Module log 

Structured logging to Workers Logs: levels, request-scoped fields, JSON lines (Rails’ Rails.logger and tagged logging).

Every Ctx carries a Logger: in a request it is tagged with the request’s request_id, method and path, so each line of a request can be found together in the Workers Logs dashboard. Add fields with Logger::with (Rails’ logger.tagged):

use axum::extract::{Path, State};
use ocre::{Ctx, Result};

async fn pay(State(ctx): State<Ctx>, Path(order_id): Path<i64>) -> Result<&'static str> {
    let log = ctx.log().with("order_id", order_id);
    log.info("payment started");
    log.debug(format_args!("cart: {:?}", vec![1, 2])); // formatted only when debug is on
    Ok("OK")
}

Levels and formats

Two Worker variables configure logging; they are read on every request, job batch and cron run (no binding call):

Variable	Values	Default in ocre dev (debug build)	Default after ocre deploy (release build)
LOG_LEVEL	debug, info, warn, error, off (warning, fatal accepted)	debug	info
LOG_FORMAT	json, text	text	json

json writes each line as a JavaScript object ({"level": "info", "message": "...", "request_id": "...", ...}): Workers Logs indexes every field, so the dashboard can filter on $metadata.request_id or your own fields. text writes INFO payment started order_id=42 request_id=..., easier to read in the ocre dev terminal. Lines go to console.debug, console.info, console.warn or console.error, so the level also shows in the dashboard and in ocre logs.

Field names matching FILTERED_PARAMETERS (password, email, token…) are written as [FILTERED], at any depth.

Free plan

Workers Logs keeps 200,000 events a day for 3 days on the free plan (September 2026); each request is one event plus one per line logged. Above that, events are sampled, never billed. info in production logs only what the app asks for; Ocre’s own per-request and SQL lines are debug, so they cost nothing after ocre deploy. Messages passed as format_args!(...) are only formatted when their level is on.

Structs

Logger

Writes log lines with a set of fields; cheap to clone (see the module documentation).

Enums

Format

How log lines are written: see the module documentation.

Level

Severity of a log line (Rails’ :debug, :info, :warn, :error).

Constants

LOG_FORMAT

Worker variable choosing the line format: json or text.

LOG_LEVEL

Worker variable setting the lowest level logged: debug, info, warn, error or off.