router-for-me/CLIProxyAPI · error

antigravity token exchange: decode response: %w

Error message

antigravity token exchange: decode response: %w

What it means

The token exchange returned 2xx but the response body is not decodable as a TokenResponse JSON (access_token/refresh_token fields). Causes: empty body despite 200, HTML/HTML-fragment body, or a schema where the token fields are nested differently.

Source

Thrown at internal/auth/antigravity/auth.go:176

			log.Errorf("antigravity token exchange: close body error: %v", errClose)
		}
	}()

	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
		bodyBytes, errRead := io.ReadAll(io.LimitReader(resp.Body, 8<<10))
		if errRead != nil {
			return nil, fmt.Errorf("antigravity token exchange: read response: %w", errRead)
		}
		body := strings.TrimSpace(string(bodyBytes))
		if body == "" {
			return nil, fmt.Errorf("antigravity token exchange: request failed: status %d", resp.StatusCode)
		}
		return nil, fmt.Errorf("antigravity token exchange: request failed: status %d: %s", resp.StatusCode, body)
	}

	var token TokenResponse
	if errDecode := json.NewDecoder(resp.Body).Decode(&token); errDecode != nil {
		return nil, fmt.Errorf("antigravity token exchange: decode response: %w", errDecode)
	}
	return &token, nil
}

// FetchUserInfo retrieves user email from Google
func (o *AntigravityAuth) FetchUserInfo(ctx context.Context, accessToken string) (string, error) {
	accessToken = strings.TrimSpace(accessToken)
	if accessToken == "" {
		return "", fmt.Errorf("antigravity userinfo: missing access token")
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, UserInfoEndpoint, nil)
	if err != nil {
		return "", fmt.Errorf("antigravity userinfo: create request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+accessToken)
	req.Header.Set("User-Agent", o.shortUserAgent())

	resp, errDo := o.httpClient.Do(req)

View on GitHub (pinned to 78f0c4079e)

Solutions

1. Log the raw body (redacting tokens) when decode fails to see what was actually returned
2. If a proxy intercepted the response, bypass it or trust its CA and retry with a fresh code
3. If the schema changed, update TokenResponse fields/json tags

var typeErr *json.UnmarshalTypeError
if errors.As(err, &typeErr) {
	// schema drift: token JSON shape changed
} else if strings.Contains(err.Error(), "decode response") {
	// interception or truncation — retry with a fresh code
}

When it happens

Trigger: A proxy returns 200 with an auth-page body; upstream changes token response shape; body truncated by a read timeout mid-decode.

Common situations: Captive portals / proxy interception on the token endpoint; partial responses on flaky links.

Related errors

• antigravity userinfo: decode response: %w
• antigravity token exchange: read response: %w
• antigravity userinfo: read response: %w
• marshal request body: %w
• antigravity token exchange: create request: %w

AI-assisted analysis of router-for-me/CLIProxyAPI@78f0c4079e (2026-08-15). Data as JSON: /api/errors/dcf4110b8152b6d5. Report an issue: GitHub.