substrate logs to read the persistent log file written by the long-lived substrate mcp and substrate serve processes. The file is gitignored and local-only. Reading crosses a rotation boundary correctly, so -n is honoured even when the log just rotated.
Usage
Options
number
How many lines to print. Defaults to
50.flag
Filter to errors only.
Who Writes to the Log
Only the long-lived processes write here —substrate mcp and substrate serve. Short-lived commands do not log, so substrate logs after a failed one-shot command will not explain it.
An agent’s handled tool errors land here, which makes substrate logs --errors the way an agent reviews its own error trail. Routine gate blocks and stale-version retries are excluded on purpose — they are normal operation, not faults.