diff --git a/src-tauri/src/proxy/forwarder.rs b/src-tauri/src/proxy/forwarder.rs
index 48f2af19f..c60470dbb 100644
--- a/src-tauri/src/proxy/forwarder.rs
+++ b/src-tauri/src/proxy/forwarder.rs
@@ -790,6 +790,13 @@ impl RequestForwarder {
             == Some("github_copilot")
             || base_url.contains("githubcopilot.com");
 
+        if is_copilot {
+            mapped_body =
+                super::providers::copilot_model_map::apply_copilot_model_normalization(mapped_body);
+            self.apply_copilot_live_model_resolution(provider, &mut mapped_body)
+                .await;
+        }
+
         // --- Copilot 优化器：分类 + 请求体优化（在格式转换之前执行） ---
         // 注意：确定性 ID 也在此处计算，因为 mapped_body 在格式转换时会被 move
         //
@@ -1485,6 +1492,49 @@ impl RequestForwarder {
         "openai_chat".to_string()
     }
 
+    /// 用 Copilot live `/models` 列表确认 model ID 真实可用，找不到时按 family 降级。
+    /// 命中缓存后是同步的；首次请求或 5 min 缓存过期后会触发一次 HTTP。
+    async fn apply_copilot_live_model_resolution(
+        &self,
+        provider: &Provider,
+        body: &mut serde_json::Value,
+    ) {
+        let Some(model_id) = body.get("model").and_then(|v| v.as_str()) else {
+            return;
+        };
+        let model_id = model_id.to_string();
+
+        let Some(app_handle) = &self.app_handle else {
+            return;
+        };
+        let copilot_state = app_handle.state::<CopilotAuthState>();
+        let copilot_auth = copilot_state.0.read().await;
+        let account_id = provider
+            .meta
+            .as_ref()
+            .and_then(|m| m.managed_account_id_for("github_copilot"));
+
+        let models_result = match account_id.as_deref() {
+            Some(id) => copilot_auth.fetch_models_for_account(id).await,
+            None => copilot_auth.fetch_models().await,
+        };
+
+        let models = match models_result {
+            Ok(m) => m,
+            Err(err) => {
+                log::debug!("[Copilot] live model list unavailable, skip resolution: {err}");
+                return;
+            }
+        };
+
+        if let Some(resolved) =
+            super::providers::copilot_model_map::resolve_against_models(&model_id, &models)
+        {
+            log::info!("[Copilot] live-model resolve: {model_id} → {resolved}");
+            body["model"] = serde_json::Value::String(resolved);
+        }
+    }
+
     async fn is_copilot_openai_vendor_model(&self, provider: &Provider, model_id: &str) -> bool {
         let Some(app_handle) = &self.app_handle else {
             log::debug!("[Copilot] AppHandle unavailable, fallback to chat/completions");
diff --git a/src-tauri/src/proxy/providers/copilot_model_map.rs b/src-tauri/src/proxy/providers/copilot_model_map.rs
new file mode 100644
index 000000000..e4ca4355d
--- /dev/null
+++ b/src-tauri/src/proxy/providers/copilot_model_map.rs
@@ -0,0 +1,374 @@
+//! GitHub Copilot 模型 ID 归一化与 live-list 解析
+//!
+//! Copilot upstream 仅接受 dot 形式的 Claude 4.x 模型 ID（如 `claude-sonnet-4.6`），
+//! 而 Claude Code 客户端发出 dash 形式（如 `claude-sonnet-4-6`、`claude-sonnet-4-6[1m]`）。
+//! 不归一化会触发上游 400 `model_not_supported`。
+//!
