4c..f50e2e73 100644
--- a/openless-all/app/src/pages/settings/ProvidersSection.tsx
+++ b/openless-all/app/src/pages/settings/ProvidersSection.tsx
@@ -91,6 +91,7 @@ export const LLM_LABELS = [
   ['codex_oauth', 'codexOAuth'], ['mimo', 'mimo'], ['cometapi', 'cometapi'],
   ['openrouterFree', 'openrouterFree'], ['alibabaCoding', 'alibabaCoding'],
   ['codingPlanX', 'codingPlanX'], ['minimax', 'minimax'], ['stepfun', 'stepfun'],
+  ['opencode', 'opencode'],
   ['custom', 'customChatCompletions'], ['custom_responses', 'customResponses'], ['custom_messages', 'customMessages'],
 ].map(([id, nameKey]) => ({ id, nameKey })) as readonly { id: string; nameKey: string }[];