## TL;DR
AI coding assistants evolved from autocomplete to autonomous agents. By 2026, Cursor leads IDE-based workflows, Claude Code dominates terminal agentic coding (77.2% SWE-bench), and GitHub Copilot remains the enterprise standard with 55% productivity gains.

## Core Explanation
Three generations: (1) autocomplete — Copilot suggests next line; (2) chat — ask questions, generate functions; (3) agents — write, test, debug, deploy autonomously. SWE-bench measures end-to-end bug-fixing ability on real GitHub issues.

## Detailed Analysis
Cursor (2024) combined IDE with AI chat and inline editing. Devin (Cognition AI, 2024) demonstrated full-stack development automation. Claude Code (2025) achieved breakthrough 77.2% SWE-bench score via test-driven development loops. The trend is toward increasingly autonomous coding workflows.

## Further Reading
- SWE-bench Leaderboard
- Cursor Documentation
- GitHub Copilot Research