Cadence (FlowIndex)

Bringing Cadence, the resource-oriented smart contract language of Flow, to your VSCode Editor.

Installation

Install the Cadence extension from the Visual Studio Marketplace

The extension is also available on the Open VSX Registry

Once installed, the extension uses the bundled Cadence LSP v2 by default. The Flow CLI is still useful for debugging and CLI-driven workflows, but it is no longer required just to get language features.

Features

Cadence Language Server

The Cadence extension provides a language server for Cadence. The language server is responsible for providing language features like code completion, diagnostics, and more. The default server is the bundled Cadence LSP v2, managed independently from Flow CLI so editor improvements can ship faster.

Debugging

Use the debugger build into VSCode on Cadence files by creating a launch.json file. Make sure to have an emulator connected to enable debugging.

Example launch.json

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "cadence",
      "request": "launch",
      "name": "Curent file",
      "program": "${file}",
      "stopOnEntry": true
    }
  ]
}

But wait, there's much more than meets the eye. VSCode Cadence extension also offers:

• Syntax highlighting (including in Markdown code fences)
• Diagnostics (errors and warnings)
• Code completion, including documentation
• Type information on hover
• Go to declaration
• Go to symbol
• Document outline
• Renaming
• Signature help
• Symbol highlighting
• Code actions
• Declare constants, variables, functions, fields, and methods
• Add missing members when implementing an interface
• Apply removal suggestion
• Apply replacement suggestion
• Flow.json schema validation