fix(proxy): improve GitHub Copilot compatibility with modern Claude Code (#5832)

* 修复 Copilot 与新版 Claude Code 的兼容问题

* docs(proxy): correct Copilot placeholder rationale to the real mechanism

Claude Code (verified on 2.1.220) does not format-validate ANTHROPIC_API_KEY
against sk-ant-*: in headless mode the placeholder is sent upstream as-is.
The actual failure mode is the interactive custom-API-key approval prompt,
which defaults to "No (recommended)" — following the default ignores the
key and lands users in "Not logged in". Also drop the #3289 citation,
which describes a missing-placeholder scenario, not key validation.

---------

Co-authored-by: Jason <farion1231@gmail.com>

src-tauri/src/provider.rs

@@ -87,6 +87,17 @@ impl Provider {
             || self.claude_base_url_contains("chatgpt.com/backend-api/codex")
     }
 
+    /// Whether the provider form's "auth field" was explicitly set to
+    /// ANTHROPIC_API_KEY. The form only persists `meta.apiKeyField` for the
+    /// non-default choice, so `None` means the default ANTHROPIC_AUTH_TOKEN.
+    pub fn claude_uses_api_key_field(&self) -> bool {
+        self.meta
+            .as_ref()
+            .and_then(|m| m.api_key_field.as_deref())
+            .map(|field| field.eq_ignore_ascii_case("ANTHROPIC_API_KEY"))
+            .unwrap_or(false)
+    }
+
     fn provider_type(&self) -> Option<&str> {
         self.meta.as_ref().and_then(|m| m.provider_type.as_deref())
     }

src-tauri/src/proxy/forwarder.rs

@@ -1183,6 +1183,15 @@ impl RequestForwarder {
                 super::providers::copilot_model_map::apply_copilot_model_normalization(mapped_body);
             self.apply_copilot_live_model_resolution(provider, &mut mapped_body)
                 .await;
+            // Strip the [1M] context marker after Copilot normalization/resolve.
+            // A user's mapped value (e.g. "gpt-5.6-sol[1M]") carries [1M] as a
+            // Claude Code context-capability declaration that upstream APIs reject
+            // as part of the model name. The preceding normalization step already
+            // rewrites claude-xxx[1M] into the "-1m" dash form Copilot accepts, and
+            // the strip helper only touches the "[1m]" bracket form, so "-1m"
+            // variants pass through unchanged.
+            mapped_body =
+                super::model_mapper::strip_one_m_suffix_for_upstream_from_body(mapped_body);
         } else if !codex_responses_to_anthropic {
             // Skip on the Codex→Anthropic path: stripping [1m] here would break both the
             // model-catalog match (apply_codex_upstream_model) and the transform's own

src-tauri/src/services/proxy.rs

@@ -95,9 +95,16 @@ impl ProxyService {
         let auth_policy = if provider.uses_managed_account_auth() {
             // Codex 系（含仅凭 base_url 识别、无 provider_type meta 的）必须保留
             // ANTHROPIC_AUTH_TOKEN 占位符：Claude Code 缺该键会弹登录提示（#3784）。
-            // Copilot 维持仅 API_KEY 占位，避免与 /login 管理的 key 冲突（#1049）。
+            // Copilot 默认同样注入 AUTH_TOKEN 占位符：Claude Code（实测 2.1.220）
+            // 对 ANTHROPIC_API_KEY 会弹"是否使用该自定义 key"确认框且默认
+            // "No (recommended)"，按默认走后占位符被忽略、落入 Not logged in
+            // （并非 sk-ant-* 格式校验——headless 下占位符原样出站）；AUTH_TOKEN
+            // 作为网关 Bearer 被直接信任，零弹窗。仅当供应商表单显式选择了
+            // ANTHROPIC_API_KEY（meta.apiKeyField）时才保留 API_KEY 占位，以规避
+            // 与 /login 管理的 key 冲突（#1049）。
             ClaudeTakeoverAuthPolicy::ManagedAccount {
-                keep_auth_token: !provider.is_github_copilot(),
+                keep_auth_token: !provider.is_github_copilot()
+                    || !provider.claude_uses_api_key_field(),
             }
         } else {
             ClaudeTakeoverAuthPolicy::PreserveExistingOrAuthToken
@@ -197,7 +204,10 @@ impl ProxyService {
                 // - Codex 系保留 AUTH_TOKEN：缺该键 Claude Code 会弹登录提示（#3784）。
                 //   无条件注入而非"已存在才保留"：热切换路径传入的是 provider
                 //   settings（预设不含该键），且旧版接管已把存量用户 live 中的键删光。
-                // - Copilot 仅 API_KEY：避免与 /login 管理的 key 冲突（#1049）。
+                // - Copilot 默认 AUTH_TOKEN：API_KEY 占位符会触发 Claude Code 的
+                //   自定义 key 确认框（默认 "No (recommended)"），按默认走即
+                //   Not logged in；仅当表单显式选择了 ANTHROPIC_API_KEY 时才用
+                //   API_KEY 占位以规避 /login key 冲突（#1049）。
                 if keep_auth_token {
                     env.insert(
                         "ANTHROPIC_AUTH_TOKEN".to_string(),
@@ -3304,7 +3314,7 @@ mod tests {
     }
 
