GitHub – vercel-labs/just-bash: エージェント用の Bash

挨拶.txt’); const result = await env.exec(“猫の挨拶.txt”); console.log(結果.stdout); // “こんにちはn” console.log(result.exitCode); // 0 console.log(result.env); // 実行後の最終環境”>

import { Bash } from "just-bash";

const env = new Bash();
await env.exec('echo "Hello" > greeting.txt');
const result = await env.exec("cat greeting.txt");
console.log(result.stdout); // "Hellon"
console.log(result.exitCode); // 0
console.log(result.env); // Final environment after execution

const env = new Bash({
  files: { "/data/file.txt": "content" }, // Initial files
  env: { MY_VAR: "value" }, // Initial environment
  cwd: "/app", // Starting directory (default: /home/user)
  executionLimits: { maxCallDepth: 50 }, // See "Execution Protection"
});

// Per-exec overrides
await env.exec("echo $TEMP", { env: { TEMP: "value" }, cwd: "/tmp" });

JSON.stringify({ key: “value” }), “/data/remote.txt”: async () => (await fetch(“https://example.com”)).text(), “/data/static.txt”: “常にロードされます”, }, });”>

const env = new Bash({
  files: {
    "/data/config.json": () => JSON.stringify({ key: "value" }),
    "/data/remote.txt": async () => (await fetch("https://example.com")).text(),
    "/data/static.txt": "always loaded",
  },
});

{ const 名 = 引数[0] || “世界”; return { stdout: `こんにちは、${name}!n`、stderr: “”、exitCode: 0 }; }); const upper =defineCommand(“upper”, async (args, ctx) => { return { stdout: ctx.stdin.toUpperCase(), stderr: “”, exitCode: 0 }; }); const bash = new Bash({ カスタムコマンド: [hello, upper] }); await bash.exec(“こんにちは、アリス”); // “こんにちは、アリス!n” await bash.exec(“echo ‘test’ | upper”); // “テストn””>

import { Bash, defineCommand } from "just-bash";

const hello = defineCommand("hello", async (args, ctx) => {
  const name = args[0] || "world";
  return { stdout: `Hello, ${name}!n`, stderr: "", exitCode: 0 };
});

const upper = defineCommand("upper", async (args, ctx) => {
  return { stdout: ctx.stdin.toUpperCase(), stderr: "", exitCode: 0 };
});

const bash = new Bash({ customCommands: [hello, upper] });

await bash.exec("hello Alice"); // "Hello, Alice!n"
await bash.exec("echo 'test' | upper"); // "TESTn"

import { Bash } from "just-bash";
const env = new Bash(); // Uses InMemoryFs by default

パッケージ.json’); // メモリに残ります”>

import { Bash } from "just-bash";
import { OverlayFs } from "just-bash/fs/overlay-fs";

const overlay = new OverlayFs({ root: "/path/to/project" });
const env = new Bash({ fs: overlay, cwd: overlay.getMountPoint() });

await env.exec("cat package.json"); // reads from disk
await env.exec('echo "modified" > package.json'); // stays in memory

ファイル.txt’); // 実際のファイルシステムに書き込みます”>

import { Bash } from "just-bash";
import { ReadWriteFs } from "just-bash/fs/read-write-fs";

const rwfs = new ReadWriteFs({ root: "/path/to/sandbox" });
const env = new Bash({ fs: rwfs });

await env.exec('echo "hello" > file.txt'); // writes to real filesystem

メモ.txt’); // ワークスペースに書き込みます”>

import { Bash, MountableFs, InMemoryFs } from "just-bash";
import { OverlayFs } from "just-bash/fs/overlay-fs";
import { ReadWriteFs } from "just-bash/fs/read-write-fs";

const fs = new MountableFs({ base: new InMemoryFs() });

// Mount read-only knowledge base
fs.mount("/mnt/knowledge", new OverlayFs({ root: "/path/to/knowledge", readOnly: true }));

// Mount read-write workspace
fs.mount("/home/agent", new ReadWriteFs({ root: "/path/to/workspace" }));

const bash = new Bash({ fs, cwd: "/home/agent" });

await bash.exec("ls /mnt/knowledge"); // reads from knowledge base
await bash.exec("cp /mnt/knowledge/doc.txt ./"); // cross-mount copy
await bash.exec('echo "notes" > notes.txt'); // writes to workspace

import { MountableFs, InMemoryFs } from "just-bash";
import { OverlayFs } from "just-bash/fs/overlay-fs";
import { ReadWriteFs } from "just-bash/fs/read-write-fs";

const fs = new MountableFs({
  base: new InMemoryFs(),
  mounts: [
    { mountPoint: "/data", filesystem: new OverlayFs({ root: "/shared/data" }) },
    { mountPoint: "/workspace", filesystem: new ReadWriteFs({ root: "/tmp/work" }) },
  ],
});

import { createBashTool } from "bash-tool";
import { generateText } from "ai";

const bashTool = createBashTool({
  files: { "/data/users.json": '[{"name": "Alice"}, {"name": "Bob"}]' },
});

const result = await generateText({
  model: "anthropic/claude-sonnet-4",
  tools: { bash: bashTool },
  prompt: "Count the users in /data/users.json",
});

import { Sandbox } from "just-bash";

// Create a sandbox instance
const sandbox = await Sandbox.create({ cwd: "/app" });

// Write files to the virtual filesystem
await sandbox.writeFiles({
  "/app/script.sh": 'echo "Hello World"',
  "/app/data.json": '{"key": "value"}',
});

// Run commands and get results
const cmd = await sandbox.runCommand("bash /app/script.sh");
const output = await cmd.stdout(); // "Hello Worldn"
const exitCode = (await cmd.wait()).exitCode; // 0

// Read files back
const content = await sandbox.readFile("/app/data.json");

// Create directories
await sandbox.mkDir("/app/logs", { recursive: true });

// Clean up (no-op for Bash, but API-compatible)
await sandbox.stop();

# Execute inline script
just-bash -c 'ls -la && cat package.json | head -5'

# Execute with specific project root
just-bash -c 'grep -r "TODO" src/' --root /path/to/project

# Pipe script from stdin
echo 'find . -name "*.ts" | wc -l' | just-bash

# Execute a script file
just-bash ./scripts/deploy.sh

# Get JSON output for programmatic use
just-bash -c 'echo hello' --json
# Output: {"stdout":"hellon","stderr":"","exitCode":0}