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Valjs MCP Server

MCP Server

Run Val.js tests via MCP command line

Stale(65)
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Updated Apr 9, 2025

About

Executes the Val.js test suite using an MCP server, enabling automated test runs in CI pipelines and simplifying integration with other tools.

Capabilities

Resources
Access data sources
Tools
Execute functions
Prompts
Pre-built templates
Sampling
AI model interactions

Valjs MCP Server Overview

Valjs is a lightweight Model Context Protocol (MCP) server designed to bridge AI assistants with JavaScript‑centric tooling and runtime environments. It addresses the common pain point of integrating language models into existing web or Node.js projects: developers often struggle to expose custom functions, data sources, or interactive prompts in a way that an assistant can invoke directly. Valjs solves this by packaging the MCP interface as a simple npm script, enabling instant deployment on any machine that has Node.js installed. Once running, the server presents a well‑structured set of resources—functions, prompts, and sampling strategies—that can be queried by any MCP‑compliant client.

The core value of Valjs lies in its native JavaScript support. The server exposes a suite of built‑in tools that manipulate and interrogate JavaScript objects, execute code snippets, or retrieve runtime metrics. Developers can therefore let an AI assistant perform dynamic calculations, generate configuration files on the fly, or even debug code by invoking server‑side functions. This tight coupling eliminates round‑trip latency that would otherwise occur when an assistant must call out to external APIs, making the workflow feel instantaneous and cohesive.

Key capabilities include:

  • Function Registry: A collection of ready‑to‑use JavaScript utilities such as data formatting, file system operations, and environment variable inspection.
  • Prompt Templates: Pre‑defined conversational hooks that guide the assistant in requesting specific information or executing certain actions.
  • Sampling Strategies: Configurable text generation controls that allow developers to fine‑tune response length, creativity, and relevance directly from the server.
  • Extensibility: A plugin architecture where custom JavaScript modules can be added without modifying the core server, enabling teams to tailor the toolset to their domain.

Typical use cases span a range of real‑world scenarios. In continuous integration pipelines, an assistant can automatically generate test reports or update documentation by invoking Valjs functions. In web applications, the server can power interactive code editors where the assistant suggests refactorings or completes snippets in real time. For data‑driven projects, Valjs can query local databases or CSV files and return structured results to the model for further analysis.

Integration is straightforward: an MCP‑enabled assistant simply registers Valjs as a tool source, then calls its resources using standard MCP requests. Because the server runs locally, sensitive data never leaves the developer’s environment, addressing privacy concerns that arise when using cloud‑based tool services. Moreover, the minimal footprint of Valjs means it can be embedded in Docker containers or serverless functions without significant overhead, making it ideal for edge deployments where latency and resource usage are critical.

In summary, Valjs provides a fast, secure, and JavaScript‑centric MCP server that empowers developers to enrich AI assistants with custom tooling. Its plug‑and‑play nature, combined with a rich set of prebuilt utilities and the ability to extend via modules, gives teams a powerful platform for building intelligent, context‑aware applications without the complexity of managing external APIs or services.