Logging

Logger class, LogLevel, AgentConfig logLevel, and formatted agent run output in RadarOS.

Logging

RadarOS includes a built-in Logger with colored terminal output and structured agent run formatting. Control verbosity via logLevel in AgentConfig.

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Logger Class

The Logger is used internally by agents. You can also instantiate it directly:

import { Logger } from "@radaros/core";

const logger = new Logger({
  level: "info",
  color: true,
  prefix: "myapp",
});

logger.info("Agent started");
logger.debug("Tool call", { toolName: "getWeather", args: { city: "Tokyo" } });

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LogLevel

Level	Order	Use Case
debug	0	Tool call details, arguments, results
info	1	Agent start/end, token usage, duration
warn	2	Warnings
error	3	Errors
silent	4	No logging (default for agents)

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Setting logLevel in AgentConfig

Control agent logging with the logLevel property:

const agent = new Agent({
  name: "ToolBot",
  model: openai("gpt-4o"),
  tools: [weatherTool],
  logLevel: "debug",  // "debug" | "info" | "warn" | "error" | "silent"
});

• "debug" — Logs tool calls, arguments, and results (verbose).
• "info" — Logs agent start, output, token usage, and duration.
• "silent" — No logs (default).

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What Gets Logged

Agent start

When a run begins: agent name and input preview.

Tool calls

At debug level: tool name and arguments.

Tool results

At debug level: tool name and result preview (truncated).

Token usage

At info level: prompt tokens, completion tokens, total tokens.

Duration

At info level: wall-clock duration (ms or seconds).

Agent end

When a run completes: output preview and summary.

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LoggerConfig

Property	Type	Default	Description
level	LogLevel	"info"	Minimum level to log.
color	boolean	process.stdout.isTTY !== false	Enable colored output. Auto-disabled when not a TTY.
prefix	string	"radaros"	Prefix shown in log lines. Agents use their name as prefix.

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Colored Terminal Output

The logger uses ANSI escape codes for colored output:

• Cyan — Agent name, box borders
• Magenta — Tool names
• Green — Token counts, success indicators
• Yellow — Duration, string values
• Gray — Timestamps, metadata
• Red — Errors

Box-drawing characters (┌, │, └, ─) create a structured layout for agent runs.

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Example Output

With logLevel: "info":

┌─ Agent: ToolBot ───────────────────────────────────────────────────────
│ Input:   What's the weather in Tokyo? Also, what's 42 * 17?
│
│ Output:  Tokyo is 22°C and sunny. 42 * 17 = 714.
│
│ Tokens: ↑ 245  ↓ 38  Σ 283
│ Duration: 1.2s
└────────────────────────────────────────────────────────────────────────

With logLevel: "debug", additional lines appear for each tool call:

│ ⚡ getWeather
│   { "city": "Tokyo" }
│ ✓ getWeather →
│   Tokyo: 22°C, sunny
│
│ ⚡ calculator
│   { "expression": "42 * 17" }
│ ✓ calculator →
│   714

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Example: Enabling Logging

Info level (summaries)

const agent = new Agent({
  name: "assistant",
  model: openai("gpt-4o"),
  logLevel: "info",
});