diff --git a/internal/openai/eino_http.go b/internal/openai/eino_http.go
index 7c2a8bc5..a4d761e0 100644
--- a/internal/openai/eino_http.go
+++ b/internal/openai/eino_http.go
@@ -6,7 +6,8 @@ import (
 	"cyberstrike-ai/internal/config"
 )
 
-// NewEinoHTTPClient adds OpenAI-compatible request fixes and SSE sanitation.
+// NewEinoHTTPClient adds OpenAI-compatible request fixes, SSE error decoding,
+// and successful-stream heartbeat sanitation.
 // Claude channels use Eino's native agenticclaude model and never enter here.
 func NewEinoHTTPClient(cfg *config.OpenAIConfig, base *http.Client) *http.Client {
 	if base == nil {
@@ -18,6 +19,7 @@ func NewEinoHTTPClient(cfg *config.OpenAIConfig, base *http.Client) *http.Client
 		transport = http.DefaultTransport
 	}
 	transport = &reasoningToolChoiceCompatRoundTripper{base: transport, cfg: cfg}
+	transport = &einoSSEErrorRoundTripper{base: transport}
 	transport = &einoSSESanitizingRoundTripper{base: transport}
 	cloned.Transport = transport
 	return &cloned
diff --git a/internal/openai/eino_sse_error.go b/internal/openai/eino_sse_error.go
new file mode 100644
index 00000000..5437cada
--- /dev/null
+++ b/internal/openai/eino_sse_error.go
@@ -0,0 +1,94 @@
+package openai
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"strconv"
+)
+
+const einoSSEErrorMaxBytes = 64 * 1024
+
+// Some gateways send SSE even for HTTP errors (occasionally labeled JSON).
+// The SDK decodes non-2xx responses as JSON. Unwrap only a validated error
+// event, preserving HTTP status and error fields for retry classification.
+type einoSSEErrorRoundTripper struct {
+	base http.RoundTripper
+}
+
+func (rt *einoSSEErrorRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := rt.base.RoundTrip(req)
+	if err != nil || resp == nil || resp.Body == nil || resp.StatusCode < 400 {
+		return resp, err
+	}
+	upstream := resp.Body
+	body, readErr := io.ReadAll(io.LimitReader(upstream, einoSSEErrorMaxBytes+1))
+	// Replay all consumed bytes and any read failure if normalization is unsafe.
+	readers := []io.Reader{bytes.NewReader(body)}
+	if readErr != nil {
+		readers = append(readers, sseErrorReadFailure{readErr})
+	}
+	readers = append(readers, upstream)
+	resp.Body = &sseErrorReplayBody{Reader: io.MultiReader(readers...), Closer: upstream}
+	if readErr != nil || len(body) > einoSSEErrorMaxBytes {
+		return resp, nil
+	}
+	payload := extractSSEError(body)
+	if payload == nil {
+		return resp, nil
+	}
+	resp.Body = &sseErrorReplayBody{Reader: bytes.NewReader(payload), Closer: upstream}
+	resp.Header = resp.Header.Clone()
+	if resp.Header == nil {
+		resp.Header = make(http.Header)
+	}
+	resp.Header.Set("Content-Type", "application/json")
+	resp.Header.Set("Content-Length", strconv.Itoa(len(payload)))
+	resp.Header.Del("Transfer-Encoding")
+	resp.ContentLength = int64(len(payload))
+	resp.TransferEncoding = nil
+	return resp, nil
+}
+
+type sseErrorReplayBody struct {
+	io.Reader
+	io.Closer
+}
+
+type sseErrorReadFailure struct{ err error }
+
+func (r sseErrorReadFailure) Read([]byte) (int, error) { return 0, r.err }
+
+// Honor SSE event boundaries and multiline data. Unknown/plain/invalid bodies
+// are left intact, rather than replacing useful diagnostics with guesses.
+func extractSSEError(body []byte) []byte {
+	var data []byte
+	validate := func() []byte {
+		var envelope struct {
+			Error *struct {
+				Message json.RawMessage `json:"message"`
+			} `json:"error"`
+		}
+		if json.Unmarshal(data, &envelope) == nil && envelope.Error != nil && len(envelope.Error.Message) > 0 && !bytes.Equal(envelope.Error.Message, []byte("null")) {
+			return bytes.TrimSpace(data)
+		}
+		return nil
+	}
+	for _, line := range bytes.Split(body, []byte("\n")) {
+		line = bytes.TrimSuffix(line, []byte("\r"))
+		if len(line) == 0 {
+			if payload := validate(); payload != nil {
+				return payload
+			}
+			data = nil
+			continue
+		}
+		if bytes.HasPrefix(line, []byte("data:")) {
+			value := bytes.TrimPrefix(line[5:], []byte(" "))
+			data = append(data, value...)
+			data = append(data, '\n')
+		}
+	}
+	return validate() // Gateways sometimes omit the final blank line.
