feat: Free: Add agentwatch compare command to A/B test two models side-by-side

[SHAURYASANYAL3]

Resolves #423

Overview

This Pull Request implements the highly requested Free: Add agentwatch compare command to A/B test two models side-by-side functionality into the AgentWatch CLI.

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Why do we need this?

For a 5-year-old: If we have a red robot and a blue robot, we want a command that watches them race and tells us who was faster and who used less energy!

For developers: Choosing between models (e.g., gpt-3.5 vs claude-3-haiku) involves trade-offs between cost, latency, and success rate. An easy A/B testing tool helps make data-driven decisions.

What is it?

A new CLI command agentwatch compare --task "..." --model-a gpt-3.5 --model-b claude-3 that runs a prompt on two models concurrently. This is a FREE feature.

Suggestions for Implementation

• Use asyncio.gather to launch both agents concurrently to save time.
• Capture latency, total tokens, and output length.
• Print a rich comparison table highlighting the winner in each category.

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Implementation Notes 🛠️

• Implemented via the typer framework in agentwatch/cli/main.py.
• Includes a beautiful terminal UI response using rich.
• Validated to pass all rigorous test suites, including conditional dependency checks.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 52aed59b-562d-471f-b519-13065bb72551

📥 Commits

Reviewing files that changed from the base of the PR and between 19bbbeb and 21944d6.

📒 Files selected for processing (2)

• agentwatch/cli/main.py
• tests/test_protocol.py

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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🧪 PR Test Results

Check	Result
Tests (pytest tests/)	✅ success
Lint (ruff check .)	❌ failure
Coverage (agentwatch)	74.06%

_{Python 3.12 · commit 21944d6}