kaappi-log

Structured logging library for Kaappi Scheme.

Pure Scheme — no C dependencies, no build step.

Install

thottam install kaappi-log

Quick start

(import (kaappi log))

(log-info "server started" '("port" . 8080))
;=> 1719100000 [INFO] server started port=8080

(log-error "failed" '("code" . 500) '("path" . "/api"))
;=> 1719100000 [ERROR] failed code=500 path=/api

API

Log functions

(log-debug msg field ...)    ; DEBUG level
(log-info msg field ...)     ; INFO level
(log-warn msg field ...)     ; WARN level
(log-error msg field ...)    ; ERROR level
(log-fatal msg field ...)    ; FATAL level

Fields are pairs: '("key" . value). Values can be strings, numbers, or booleans.

Configuration

(log-set-level! LOG-WARN)          ; suppress DEBUG and INFO
(log-set-port! (current-output-port))  ; log to stdout
(log-set-format! 'json)           ; JSON output
(log-set-format! 'text)           ; text output (default)

Context fields

(log-with-fields '(("req_id" . "abc123"))
  (lambda ()
    (log-info "processing")    ; includes req_id=abc123
    (log-info "done")))        ; includes req_id=abc123

Output formats

Text (default)

1719100000 [INFO] request method=GET path=/api status=200

JSON

{"time":"1719100000","level":"INFO","msg":"request","method":"GET","path":"/api","status":200}

Log levels

Level	Constant	Value
DEBUG	LOG-DEBUG	0
INFO	LOG-INFO	1
WARN	LOG-WARN	2
ERROR	LOG-ERROR	3
FATAL	LOG-FATAL	4

License

MIT