googleapis/mcp-toolbox · error

error reading response body %d: %s

Error message

error reading response body %d: %s

What it means

io.ReadAll failed while reading the tokeninfo response body — the response stream was interrupted mid-read (connection reset or truncation).

Source

Thrown at internal/sources/util.go:101

// GetIAMPrincipalEmailFromADC finds the email associated with ADC
func GetIAMPrincipalEmailFromADC(ctx context.Context, dbType string) (string, error) {
	// Finds ADC and returns an HTTP client associated with it
	client, err := google.DefaultClient(ctx,
		"https://www.googleapis.com/auth/userinfo.email")
	if err != nil {
		return "", fmt.Errorf("failed to call userinfo endpoint: %w", err)
	}

	// Retrieve the email associated with the token
	resp, err := client.Get("https://oauth2.googleapis.com/tokeninfo")
	if err != nil {
		return "", fmt.Errorf("failed to call tokeninfo endpoint: %w", err)
	}
	defer resp.Body.Close()

	bodyBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("error reading response body %d: %s", resp.StatusCode, string(bodyBytes))
	}
	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("tokeninfo endpoint returned non-OK status %d: %s", resp.StatusCode, string(bodyBytes))
	}

	// Unmarshal response body and get `email`
	var responseJSON map[string]any
	err = json.Unmarshal(bodyBytes, &responseJSON)
	if err != nil {

		return "", fmt.Errorf("error parsing JSON: %v", err)
	}

	emailValue, ok := responseJSON["email"]
	if !ok {
		return "", fmt.Errorf("email not found in response: %v", err)
	}

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Retry the lookup on transient network interruptions
2. Check network stability to Google endpoints
3. Inspect the status code included in the message

When it happens

Trigger: Thrown at internal/sources/util.go:101 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/47de7571e9871b6e. Report an issue: GitHub.