googleapis/mcp-toolbox · error

failed to create BigQuery v2 service: %w

Error message

failed to create BigQuery v2 service: %w

What it means

This error is thrown when the low-level BigQuery REST service (google.golang.org/api/bigquery/v2) fails to initialize via bigqueryrestapi.NewService using the same client options as the high-level client. The toolbox builds both a high-level bigquery.Client and a raw REST service; failure here means the REST layer could not be created even though the high-level client succeeded. Wrapped causes are usually option validation or transport setup failures.

Source

Thrown at internal/sources/bigquery/bigquery.go:825

	if endpoint != "" {
		opts = append(opts, option.WithEndpoint(endpoint))
	}
	if quotaProject != "" {
		opts = append(opts, option.WithQuotaProject(quotaProject))
	}

	// Initialize the high-level BigQuery client
	client, err := bigqueryapi.NewClient(ctx, project, opts...)
	if err != nil {
		return nil, nil, nil, fmt.Errorf("failed to create BigQuery client for project %q: %w", project, err)
	}
	client.Location = location

	// Initialize the low-level BigQuery REST service using the same credentials
	restService, err := bigqueryrestapi.NewService(ctx, opts...)
	if err != nil {
		return nil, nil, nil, fmt.Errorf("failed to create BigQuery v2 service: %w", err)
	}

	return client, restService, tokenSource, nil
}

// initBigQueryConnectionWithOAuthToken initialize a BigQuery client with an
// OAuth access token.
func initBigQueryConnectionWithOAuthToken(
	ctx context.Context,
	tracer trace.Tracer,
	project string,
	location string,
	quotaProject string,
	name string,
	userAgent string,
	tokenString string,
	wantRestService bool,
	endpoint string,

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Inspect the wrapped error with errors.As/Unwrap to identify the exact cause.
2. Verify any custom endpoint/base-URL option is a valid BigQuery v2 API URL.
3. Ensure only one credential mechanism (token source or credentials) is applied consistently.
4. Check network/proxy access to bigquery.googleapis.com and retry if transient.

Example fix

// before
opts := []option.ClientOption{
  option.WithUserAgent(userAgent),
  option.WithTokenSource(ts),
  option.WithCredentials(cred), // conflicting credential options
}
// after
opts := []option.ClientOption{
  option.WithUserAgent(userAgent),
  option.WithTokenSource(ts), // single credential mechanism
}

// Validate connectivity to the BigQuery v2 endpoint first
resp, err := http.Get("https://bigquery.googleapis.com/")
if err != nil {
  return fmt.Errorf("BigQuery API endpoint unreachable: %w", err)
}
resp.Body.Close()

// Go
client, rest, ts, err := initBigQueryConnection(ctx, cfg)
if err != nil && strings.Contains(err.Error(), "failed to create BigQuery v2 service") {
  // transient? retry once with backoff before failing startup
  time.Sleep(2 * time.Second)
  client, rest, ts, err = initBigQueryConnection(ctx, cfg)
  if err != nil {
    log.Fatalf("BigQuery v2 REST service init failed: %v — check endpoint/proxy and credential options", err)
  }
}

When it happens

Trigger: bigqueryrestapi.NewService(ctx, opts...) returns an error while constructing the REST client from the same opts (user agent, token source/credentials, quota project) — e.g. invalid option combination, failure resolving the API endpoint, or transport/credentials setup errors inside the google-api-go-client.

Common situations: Custom base URL / endpoint misconfiguration; proxy or firewall interfering with API endpoint resolution; incompatible or conflicting option.WithTokenSource plus option.WithCredentials values; intermittent transport errors during service construction.

Related errors

• failed to create BigQuery client for project %q: %w
• failed to verify allowedDataset '%s' in project '%s': %w
• error creating client from OAuth access token: %w
• unable to iterate through query results: %w
• failed to insert dry run job: %w

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/f38fadca13233342. Report an issue: GitHub.