Config: Log · rousseau-agent docs

Overview

Rousseau uses Go's standard library log/slog for all structured logging. The log.* block picks the level and format; concrete handler construction lives in internal/cli/root.go:newLogger.

Logs go to stderr by default. rousseau mcp requires this because stdout is reserved for the JSON-RPC transport.

`log.*`

Field	Type	Default	Required	Description	Source
`log.level`	string	`info`	no	One of `debug`, `info`, `warn`, `warning`, `error`. Case-insensitive. Unknown values fall back to `info`.	`LogConfig.Level` in `internal/config/config.go`; parsed by `newLogger`
`log.format`	string	`text`	no	`text` = `slog.TextHandler`, `json` = `slog.JSONHandler`. Anything else defaults to text.	`LogConfig.Format`

Level semantics

Every request/response, every tool-call, every whatsmeow protocol frame. Use in development only — extremely verbose.

Non-recoverable per-request failures. Structured errors with attributes like err, event, session_id, sender.

Log formats

text — human-friendly key=value pairs. Good for journalctl -f on a workstation.
json — one JSON object per line. Ship to Loki, Datadog, ELK, or any log aggregator with a JSON parser. Recommended in production.

Standard log-event names

Rousseau uses dot-separated event names as the msg field:

Prefix	Emitted by
`whatsapp.*`	`internal/transport/whatsapp/`
`signal.*`	`internal/transport/signal/`
`telegram.*`	`internal/transport/telegram/`
`matrix.*`	`internal/transport/matrix/`
`slack.*`	`internal/transport/slack/`
`discord.*`	`internal/transport/discord/`
`email.*`	`internal/transport/email/`
`sms.*`	`internal/transport/sms/`
`imessage.*`	`internal/transport/imessage/`
`router.transport.*`	`internal/transport/router.go`
`agent.*`	`internal/agent/`
`cron.*`	`internal/cron/`
`mcp.*`	`internal/mcp/`

See Reference: Logs for the full event catalogue.

Whatsmeow log-level mapping

The whatsmeow library needs its own log level; rousseau translates from log.level via whatsappLogLevel in internal/cli/whatsapp.go:

`log.level`	Whatsmeow level
`debug`	`DEBUG`
`info` (default)	`INFO`
`warn`, `warning`	`WARN`
`error`	`ERROR`

Environment variables

Variable	Effect
`ROUSSEAU_LOG_LEVEL`	Overrides `log.level`.
`ROUSSEAU_LOG_FORMAT`	Overrides `log.format`.

Worked examples

# Development
log:
  level: debug
  format: text

# Production (containerised)
log:
  level: info
  format: json

# One-off debug run without touching the config file
ROUSSEAU_LOG_LEVEL=debug ROUSSEAU_LOG_FORMAT=text rousseau whatsapp 2>debug.log

Reference: Logs — the event catalogue.
Best Practices: Cost control — logs feed cost dashboards.
Deployment — journalctl + Quadlet.
Reference: Config: State