nexus mcp search/add — Smithery-backed MCP registry with multi-tool projection

[canoo]

Problem

Installing an MCP server requires manually editing a separate config file for each AI tool. A developer using Claude Code, Cursor, and Kiro has to add the same server to three different JSON files in different locations. This is the most-cited MCP pain point in the developer community.

Research confirms Smithery.ai has become the de-facto human-facing MCP registry with 12,000+ servers, while registry.modelcontextprotocol.io is the programmatic authority (r/smithery, April 2026). Neither solves the multi-tool installation problem.

Solution

nexus mcp add <name> installs an MCP server from Smithery/official registry and projects the config entry to every installed tool in one command.

$ nexus mcp add github

Fetching github from Smithery... found charmbracelet/mcp-github v1.2.0
Installing to ~/.config/nexus/mcp/github/

Projecting to installed tools:
  ✓ Claude Code  → ~/.claude.json
  ✓ Cursor       → ~/.cursor/mcp.json
  ✓ Kiro         → ~/.kiro/mcp.json
  ✓ Windsurf     → ~/.codeium/windsurf/mcp_config.json

Done. Restart your AI tools to activate.

Commands

nexus mcp search <query>    # search Smithery API
nexus mcp add <name>        # install + project to all tools
nexus mcp remove <name>     # uninstall + remove from all tool configs
nexus mcp list              # show installed servers and status per tool

Curated defaults

A short NEXUS-recommended list installs with one command: nexus mcp add --recommended

Recommended set: github, cloudflare, filesystem, postgres, jira, linear

Sources

• Smithery API: https://smithery.ai
• Official MCP registry: https://registry.modelcontextprotocol.io
• Multi-tool MCP pain: r/ClaudeCode, r/cursor, April 2026

Dependencies

Requires #17 (driver system, to know each tool's MCP config location) and #81 (nexus sync).