+}
diff --git a/internal/openai/eino_sse_error_test.go b/internal/openai/eino_sse_error_test.go
new file mode 100644
index 00000000..1673fbb7
--- /dev/null
+++ b/internal/openai/eino_sse_error_test.go
@@ -0,0 +1,112 @@
+package openai
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	einoopenai "github.com/cloudwego/eino-ext/components/model/openai"
+	"github.com/cloudwego/eino/schema"
+)
+
+func TestSSEErrorThroughEinoModel(t *testing.T) {
+	for _, status := range []int{400, 429, 503} {
+		for _, ct := range []string{"text/event-stream", "application/json", ""} {
+			t.Run(http.StatusText(status)+"/"+ct, func(t *testing.T) {
+				srv := newSSEServer(t, `data:{"error":{"code":"400","message":"Invalid request parameters","param":"tool_choice","type":"BadRequestError"}}`, ct, status)
+				defer srv.Close()
+				m, err := einoopenai.NewChatModel(context.Background(), &einoopenai.ChatModelConfig{APIKey: "local-test", BaseURL: srv.URL, Model: "local-test", HTTPClient: NewEinoHTTPClient(nil, srv.Client())})
+				if err != nil {
+					t.Fatal(err)
+				}
+				_, err = m.Stream(context.Background(), []*schema.Message{schema.UserMessage("test")})
+				var apiErr *einoopenai.APIError
+				if !errors.As(err, &apiErr) {
+					t.Fatalf("expected structured API error, got %v", err)
+				}
+				if apiErr.HTTPStatusCode != status || apiErr.Message != "Invalid request parameters" || apiErr.Type != "BadRequestError" || apiErr.Code != "400" || apiErr.Param == nil || *apiErr.Param != "tool_choice" {
+					t.Fatalf("error fields changed: %+v", apiErr)
+				}
+			})
+		}
+	}
+}
+
+func TestSSEErrorBodyCompatibility(t *testing.T) {
+	payload := `{"error":{"message":"rejected","extra":"preserved"}}`
+	for _, tc := range []struct {
+		name, body, want string
+		status           int
+	}{
+		{"plain JSON", payload, payload, 400},
+		{"HTML", "<html>bad gateway</html>", "<html>bad gateway</html>", 502},
+		{"malformed", "data:{broken}", "data:{broken}", 400},
+		{"not error", "data:{\"choices\":[]}", "data:{\"choices\":[]}", 400},
+		{"null error", "data:{\"error\":null}", "data:{\"error\":null}", 400},
+		{"SSE", "data:" + payload, payload, 400},
+		{"CRLF heartbeat", ": ping\r\nevent: error\r\ndata: " + payload + "\r\n\r\ndata: [DONE]\r\n", payload, 400},
+		{"multiline", "data: {\"error\":\ndata: {\"message\":\"rejected\",\"extra\":\"preserved\"}}\n\n", "{\"error\":\n{\"message\":\"rejected\",\"extra\":\"preserved\"}}", 400},
+		{"success", "data:" + payload, "data:" + payload, 200},
+		{"oversized", "data:" + payload + strings.Repeat(" ", einoSSEErrorMaxBytes), "data:" + payload + strings.Repeat(" ", einoSSEErrorMaxBytes), 400},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			srv := newSSEServer(t, tc.body, "text/event-stream", tc.status)
+			defer srv.Close()
+			client := &http.Client{Transport: &einoSSEErrorRoundTripper{base: http.DefaultTransport}}
+			resp, err := client.Get(srv.URL)
+			if err != nil {
+				t.Fatal(err)
+			}
+			got := readAll(t, resp.Body)
+			if got != tc.want {
+				t.Fatalf("body differs: got %q want %q", got, tc.want)
+			}
+			if resp.StatusCode != tc.status {
+				t.Fatal("status changed")
+			}
+			if tc.want != tc.body && (resp.Header.Get("Content-Type") != "application/json" || resp.ContentLength != int64(len(got))) {
+				t.Fatal("incorrect normalized headers")
+			}
+		})
+	}
+}
+
+type errorResponseTransport struct{ body io.ReadCloser }
+
+func (rt errorResponseTransport) RoundTrip(*http.Request) (*http.Response, error) {
+	return &http.Response{StatusCode: 400, Header: http.Header{"X-Request-Id": []string{"test-id"}}, Body: rt.body}, nil
+}
+
+type failingErrorBody struct {
+	closed bool
+	err    error
+}
+
+func (b *failingErrorBody) Read(p []byte) (int, error) {
+	return copy(p, `data:{"error":{"message":"partial"}}`), b.err
+}
+func (b *failingErrorBody) Close() error { b.closed = true; return nil }
+func TestSSEErrorPreservesReadFailureAndClose(t *testing.T) {
+	sentinel := errors.New("upstream disconnected")
+	body := &failingErrorBody{err: sentinel}
+	rt := &einoSSEErrorRoundTripper{base: errorResponseTransport{body: body}}
+	req, _ := http.NewRequest("GET", "http://local.test", nil)
+	resp, err := rt.RoundTrip(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := io.ReadAll(resp.Body)
+	if !errors.Is(err, sentinel) || string(got) != `data:{"error":{"message":"partial"}}` {
+		t.Fatalf("read failure lost: %q %v", got, err)
+	}
+	if resp.Header.Get("X-Request-Id") != "test-id" {
+		t.Fatal("request ID lost")
+	}
+	resp.Body.Close()
+	if !body.closed {
+		t.Fatal("upstream not closed")
+	}
+}
diff --git a/internal/openai/eino_sse_sanitizer.go b/internal/openai/eino_sse_sanitizer.go
index 43e07d5b..340b3a04 100644
--- a/internal/openai/eino_sse_sanitizer.go
+++ b/internal/openai/eino_sse_sanitizer.go
@@ -54,7 +54,7 @@ func (rt *einoSSESanitizingRoundTripper) RoundTrip(req *http.Request) (*http.Res
 }
 
 // isSSEResponse 仅对 200 + text/event-stream 的响应做清洗;
-// 错误响应 (4xx/5xx 通常是 application/json) 不动, 由 SDK 走原错误路径。
+// 错误响应由独立的 einoSSEErrorRoundTripper 处理，此层不改动。
 func isSSEResponse(resp *http.Response) bool {
 	if resp.StatusCode != http.StatusOK {
 		return false