Structured Logs

The structlog module develops the idea of vlogger by constructing a record using a chain of method calls.

Concept

When initialized, the logger starts a thread with a record handler. The logger has a number of methods, each of which creates a record with the corresponding logging level, e.g. info() .

By chaining method calls, the module user can create a record with any structure. The final .send() call sends the record to the handler for writing.

The record handler completely defines how to prepare the Record object for writing, how and whereto the writing will occur. The handler must implement the RecordHandler interface. Two ready-made handlers for recording are provided: TextHandler (the default) and JSONHandler for JSON formatted logs.

Usage

import structlog

fn main() {
    log := structlog.new()
    defer {
        log.close()
    }

    log.info().message('Hello, World!').send()
}

Output:

2026-01-03T09:33:35.366Z [INFO ] message: 'Hello, World!'

See also examples dir for more usage examples.