Changelog

New updates and improvements at Cloudflare.

exec() is now available for Containers

Jun 18, 2026

exec() is now available for Containers. Use this.ctx.container.exec() to start processes inside a running Container, stream standard input and output, inspect exit codes, and signal each process.

Call exec() from a class extending Container, or from another Durable Object through this.ctx.container. The associated Container must already be running.

This example starts the Container when needed, then reads its Node.js version:

JavaScript
TypeScript

import { Container } from "@cloudflare/containers";

export class MyContainer extends Container {
  async readVersion() {
    if (!this.ctx.container.running) {
      await this.start();
    }

    const process = await this.ctx.container.exec(["node", "--version"]);
    const output = await process.output();
    const decoder = new TextDecoder();

    return {
      exitCode: output.exitCode,
      stdout: decoder.decode(output.stdout),
      stderr: decoder.decode(output.stderr),
    };
  }
}

import { Container } from "@cloudflare/containers";

export class MyContainer extends Container {
  async readVersion() {
    if (!this.ctx.container.running) {
      await this.start();
    }

    const process = await this.ctx.container.exec(["node", "--version"]);
    const output = await process.output();
    const decoder = new TextDecoder();

    return {
      exitCode: output.exitCode,
      stdout: decoder.decode(output.stdout),
      stderr: decoder.decode(output.stderr),
    };
  }
}

The command array starts an executable directly, without an implicit shell. Invoke a shell explicitly for pipes, redirects, or variable expansion.

One RPC method can coordinate multiple exec() calls in one caller-to-Durable Object round trip. It can also pass byte-oriented ReadableStream input or return streamed output with flow control.

For options and streaming examples, refer to Execute commands.