+//! 仅做语法归一化不够：账号订阅级别可能不开放某个具体模型。
+//! `resolve_against_models` 用 `/models` live 列表做精确匹配，找不到时
+//! 按 family（haiku/sonnet/opus）+ 最高版本号 fallback。
+
+use super::copilot_auth::CopilotModel;
+use serde_json::Value;
+
+/// 归一化客户端 model ID 为 Copilot upstream 接受的形式。
+/// 返回 `None` 表示无需变换（已归一化、非 Claude 4.x 系列、或空输入）。
+pub(super) fn normalize_to_copilot_id(client_id: &str) -> Option<String> {
+    let trimmed = client_id.trim();
+    let bytes = trimmed.as_bytes();
+
+    if bytes.len() < 8 || !bytes[..7].eq_ignore_ascii_case(b"claude-") {
+        return None;
+    }
+
+    let has_one_m_bracket = ends_with_ascii_ci(bytes, b"[1m]");
+
+    // Fast path: 已含点 + 不带 [1m] → 已归一化（绝大多数请求走这里）
+    if trimmed.contains('.') && !has_one_m_bracket {
+        return None;
+    }
+
+    let (base, has_1m_suffix) = split_one_m_suffix(trimmed);
+    let stripped = strip_trailing_date(base);
+    let dotted = dashes_to_dot_in_last_version(stripped);
+
+    if dotted.is_none() && !has_1m_suffix {
+        return None;
+    }
+
+    let mut candidate = dotted.unwrap_or_else(|| stripped.to_string());
+    if has_1m_suffix {
+        candidate.push_str("-1m");
+    }
+    (candidate != trimmed).then_some(candidate)
+}
+
+/// 在请求体中应用 model ID 归一化。
+pub fn apply_copilot_model_normalization(mut body: Value) -> Value {
+    let Some(orig) = body.get("model").and_then(|v| v.as_str()) else {
+        return body;
+    };
+    if let Some(normalized) = normalize_to_copilot_id(orig) {
+        log::debug!("[CopilotNormalizer] {orig} → {normalized}");
+        body["model"] = Value::String(normalized);
+    }
+    body
+}
+
+fn ends_with_ascii_ci(haystack: &[u8], needle: &[u8]) -> bool {
+    haystack.len() >= needle.len()
+        && haystack[haystack.len() - needle.len()..].eq_ignore_ascii_case(needle)
+}
+
+fn split_one_m_suffix(id: &str) -> (&str, bool) {
+    let bytes = id.as_bytes();
+    if ends_with_ascii_ci(bytes, b"[1m]") {
+        return (&id[..bytes.len() - 4], true);
+    }
+    if ends_with_ascii_ci(bytes, b"-1m") {
+        return (&id[..bytes.len() - 3], true);
+    }
+    (id, false)
+}
+
+fn strip_trailing_date(id: &str) -> &str {
+    let Some(last_dash) = id.rfind('-') else {
+        return id;
+    };
+    let suffix = &id[last_dash + 1..];
+    if suffix.len() == 8 && suffix.bytes().all(|b| b.is_ascii_digit()) {
+        &id[..last_dash]
+    } else {
+        id
+    }
+}
+
+/// 把 `…-X-Y`（X、Y 都是纯数字的末两段）变成 `…-X.Y`。
+/// 返回 `None` 表示模式不匹配（保守策略避免误伤 `claude-3-5-sonnet` 等历史 ID）。
+fn dashes_to_dot_in_last_version(id: &str) -> Option<String> {
+    let last_dash = id.rfind('-')?;
+    let last_segment = &id[last_dash + 1..];
+    if last_segment.is_empty() || !last_segment.bytes().all(|b| b.is_ascii_digit()) {
+        return None;
+    }
+    let head = &id[..last_dash];
+    let prev_dash = head.rfind('-')?;
+    let prev_segment = &head[prev_dash + 1..];
+    if prev_segment.is_empty() || !prev_segment.bytes().all(|b| b.is_ascii_digit()) {
+        return None;
+    }
+    Some(format!("{head}.{last_segment}"))
+}
+
+/// 用 Copilot live 模型列表确认/降级 model ID。
+///
+/// 流程：
+/// 1. 先做语法归一化（dash→dot、`[1m]`→`-1m`）
+/// 2. 在 `models` 中精确匹配；找到则使用归一化后的 ID
