usebruno/bruno · error · Error

Failed to create client

Error message

Failed to create client

What it means

Defensive guard after constructing a gRPC client via makeGenericClientConstructor({}). The constructor essentially always returns a client instance, so this branch is effectively dead code; if hit, it indicates the grpc-js factory returned null/undefined for an internal reason.

Source

Thrown at packages/bruno-requests/src/grpc/grpc-client.js:666

    // Extract user-agent from headers if provided (case-insensitive)
    // Set it as grpc.primary_user_agent channel option to prepend to the default user-agent
    const userAgentKey = Object.keys(request.headers).find(
      (key) => key.toLowerCase() === 'user-agent'
    );
    const userAgentValue = userAgentKey ? request.headers[userAgentKey] : null;

    // Resolve proxy target and channel options
    const { targetHost, proxyChannelOptions } = this.#resolveProxyTarget(host, proxyConfig);

    const mergedChannelOptions = { ...channelOptions, ...proxyChannelOptions };
    if (userAgentValue && !channelOptions?.['grpc.primary_user_agent']) {
      mergedChannelOptions['grpc.primary_user_agent'] = userAgentValue;
    }

    const Client = makeGenericClientConstructor({});
    const client = new Client(targetHost, credentials, mergedChannelOptions);
    if (!client) {
      throw new Error('Failed to create client');
    }

    let messages = request.body.grpc;
    try {
      messages = messages.map(({ content }) => safeJsonParse(content, 'message content'));
    } catch (parseError) {
      console.error('Failed to parse gRPC message content:', parseError);
      client.close();
      this.eventCallback('grpc:error', request.uid, collection.uid, {
        error: parseError
      });
      return; // Exit early to prevent sending invalid data
    }

    const requestPath = path + methodPath;
    const requestId = request.uid;
    const collectionUid = collection.uid;
    const metadata = new Metadata();

View on GitHub (pinned to 9bdd81c7bd)

Solutions

1. Treat as an internal invariant violation: reinstall node_modules and ensure @grpc/grpc-js is a supported version.
2. If seen in tests, check that makeGenericClientConstructor is not mocked to return undefined.

const client = new Client(targetHost, credentials, mergedChannelOptions);
if (!client || typeof client.makeUnaryRequest !== 'function') throw new Error('Failed to create client');

When it happens

Trigger: makeGenericClientConstructor returned a falsy value when invoked with an empty service definition object, which under normal grpc-js operation does not occur.

Common situations: Practically unreachable. Theoretically a broken grpc-js build, a monkeypatched global, or a stubbed makeGenericClientConstructor in tests could trigger it.

Related errors

• Invalid collection format: ${format}
• Failed to parse ${context}: ${error.message}
• Method ${path} not found, please refresh the methods
• Unsupported method type: ${methodType}
• Failed to refresh methods and method ${methodPath} not found

AI-assisted analysis of usebruno/bruno@9bdd81c7bd (2026-08-13). Data as JSON: /api/errors/a255a152e88b03f7. Report an issue: GitHub.