02-logging-and-levels

02-logging-and-levels

What you’ll learn

• Emitting structured logs from a tool
• Changing verbosity via logging/setLevel
• Structured output when jq/gojq is available; minimal mode disables this example

Prereqs

• Bash 3.2+
• jq or gojq required; without it the server enters minimal mode and this example is unavailable

Run

./examples/run 02-logging-and-levels

Transcript

> logging/setLevel {"level":"debug"}
> tools/call example-logger
< notifications/message ... "example-logger" ...
< {"result":{"content":[{"type":"text","text":"Check your logging notifications"}]}}

Success criteria

• tools/list shows example-logger
• Setting level to debug yields notifications/message entries from the tool

Troubleshooting

• Ensure scripts are executable (chmod +x examples/run examples/02-logging-and-levels/tools/*/tool.sh).
• If no logs appear, confirm logging/setLevel to debug or info.
• If you see minimal-mode warnings, install jq/gojq; minimal mode disables tools/resources/prompts.
• Avoid CRLF in requests; send LF-only NDJSON.
• To see full paths in debug logs or manual-registration output in warnings/errors, set MCPBASH_LOG_VERBOSE=true (security risk: exposes file paths and usernames).