Dynamic MCP server selection with OpenAI GPT-4.1 and contextual AI reranker

PROBLEM Thousands of MCP Servers exist and many are updated daily, making server selection difficult for LLMs. - Current approaches require manually downloading and configuring servers, limiting flexibility. - When multiple servers are pre-configured, LLMs get overwhelmed and confused about which server to use for specific tasks.

This template enables dynamic server selection from a live PulseMCP directory of 5000+ servers.

How it works - A user query goes to an LLM that decides whether to use MCP servers to fulfill a given query and provides reasoning for its decision. - Next, we fetch MCP Servers from Pulse MCP API and format them as documents for reranking - Now, we use Contextual AI's Reranker to score and rank all MCP Servers based on our query and instructions

How to set up - Sign up for a free trial of Contextual AI [here](https://app.contextual.ai/) to find CONTEXTUALAIAPIKEY. - Click on variables option in left panel and add a new environment variable CONTEXTUALAIAPIKEY. - For the baseline model, we have used GPT 4.1 mini, you can find your OpenAI API key[ here](https://platform.openai.com/api-keys)

How to customize the workflow - We use chat trigger to initate the workflow. Feel free to replace it with a webhook or other trigger as required. - We use OpenAI's GPT 4.1 mini as the baseline model and reranker prompt generator. You can swap out this section to use the LLM of your choice. - We fetch 5000 MCP Servers from the PulseMCP directory as a baseline number, feel free to adjust this parameter as required. - We are using Contextual AI's ctxl-rerank-v2-instruct-multilingual reranker model, which can be swapped with any one of the following rerankers: 1) ctxl-rerank-v2-instruct-multilingual 2) ctxl-rerank-v2-instruct-multilingual-mini 3) ctxl-rerank-v1-instruct - You can checkout this [blog](https://contextual.ai/blog/context-engineering-for-your-mcp-client/) for more information about rerankers to learn more about them.

Good to know: - Contextual AI Reranker (with full MCP docs): ~$0.035/query Includes 0.035 for reranking + ~$0.0001 for OpenAI instruction generation. - OpenAI Baseline: ~$0.017/query