Synapse
Synapse is a small second-brain demo on Symfony AI 1.0 beta, and it is also a tutorial series: five parts, each one a branch of the tutorial repository, published step by step. A capture agent files raw text into an inbox or, when it is clear knowledge, into a folder of Open Knowledge Format notes; every file access goes through one small Vault class that decides which paths exist. A read agent answers from the notes with RAG. The brain is then exposed as an MCP server with symfony/mcp-bundle behind an external authorization server, with read and write roles mapped to Symfony roles, and in the last step one instance asks a second brain over MCP while a Cohere reranker ranks both answers together. It runs on symfony/ai-agent, the AI Bundle, the MCP SDK and Cohere. The submitted repository is the optimised and improved result of the series; the step-by-step version lives in the tutorial repository.