+/// 3. 找不到时按 family（haiku/sonnet/opus）取最高版本号 fallback
+///    （优先保留 `-1m` 标志；都没有则取 base 版）
+///
+/// 返回 `None` 表示无需变换或无可降级的 family 候选（保留原 ID 让上游决定，
+/// 让用户拿到明确的 `model_not_supported` 而非被静默替换）。
+pub fn resolve_against_models(client_id: &str, models: &[CopilotModel]) -> Option<String> {
+    let normalized = normalize_to_copilot_id(client_id);
+    let target = normalized.as_deref().unwrap_or(client_id);
+
+    if models.iter().any(|m| m.id.eq_ignore_ascii_case(target)) {
+        return normalized.filter(|s| s != client_id);
+    }
+
+    let fallback = family_fallback(target, models)?;
+    if fallback.eq_ignore_ascii_case(client_id) {
+        None
+    } else {
+        Some(fallback)
+    }
+}
+
+fn detect_family(id: &str) -> Option<&'static str> {
+    let lower = id.to_ascii_lowercase();
+    if lower.contains("haiku") {
+        Some("haiku")
+    } else if lower.contains("sonnet") {
+        Some("sonnet")
+    } else if lower.contains("opus") {
+        Some("opus")
+    } else {
+        None
+    }
+}
+
+/// 提取 family 后第一段 `MAJOR.MINOR` 版本号。
+/// 例：`claude-sonnet-4.6` → (4, 6)；`claude-sonnet-4.6-1m` → (4, 6)。
+fn extract_major_minor(id: &str) -> Option<(u32, u32)> {
+    let lower = id.to_ascii_lowercase();
+    let family = detect_family(&lower)?;
+    let after = &lower[lower.find(family)? + family.len()..];
+    let after = after.strip_prefix('-')?;
+    let segment = after.split(['-', '[', ' ']).next()?;
+    let mut parts = segment.split('.');
+    let major: u32 = parts.next()?.parse().ok()?;
+    let minor: u32 = parts.next().unwrap_or("0").parse().ok()?;
+    Some((major, minor))
+}
+
+fn family_fallback(target: &str, models: &[CopilotModel]) -> Option<String> {
+    let family = detect_family(target)?;
+    let want_1m = target.ends_with("-1m");
+
+    let pick_best = |require_1m: bool| -> Option<String> {
+        models
+            .iter()
+            .filter(|m| {
+                let lower = m.id.to_ascii_lowercase();
+                lower.contains(family) && lower.ends_with("-1m") == require_1m
+            })
+            .filter_map(|m| extract_major_minor(&m.id).map(|v| (m, v)))
+            .max_by_key(|(_, v)| *v)
+            .map(|(m, _)| m.id.clone())
+    };
+
+    if want_1m {
+        pick_best(true).or_else(|| pick_best(false))
+    } else {
+        pick_best(false)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn dashes_to_dot_basic() {
+        assert_eq!(
+            normalize_to_copilot_id("claude-sonnet-4-6"),
+            Some("claude-sonnet-4.6".to_string())
+        );
+        assert_eq!(
+            normalize_to_copilot_id("claude-opus-4-6"),
+            Some("claude-opus-4.6".to_string())
+        );
+        assert_eq!(
+            normalize_to_copilot_id("claude-haiku-4-5"),
+            Some("claude-haiku-4.5".to_string())
+        );
+    }
+
+    #[test]
+    fn one_m_bracket_to_dash() {
+        assert_eq!(
+            normalize_to_copilot_id("claude-sonnet-4-6[1m]"),
+            Some("claude-sonnet-4.6-1m".to_string())
+        );
+        assert_eq!(
+            normalize_to_copilot_id("claude-opus-4-6[1m]"),
+            Some("claude-opus-4.6-1m".to_string())
+        );
+    }
+
+    #[test]
