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HTML Logger

The HTML logger creates interactive, self-contained HTML files that make it easy to navigate complex multi-agent conversations in Langroid.

Enabling the HTML Logger

The HTML logger is enabled by default in TaskConfig:

import langroid as lr

# HTML logging is automatically enabled
task = lr.Task(agent)

# To disable HTML logging
task = lr.Task(agent, config=lr.TaskConfig(enable_html_logging=False))

# To change the log directory (default is "logs/")
task = lr.Task(agent, config=lr.TaskConfig(logs_dir="my_logs"))

Log Files

Langroid creates three types of log files in the logs/ directory:

  1. HTML Log: <name>.html - Interactive, collapsible view
  2. Plain Text Log: <name>.log - Traditional text log with colors
  3. TSV Log: <name>.tsv - Tab-separated values for data analysis

The <name> is determined by:

  • The task name (if specified)
  • Otherwise, the agent name
  • Falls back to "root" if neither is specified

When a task starts, you'll see a clickable file:// link in the console: 

WARNING - 📊 HTML Log: file:///path/to/logs/task-name.html

Key Features

Collapsible Entries

Each log entry can be expanded/collapsed to show different levels of detail:

  • Collapsed: Shows only the entity type (USER, LLM, AGENT) and preview
  • Expanded: Shows full message content, tools, and sub-sections

Visual Hierarchy

  • Important responses are shown at full opacity
  • Intermediate steps are faded (0.4 opacity)
  • Color-coded entities: USER (blue), LLM (green), AGENT (orange), SYSTEM (gray)

Tool Visibility

Tools are clearly displayed with:

  • Tool name and parameters
  • Collapsible sections showing raw tool calls
  • Visual indicators for tool results

Auto-Refresh

The HTML page automatically refreshes every 2 seconds to show new log entries as they're written.

Persistent UI State

Your view preferences are preserved across refreshes:

  • Expanded/collapsed entries remain in their state
  • Filter settings are remembered

Example

Here's what the HTML logger looks like for a planner workflow:

HTML Logger Screenshot

In this example from examples/basic/planner-workflow-simple.py, you can see:

  • The planner agent orchestrating multiple tool calls
  • Clear visibility of IncrementTool and DoublingTool usage
  • The filtered view showing only important responses
  • Collapsible tool sections with parameters

Benefits

  1. Easy Navigation: Quickly expand/collapse entries to focus on what matters
  2. Tool Clarity: See exactly which tools were called with what parameters
  3. Real-time Updates: Watch logs update automatically as your task runs
  4. Filtered Views: Use "Show only important responses" to hide intermediate steps