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Axel

Editor setup

Editor setup

Section titled “Editor setup”

Axel ships editor extensions for Zed and VS Code. Each provides syntax highlighting plus a language server — live diagnostics, hover, go-to-definition, and completion — for .asl schemas and .aql queries.

Prerequisites

Section titled “Prerequisites”

The language server is the axel CLI (axel lsp), so both editors need axel installed and on your PATH. Install it first (see Installation) and verify:

Terminal window
axel version

If axel isn’t found, syntax highlighting still works, but the language-server features won’t start (the extension shows a “not found” notice).

Both extensions live in the Axel repo under tools/, so clone it:

Terminal window
git clone https://github.com/struckchure/axel.git
cd axel

Zed

Section titled “Zed”

Zed installs the extension from a local directory as a dev extension and compiles it on install: the tree-sitter grammars and the Rust language-server shim. You need a Rust toolchain (Zed adds the wasm target itself).

  1. Open the command palette (cmd-shift-p) and run zed: install dev extension.
  2. Select the tools/zed directory in your Axel checkout.
  3. Open a .asl or .aql file — highlighting and LSP features activate automatically.

To use a specific axel binary instead of the one on PATH, add to your Zed settings.json:

{ "lsp": { "axel": { "binary": { "path": "/absolute/path/to/axel" } } } }

More detail: tools/zed/README.md.

VS Code

Section titled “VS Code”

Build a .vsix and install it with the code CLI. Requires Bun.

Terminal window
cd tools/vscode
bun install
bun run package                     # produces axel-<version>.vsix
code --install-extension axel-*.vsix

Reload VS Code, then open a .asl or .aql file.

To use a specific axel binary, set it in Settings (axel.path):

{ "axel.path": "/absolute/path/to/axel" }

Developing the extension: open the tools/vscode folder in VS Code and press F5 to launch an Extension Development Host with the extension loaded; after editing the source, re-run bun run package and reinstall. Use the Axel: Restart Language Server command to reconnect after installing or updating axel.

More detail: tools/vscode/README.md.

What you get

Section titled “What you get”
  • Syntax highlighting for .asl and .aql.
  • Diagnostics — live parse/resolve errors for schemas, and parse/compile errors for queries.
  • Hover, go-to-definition, and completion, powered by axel lsp (including full IntelliSense and documentation for AQL built-in directives @name, @request, @response, @rel_load_strategy, and schema directives).
  • Configuration autocomplete & validation in axel.yaml via YAML language server schema integration (# yaml-language-server: $schema=...).

Query files are resolved against your schema via axel.yaml (schema-path) in the workspace root, so completion and cross-file diagnostics know your types.

When schema-path is a directory or a glob, the language server merges the whole split schema before resolving it: a type declared in one file is known in every other, and a problem is reported against the file that owns it.