Build CLIs
agents can use.

See Crust in action

1. convert.tsTypeScript

   import { Crust } from "@crustjs/core";
   
   const convert = new Crust("convert")
   	.args({ name: "input", type: "string", required: true })
   	.flags({ name: "to", type: "string", default: "html" })
   	.action(({ args, flags, stdout }) => {
   		stdout(`Converting ${args.input} as ${flags.to}`);
   	});
   
   await convert.execute();

   BunNode.jsDeno

   bun run convert.ts report.mdConverting report.md as html bun run convert.ts report.md --to pdfConverting report.md as pdf

2. serve.tsTypeScript

   import { Crust } from "@crustjs/core";
   import { z } from "zod";
   
   const Port = z.coerce.number().max(65535).default(3000);
   
   const serve = new Crust("serve")
   	.args({ name: "port", schema: Port })
   	.action(({ args, stdout }) => {
   		stdout(`listening on port ${args.port}`);
   	});
   
   await serve.execute();

   BunNode.jsDeno

   bun run serve.tslistening on port 3000 bun run serve.ts 70000Error: Invalid input:  - args.port: Too big: expected number to be <=65535

3. work.tsTypeScript

   import { Crust, defineContext } from "@crustjs/core";
   
   const db = defineContext("db").setup(
   	({ stdout, defer }) => {
   		stdout("db opened");
   		defer(() => stdout("db closed"));
   		return { query: (sql: string) => `${sql}: ok` };
   	},
   );
   
   const work = new Crust("work")
   	.provide(db())
   	.command("query", (command) =>
   		command.action(async ({ ctx, stdout }) => {
   			stdout((await ctx.db).query("select 1"));
   		}),
   	)
   	.command("fail", (command) =>
   		command.action(async ({ ctx }) => {
   			await ctx.db;
   			throw new Error("query failed");
   		}),
   	);
   
   await work.execute();

   BunNode.jsDeno

   bun run work.ts querydb openedselect 1: okdb closed bun run work.ts faildb openeddb closed Error: query failed

4. deploy.tsTypeScript

   import {
   	Crust,
   	defineExtension,
   	defineExtensionId,
   } from "@crustjs/core";
   
   const id = defineExtensionId("acme:preview");
   const preview = defineExtension(id)
   	.flags({ name: "preview", type: "boolean" })
   	.preRun((ctx) => {
   		if (ctx.flags.preview !== true) return;
   		ctx.stdout("nothing changed");
   		return ctx.handled();
   	});
   
   const deploy = new Crust("deploy")
   	.extend(preview)
   	.action(({ stdout }) => stdout("deployed"));
   
   await deploy.execute();

   BunNode.jsDeno

   bun run deploy.tsdeployed bun run deploy.ts --previewnothing changed

5. cli.test.tsTypeScript

   import { Crust } from "@crustjs/core";
   import { captureExecute } from "@crustjs/testing";
   
   const app = new Crust("cli").command("greet", (command) =>
   	command.action(({ stdout }) => stdout("Hello")),
   );
   
   const captured = await captureExecute(app, ["unknown"]);
   console.log(captured.exitCode);
   console.log(captured.stderr);
   

   BunNode.jsDeno

   bun run cli.test.ts1Error: Unknown command "unknown".

6. package.jsonJSON

   {
     "name": "my-cli",
     "version": "1.2.3",
     "bin": {
       "my-cli": "src/cli.ts"
     },
     "crust": {
       "runtime": "bun",
       "artifact": "binary"
     },
     "scripts": {
       "build": "crust build",
       "release": "crust publish"
     }
   }

   BunNode.jsDeno

   crust build --target bun-linux-x64.crust/├── manifest.json├── root/bin/my-cli.js└── linux-x64/bin/my-cli-bun-linux-x64

7. src/cli.tsTypeScript

   import { Crust, defineCommand } from "@crustjs/core";
   import { help } from "@crustjs/extensions";
   import { skill } from "@crustjs/skills";
   
   const deploy = defineCommand(
   	"deploy",
   	{ description: "Deploy the app" },
   	(command) => command.action(() => {}),
   );
   
   const app = new Crust("my-cli", {
   	description: "Manage deployments",
   	version: "1.2.3",
   })
   	.extend(help()) // --help for humans
   	.extend(skill({})) // SKILL.md for agents
   	.add(deploy);
   
   await app.execute();

   BunNode.jsDeno

   crust build  # stages the skill help listsbun run src/cli.ts --helpmy-cli - Manage deployments Usage:  my-cli <command> [options] Commands:  deploy     Deploy the app  skills (skill) Manage agent skill installations (shorthand for `install`) Options:  -h, --help                   Show help Agent skills:  my-cli — Manage deployments    Source: .crust/root/skills/my-cli

8. src/cli.tsTypeScript

   import { Crust, defineCommand } from "@crustjs/core";
   import { help } from "@crustjs/extensions";
   import { skill } from "@crustjs/skills";
   
   const deploy = defineCommand(
   	"deploy",
   	{ description: "Deploy the app" },
   	(command) => command.action(() => {}),
   );
   
   const app = new Crust("my-cli", {
   	description: "Manage deployments",
   	version: "1.2.3",
   })
   	.extend(help()) // --help for humans
   	.extend(skill({})) // SKILL.md for agents
   	.add(deploy);
   
   await app.execute();

   BunNode.jsDeno

   crust build.crust/artifacts/skills/my-cli/├── SKILL.md└── commands/    ├── my-cli.md    ├── deploy.md    ├── skills.md    └── skills/        ├── install.md        ├── repair.md        └── uninstall.md