ZIm/docs/src/extensions/developing-extensions.md

Developing Extensions

Extension Capabilities

Extensions can add the following capabilities to Zed:

• Languages
• Themes

Directory Structure of a Zed Extension

A Zed extension is a Git repository that contains an extension.toml. This file must contain some basic information about the extension:

id = "my-extension"
name = "My extension"
version = "0.0.1"
schema_version = 1
authors = ["Your Name <you@example.com>"]
description = "My cool extension"
repository = "https://github.com/your-name/my-zed-extension"

In addition to this, there are several other optional files and directories that can be used to add functionality to a Zed extension. An example directory structure of an extension that provides all capabilities is as follows:

my-extension/
  extension.toml
  Cargo.toml
  src/
    lib.rs
  languages/
    config.toml
    highlights.scm
  themes/
    my-theme.json

WebAssembly

Procedural parts of extensions are written in Rust and compiled to WebAssembly. To develop an extension that includes custom code, include a Cargo.toml like this:

[package]
name = "my-extension"
version = "0.0.1"
edition = "2021"

[lib]
crate-type = ["cdylib"]

[dependencies]
zed_extension_api = "0.0.6"

Make sure to use the latest version of the zed_extension_api available on crates.io.

In the src/lib.rs file in your Rust crate you will need to define a struct for your extension and implement the Extension trait, as well as use the register_extension! macro to register your extension:

use zed_extension_api as zed;

struct MyExtension {
    // ... state
}

impl zed::Extension for MyExtension {
    // ...
}

zed::register_extension!(MyExtension);

Developing an Extension Locally

When developing an extension, you can use it in Zed without needing to publish it by installing it as a dev extension.

From the extensions page, click the Install Dev Extension button and select the directory containing your extension.

If you already have a published extension with the same name installed, your dev extension will override it.

Publishing your extension

To publish an extension, open a PR to this repo.

In your PR, do the following:

1. Add your extension as a Git submodule within the extensions/ directory
2. Add a new entry to the top-level extensions.toml file containing your extension:

[my-extension]
submodule = "extensions/my-extension"
version = "0.0.1"

3. Run pnpm sort-extensions to ensure extensions.toml and .gitmodules are sorted

Once your PR is merged, the extension will be packaged and published to the Zed extension registry.