+    fn one_m_bracket_on_already_dotted() {
+        // claude-sonnet-4.6[1m] 走非 fast-path 分支（has_one_m_bracket=true），
+        // 应被改写为 -1m 形式
+        assert_eq!(
+            normalize_to_copilot_id("claude-sonnet-4.6[1m]"),
+            Some("claude-sonnet-4.6-1m".to_string())
+        );
+    }
+
+    #[test]
+    fn date_suffix_stripped() {
+        assert_eq!(
+            normalize_to_copilot_id("claude-haiku-4-5-20251001"),
+            Some("claude-haiku-4.5".to_string())
+        );
+        assert_eq!(
+            normalize_to_copilot_id("claude-sonnet-4-5-20250929"),
+            Some("claude-sonnet-4.5".to_string())
+        );
+    }
+
+    #[test]
+    fn already_copilot_format_returns_none() {
+        assert_eq!(normalize_to_copilot_id("claude-sonnet-4.6"), None);
+        assert_eq!(normalize_to_copilot_id("claude-opus-4.6-1m"), None);
+        assert_eq!(normalize_to_copilot_id("claude-haiku-4.5"), None);
+    }
+
+    #[test]
+    fn non_claude_models_untouched() {
+        assert_eq!(normalize_to_copilot_id("gpt-5"), None);
+        assert_eq!(normalize_to_copilot_id("gpt-4o-mini"), None);
+        assert_eq!(normalize_to_copilot_id("o3"), None);
+        assert_eq!(normalize_to_copilot_id(""), None);
+    }
+
+    #[test]
+    fn legacy_three_part_versions_untouched() {
+        assert_eq!(normalize_to_copilot_id("claude-3-5-sonnet"), None);
+        assert_eq!(normalize_to_copilot_id("claude-3-5-sonnet-20241022"), None);
+    }
+
+    #[test]
+    fn case_insensitive_on_prefix_and_suffix() {
+        assert_eq!(
+            normalize_to_copilot_id("Claude-Sonnet-4-6"),
+            Some("Claude-Sonnet-4.6".to_string())
+        );
+        assert_eq!(
+            normalize_to_copilot_id("claude-sonnet-4-6[1M]"),
+            Some("claude-sonnet-4.6-1m".to_string())
+        );
+    }
+
+    #[test]
+    fn bracket_one_m_with_date_combined() {
+        assert_eq!(
+            normalize_to_copilot_id("claude-haiku-4-5-20251001[1m]"),
+            Some("claude-haiku-4.5-1m".to_string())
+        );
+    }
+
+    #[test]
+    fn apply_rewrites_body() {
+        let body = json!({"model": "claude-sonnet-4-6", "max_tokens": 1024});
+        let out = apply_copilot_model_normalization(body);
+        assert_eq!(out["model"], "claude-sonnet-4.6");
+        assert_eq!(out["max_tokens"], 1024);
+    }
+
+    #[test]
+    fn apply_no_change_when_already_normalized() {
+        let body = json!({"model": "claude-sonnet-4.6"});
+        let out = apply_copilot_model_normalization(body);
+        assert_eq!(out["model"], "claude-sonnet-4.6");
+    }
+
+    #[test]
+    fn apply_handles_missing_model() {
+        let body = json!({"messages": []});
+        let out = apply_copilot_model_normalization(body);
+        assert!(out.get("model").is_none());
+    }
+
+    fn model(id: &str) -> CopilotModel {
+        CopilotModel {
+            id: id.to_string(),
+            name: id.to_string(),
+            vendor: "anthropic".to_string(),
+            model_picker_enabled: true,
+        }
+    }
+
+    #[test]
+    fn resolve_exact_match_after_normalize() {
+        let models = vec![
+            model("claude-sonnet-4.6"),
+            model("claude-opus-4.6"),
