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Documentation Index

Fetch the complete documentation index at: https://docs.coreweave.com/llms.txt

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Stream logs from a sandbox’s main process with stream_logs(). This captures stdout/stderr from the command passed to Sandbox.run(). Output from exec() commands is not included (see the execution guide for Process.stdout/Process.stderr). Returns a StreamReader that yields log lines. Iterate synchronously or asynchronously.
Sandboxes created with the default command (tail -f /dev/null) produce no log output. To use stream_logs(), pass a command that writes to stdout/stderr when calling Sandbox.run().

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Retrieve recent logs

for line in sandbox.stream_logs(tail_lines=100):
    print(line, end="")

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Follow mode

Stream logs continuously, like tail -f. The iterator blocks until new data arrives. 
for line in sandbox.stream_logs(follow=True):
    print(line, end="")
Press Ctrl-C to stop when iterating in follow mode.

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Filter by time

Only retrieve logs after a specific timestamp. 
from datetime import datetime, timezone

since = datetime(2026, 2, 20, 14, 0, 0, tzinfo=timezone.utc)
for line in sandbox.stream_logs(since_time=since):
    print(line, end="")

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Timestamps

Prefix each line with an ISO 8601 timestamp from the server. 
for line in sandbox.stream_logs(tail_lines=10, timestamps=True):
    print(line, end="")
# Output: 2026-02-20T14:30:00Z some log line

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Async iteration

async for line in sandbox.stream_logs(follow=True):
    print(line, end="")

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Retrieving logs from stopped sandboxes

You can retrieve historical logs from sandboxes that have already completed, failed, or been terminated: 
sb = Sandbox.from_id("sbx-abc123").result()
for line in sb.stream_logs(tail_lines=50):
    print(line, end="")
Only follow=False (the default) is supported for stopped sandboxes.

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What are container logs?

Container logs capture stdout and stderr from the sandbox’s main process (PID 1). Commands run with exec() produce output on their own streams (Process.stdout/Process.stderr), not container logs. To generate logs visible to stream_logs(), your sandbox command must write to stdout or stderr.
Looking for exec output? See the command execution guide for streaming stdout/stderr from commands run with exec().

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See also

Last modified on April 21, 2026