Running on Bun

Run a cli app#

toCliHandler(app) from @rhythmjs/cli/run takes the Rhythm host app and returns (argv: string[]) => Promise<number>. It parses flags, seeds the cli context, runs the pipeline once, flushes response.stdout then response.stderr to the console, and resolves with the exit code. Nothing calls process.exit() for you; set process.exitCode and close what you opened.

#!/usr/bin/env bun
import { toCliHandler } from "@rhythmjs/cli/run";
import { app } from "./app";

process.exitCode = await toCliHandler(app)(process.argv.slice(2));

Pipe stdin#

When input is piped or redirected, ctx.stdin is a ReadableStream<Uint8Array> from Bun.stdin.stream(), Bun's native stdin with no Node stream conversion. On a TTY it is null, so handlers can branch on interactivity.

cli.command("import", async (ctx) => {
  if (ctx.stdin === null) {
    ctx.response.exit(1).printError("pipe a file: cat data.json | myapp import");
    return;
  }
  const body = await new Response(ctx.stdin).json();
  ctx.response.print(`imported ${Object.keys(body).length} records`);
});

Prompt I/O#

createPrompt() wires the prompt surface to Bun directly: questions write to process.stdout, and answers are read from Bun's async-iterable console (one await per line, no readline interface). close() releases the line iterator; call it when the command finishes. See interactive prompts for the startup-context pattern.

Compatibility aliases#

The package is coupled to Bun on purpose; there are no Node or Deno builds. Two subpaths from the earlier multi-runtime layout remain as aliases so old imports keep resolving: @rhythmjs/cli/adapters/bun → ./run and @rhythmjs/cli/adapters/context → ./context. New code should import ./run and ./context.