googleapis/mcp-toolbox · error

error parsing JSON: %v

Error message

error parsing JSON: %v

What it means

json.Unmarshal failed to decode the tokeninfo response body into a map — the endpoint returned a body that is not valid JSON, despite the 200 status.

Source

Thrown at internal/sources/util.go:112

	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)
	}

	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, "@")

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Retry after transient malformed responses
2. Log and inspect the raw body bytes
3. Report if the endpoint consistently returns non-JSON

When it happens

Trigger: Thrown at internal/sources/util.go:112 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/8f029c4715bbb2cb. Report an issue: GitHub.