If you've ever piped a dev server's output into jq to make the JSON logs

readable, you know this dance:

npm run dev | jq

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{ "level" : 30 , "msg" : "server started" , ... } jq: error (at <stdin>: 0 ): Cannot index string with "level"

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It worked for exactly three lines — until your app printed a startup banner, or a

plain console.log , or a stack trace. jq hit one line that wasn't valid JSON

and aborted the entire stream . Now you're back to reading raw JSON with your

eyeballs.

The thing is, real log output is never pure JSON. It's a mix: structured lines

from your logger (pino, winston, structlog, zap…), plus framework noise, plus

whatever you print() -debugged at 2am.…