Nexus Aims to Deliver an Open Source AI Router for MCP Servers and Large Language Models

Developers Fredrik Björk and Julius de Bruijn have launched an open source project for artificial intelligence routing — picking the right model for the right job, while also serving as an aggregator for multiple Model Context Protocol (MCP) servers: Nexus.

"As AI applications become more sophisticated, they increasingly need to interact with multiple external services, APIs, and different language models," the pair explains of the problem the Nexus project set out to solve. "This creates several pain points: context, helps the LLM select from a potentially large number of MCP tools without overwhelming it; cost, lack of strategic model selection can lead to unnecessary expenses; observability, provides insights into the performance and behavior of the AI system, enabling better decision-making and troubleshooting; [and] security, ensures that requests are routed securely and in compliance with governance policies."

Nexus looks to fix these problems by offering automated routing of queries to different large language models (LLMs) — taking into account different models' performance at different tasks, the latency between prompt and response, context window lengths, and availability. This, the pair say, will be enhanced in the future to include more advanced routing algorithms, support for custom rules and policies, and real-time monitoring.

The software also serves a second purpose: acting as a proxy between "agentic" AI and the Model Context Protocol (MCP) servers which give them their capabilities. A single request to Nexus, the developers say, will be automatically routed to the most appropriate MCP server for the task - complete with authentication and connection management, and the ability to aggregate responses from multiple sources if required.

"The future of AI applications lies in intelligent orchestration," Björk and de Bruijn claim, "and Nexus is our contribution to making that future more accessible and efficient for developers everywhere."

Nexus is available, including its source code, on GitHub under the Mozilla Public License Version 2.0; more information is available on the project website.