googleapis/mcp-toolbox · error

email not found in response: %v

Error message

email not found in response: %v

What it means

The decoded tokeninfo JSON contained no top-level `email` key — the credential's token does not carry an email identity (e.g. a token type without an associated user/service-account email).

Source

Thrown at internal/sources/util.go:117

	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)
	}

	fullEmail, ok := emailValue.(string)
	if !ok {
		return "", fmt.Errorf("email field is not a string")
	}

	var username string
	// Format the username based on Database Type
	switch strings.ToLower(dbType) {
	case "mysql":
		username, _, _ = strings.Cut(fullEmail, "@")

	case "postgres":
		// service account email used for IAM should trim the suffix
		username = strings.TrimSuffix(fullEmail, ".gserviceaccount.com")

	default:

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Use a credential that has an associated email (service account or user ADC)
2. Check the token type and scopes
3. Inspect the logged response JSON

When it happens

Trigger: Thrown at internal/sources/util.go:117 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/073756252f46d9b5. Report an issue: GitHub.