     #[test]
-    fn managed_account_claude_takeover_uses_api_key_placeholder() {
+    fn managed_account_claude_takeover_uses_auth_token_placeholder() {
         let mut provider = Provider::with_id(
             "copilot".to_string(),
             "GitHub Copilot".to_string(),
@@ -3333,13 +3343,13 @@ mod tests {
             .and_then(|value| value.as_object())
             .expect("env should exist");
         assert_eq!(
-            env.get("ANTHROPIC_API_KEY")
+            env.get("ANTHROPIC_AUTH_TOKEN")
                 .and_then(|value| value.as_str()),
             Some(PROXY_TOKEN_PLACEHOLDER)
         );
         assert!(
-            env.get("ANTHROPIC_AUTH_TOKEN").is_none(),
+            env.get("ANTHROPIC_API_KEY").is_none(),
-            "managed OAuth providers should avoid Claude Auth Token login semantics"
+            "API_KEY placeholders trigger Claude Code's custom-key approval prompt (defaults to No), landing users in Not logged in"
         );
     }
 
@@ -3421,8 +3431,8 @@ mod tests {
             "CLAUDE_CODE_SUBAGENT_MODEL",
             Some("claude-sonnet-4.6[1M]"),
         );
-        assert_env_str(env, "ANTHROPIC_API_KEY", Some(PROXY_TOKEN_PLACEHOLDER));
+        assert_env_str(env, "ANTHROPIC_AUTH_TOKEN", Some(PROXY_TOKEN_PLACEHOLDER));
-        assert_env_str(env, "ANTHROPIC_AUTH_TOKEN", None);
+        assert_env_str(env, "ANTHROPIC_API_KEY", None);
     }
 
     #[test]
@@ -3675,7 +3685,7 @@ mod tests {
     }
 
     #[test]
-    fn managed_account_claude_takeover_copilot_removes_stale_auth_token() {
+    fn managed_account_claude_takeover_copilot_defaults_to_auth_token() {
         let mut provider = Provider::with_id(
             "copilot".to_string(),
             "GitHub Copilot".to_string(),
@@ -3691,6 +3701,48 @@ mod tests {
             ..Default::default()
         });
 
+        let mut live_config = json!({
+            "env": {
+                "ANTHROPIC_BASE_URL": "https://stale.example.com",
+                "ANTHROPIC_AUTH_TOKEN": "stale-token",
+                "ANTHROPIC_API_KEY": "stale-key"
+            }
+        });
+        ProxyService::apply_claude_takeover_fields_for_provider(
+            &mut live_config,
+            "http://127.0.0.1:15721",
+            &provider,
+        );
+
+        let env = live_config
+            .get("env")
+            .and_then(|value| value.as_object())
+            .expect("env should exist");
+        // Default Copilot takeover injects AUTH_TOKEN: the API_KEY placeholder
+        // triggers Claude Code's custom-key approval prompt (defaults to
+        // "No (recommended)"), which lands users in "Not logged in".
+        assert_env_str(env, "ANTHROPIC_AUTH_TOKEN", Some(PROXY_TOKEN_PLACEHOLDER));
+        assert_env_str(env, "ANTHROPIC_API_KEY", None);
+    }
+
+    #[test]
+    fn managed_account_claude_takeover_copilot_honors_api_key_field_choice() {
+        let mut provider = Provider::with_id(
+            "copilot".to_string(),
+            "GitHub Copilot".to_string(),
+            json!({
+                "env": {
+                    "ANTHROPIC_BASE_URL": "https://api.githubcopilot.com"
+                }
+            }),
+            None,
+        );
+        provider.meta = Some(ProviderMeta {
+            provider_type: Some("github_copilot".to_string()),
+            api_key_field: Some("ANTHROPIC_API_KEY".to_string()),
+            ..Default::default()
+        });
+
         let mut live_config = json!({
             "env": {
                 "ANTHROPIC_BASE_URL": "https://stale.example.com",
@@ -3707,6 +3759,8 @@ mod tests {
             .get("env")
             .and_then(|value| value.as_object())
             .expect("env should exist");
+        // Explicit API-key-field choice keeps the API_KEY placeholder to avoid
+        // conflicting with the /login-managed key (#1049).
         assert_env_str(env, "ANTHROPIC_API_KEY", Some(PROXY_TOKEN_PLACEHOLDER));
         assert_env_str(env, "ANTHROPIC_AUTH_TOKEN", None);
     }