+            model("claude-haiku-4.5"),
+        ];
+        assert_eq!(
+            resolve_against_models("claude-sonnet-4-6", &models),
+            Some("claude-sonnet-4.6".to_string())
+        );
+    }
+
+    #[test]
+    fn resolve_returns_none_when_already_valid() {
+        let models = vec![model("claude-sonnet-4.6")];
+        assert_eq!(resolve_against_models("claude-sonnet-4.6", &models), None);
+    }
+
+    #[test]
+    fn resolve_falls_back_to_highest_family_version() {
+        // 用户请求 opus 4.7 但 Copilot 账号只有 opus 4.6
+        let models = vec![
+            model("claude-opus-4.5"),
+            model("claude-opus-4.6"),
+            model("claude-sonnet-4.6"),
+        ];
+        assert_eq!(
+            resolve_against_models("claude-opus-4.7", &models),
+            Some("claude-opus-4.6".to_string())
+        );
+    }
+
+    #[test]
+    fn resolve_prefers_1m_when_requested() {
+        let models = vec![
+            model("claude-sonnet-4.6"),
+            model("claude-sonnet-4.6-1m"),
+            model("claude-opus-4.6"),
+        ];
+        assert_eq!(
+            resolve_against_models("claude-sonnet-4-6[1m]", &models),
+            Some("claude-sonnet-4.6-1m".to_string())
+        );
+    }
+
+    #[test]
+    fn resolve_falls_back_to_base_when_1m_unavailable() {
+        // 账号没开 -1m 变体时降级到 base
+        let models = vec![model("claude-sonnet-4.6")];
+        assert_eq!(
+            resolve_against_models("claude-sonnet-4-6[1m]", &models),
+            Some("claude-sonnet-4.6".to_string())
+        );
+    }
+
+    #[test]
+    fn resolve_returns_none_when_family_absent() {
+        // 账号完全没有 opus 时不做强行替换，让上游报错
+        let models = vec![model("claude-sonnet-4.6"), model("claude-haiku-4.5")];
+        assert_eq!(resolve_against_models("claude-opus-4.6", &models), None);
+    }
+
+    #[test]
+    fn resolve_handles_non_claude_target() {
+        let models = vec![model("claude-sonnet-4.6")];
+        assert_eq!(resolve_against_models("gpt-5", &models), None);
+    }
+}
diff --git a/src-tauri/src/proxy/providers/mod.rs b/src-tauri/src/proxy/providers/mod.rs
index 94475555b..ec98d462f 100644
--- a/src-tauri/src/proxy/providers/mod.rs
+++ b/src-tauri/src/proxy/providers/mod.rs
@@ -17,6 +17,7 @@ mod claude;
 mod codex;
 pub mod codex_oauth_auth;
 pub mod copilot_auth;
+pub mod copilot_model_map;
 mod gemini;
 pub(crate) mod gemini_schema;
 pub mod gemini_shadow;
diff --git a/src/config/claudeProviderPresets.ts b/src/config/claudeProviderPresets.ts
index ec0143659..a67d5e66b 100644
--- a/src/config/claudeProviderPresets.ts
+++ b/src/config/claudeProviderPresets.ts
@@ -809,10 +809,10 @@ export const providerPresets: ProviderPreset[] = [
     settingsConfig: {
       env: {
         ANTHROPIC_BASE_URL: "https://api.githubcopilot.com",
-        ANTHROPIC_MODEL: "claude-opus-4.7",
+        ANTHROPIC_MODEL: "claude-sonnet-4.6",
         ANTHROPIC_DEFAULT_HAIKU_MODEL: "claude-haiku-4.5",
         ANTHROPIC_DEFAULT_SONNET_MODEL: "claude-sonnet-4.6",
-        ANTHROPIC_DEFAULT_OPUS_MODEL: "claude-opus-4.7",
+        ANTHROPIC_DEFAULT_OPUS_MODEL: "claude-sonnet-4.6",
       },
     },
     category: "third_party",