Stream Command

What You’ll Learn

Streaming command output with sbx.commands.run_stream() (Python) / sbx.commands.runStream() (TypeScript)
Real-time on_stdout / on_stderr callbacks that fire as each line arrives
Inspecting the final accumulated CommandResult after the stream completes
Proper cleanup with try/finally and sbx.kill()

Prerequisites

Code Walkthrough

Python
TypeScript

Use run_stream() with on_stdout and on_stderr keyword callbacks. The call blocks until the command exits and returns a CommandResult with the full accumulated output:

cmd = 'for i in 1 2 3 4 5; do echo "Processing step $i..."; sleep 0.5; done'

result = sbx.commands.run_stream(
    cmd,
    on_stdout=lambda line: print(f"[STDOUT] {line}"),
    on_stderr=lambda line: print(f"[STDERR] {line}"),
)

print(f"stdout:\n{result.stdout}")
print(f"stderr: {result.stderr!r}")
print(f"exit_code: {result.exit_code}")

Each line is delivered to on_stdout as it is emitted — no buffering until the command finishes. The returned result.stdout contains all lines joined together.

Use runStream() with onStdout and onStderr in the options object:

const cmd =
  'for i in 1 2 3 4 5; do echo "Processing step $i..."; sleep 0.5; done';

const result = await sbx.commands.runStream(cmd, {
  onStdout: (line: string) => console.log(`[STDOUT] ${line}`),
  onStderr: (line: string) => console.log(`[STDERR] ${line}`),
});

console.log(`stdout:\n${result.stdout}`);
console.log(`stderr: ${JSON.stringify(result.stderr)}`);
console.log(`exit_code: ${result.exitCode}`);

The await resolves once the command exits. result.stdout holds the complete accumulated output.

Expected Output

==================================================
Declaw Stream Command Example
==================================================

--- Creating Sandbox ---
Sandbox created: sbx_abc123

--- Streaming Command Output ---
[STDOUT] Processing step 1...
[STDOUT] Processing step 2...
[STDOUT] Processing step 3...
[STDOUT] Processing step 4...
[STDOUT] Processing step 5...

--- Final Result ---
stdout:
Processing step 1...
Processing step 2...
Processing step 3...
Processing step 4...
Processing step 5...
stderr: ''
exit_code: 0

--- Cleaning Up ---
Sandbox killed.

==================================================
Done!
==================================================

Run Command Background Process

Getting Started

Built-in Templates

Commands

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Agent-in-Sandbox

Real-World Patterns

Security Demos

Stream Command

What You’ll Learn

Prerequisites

Code Walkthrough

Expected Output

​What You’ll Learn

​Prerequisites

​Code Walkthrough

​Expected Output

What You’ll Learn

Prerequisites

Code Walkthrough

Expected Output