Creating Zed Extensions

Overview

Zed extensions are Rust programs compiled to WebAssembly that can provide slash commands, language support, themes, grammars, and MCP servers. Extensions implement the zed::Extension trait and are distributed via Zed's extension registry.

When to Use

Create a Zed extension when:

• Adding custom slash commands to the Assistant (/deploy, /analyze, /fetch-docs)
• Providing language support (syntax highlighting, LSP, formatting)
• Creating custom color themes
• Integrating external tools via slash commands
• Providing MCP server integrations

Don't create for:

• Simple rules or instructions (use .rules files)
• One-time scripts (use terminal)
• Project-specific configuration (use .zed/settings.json)