Guides: Editors and coding agents: See each problem as you type, in VS Code, Neovim or another editor, and give a coding agent the result of each change. # Editors and coding agents > See each problem as you type, in VS Code, Neovim or another editor, and give a coding agent the result of each change. This guide shows archangel’s problems in your editor while you type, and gives a coding agent the result of each change it makes. ## Before you start * Install archangel in the repository: `npm install --save-dev @enhance-eng/archangel`. * The repository has an archangel config. ## The language server `archangel lsp` is a language server on standard input and output. Your editor starts it for you. * When the editor starts, it shows the problems of a full check. * It follows the text that you type, before you save. * It offers each fix that archangel has checked as a quick fix. * It finds the config as the command line does: the nearest config at or above the folder that the editor opened. ## Set up your editor * VS Code The Archangel extension for VS Code is in the archangel repository, in [`editors/vscode`](https://github.com/enhance-labs-builds/archangel/tree/main/editors/vscode). It is not on the Marketplace yet. To run it from a clone of the repository: 1. Build the extension: ```sh cd editors/vscode npm ci npm run bundle ``` 2. Start VS Code with the extension, and open your repository: ```sh code --extensionDevelopmentPath="$PWD" /path/to/your/repository ``` The extension starts in a workspace whose folder has an archangel config. It runs the first archangel that it finds: 1. the `archangel.path` setting; 2. the workspace’s `node_modules/.bin/archangel`; 3. `archangel` on `PATH`, for example after `cargo install archangel`. The **Archangel** output channel says which one it runs. If it finds none, it shows an error that names the three places. Install archangel, then run **Archangel: Restart Server**. In a workspace with more than one folder, the extension checks the first folder. * Neovim Neovim 0.11 and later start a language server from a config. Put this in `init.lua`: ```lua vim.lsp.config('archangel', { cmd = { 'npx', 'archangel', 'lsp' }, filetypes = { 'typescript', 'typescriptreact', 'javascript', 'javascriptreact' }, root_markers = { 'archangel.config.ts', 'archangel.config.mts', 'archangel.config.js', 'archangel.config.mjs', 'archangel.config.json', }, }) vim.lsp.enable('archangel') ``` If you installed archangel with Cargo, use `cmd = { 'archangel', 'lsp' }`. * Zed Zed starts a language server only through an extension, and archangel has no Zed extension yet. Run `npx archangel watch` in Zed’s terminal. After each save, it prints each problem that is new and each problem that is gone. * Other editors Each editor that can start a language server can run archangel. Configure the command `npx archangel lsp`, for the file types TypeScript and JavaScript, with or without JSX. Use a folder that holds an archangel config as the root. ## Coding agents A coding agent writes code faster than a person reviews it. If it does not know your architecture, it adds the import that makes its task work. Give it the check while it writes, not ten minutes later in CI. 1. Start watch mode beside the agent, with JSON output: ```sh npx archangel watch --format json ``` 2. Tell the agent to read the last line after each edit, and to fix each new problem before it moves on. Each check prints one line, a JSON document with these keys: | Key | What it holds | | --------------- | ----------------------------------------------------------------------------------------------------------------------------------------- | | `schemaVersion` | The version of this format, now `1`. | | `new` | The problems that this check found and the last check did not. | | `gone` | The problems of the last check that this check did not find. | | `summary` | The counts of files, imports and problems, the exceptions and baseline entries for each rule, the work that the check did, and `polling`. | The first line lists each problem as new. Each problem has its `code`, `rule`, `file`, `line`, `column`, `message`, `help` and `reason`, as in `archangel check --format json`. When the system has no file watches left, archangel polls the files. Each summary then says so in `polling`. Tell the agent what to run Put the commands in the instructions file of your agent, for example `AGENTS.md`: run `npx archangel check` before a task is done, and `npx archangel explain :` to see why an import is refused. An agent can also run single commands: * `npx archangel check src/features/cart/index.ts` shows only the problems of one file. It still checks the whole repository, because a cycle depends on all files. * `npx archangel explain ` shows the part, the rules and the imports of a file. * `npx archangel why ` shows the shortest chain of imports between two points. ## Next steps * [Use archangel in CI](/archangel/guides/ci/). * [Commands](/archangel/reference/commands/).