Devin

Devin is not a coding assistant; it is a remote junior engineer that lives in the cloud. Unlike Copilot or Cursor, which predict your next keystroke, Devin takes a vague prompt—"migrate this database schema" or "fix the mobile responsiveness on the checkout page"—and disappears for 20 minutes to plan, code, test, and deploy the solution. It manages its own sandboxed environment with a browser, shell, and VS Code-like editor, allowing it to read documentation, debug its own errors, and run tests without your help.

Technically, Devin 2.0 (released mid-2025) is a significant leap from the viral demos of 2024. It now supports parallel agents, meaning you can spin up five instances to tackle different bugs simultaneously. The "interactive planning" phase is a standout feature: before writing a line of code, Devin presents a plan of attack for you to approve or tweak, drastically reducing the "hallucinated rabbit hole" problem of earlier agents.

However, the economics require a shift in mindset. You don't pay for a seat; you pay for work. The entry-level $20/month plan is effectively a trial, granting just 9 "Agent Compute Units" (ACUs)—roughly 2.25 hours of autonomous work. Real production value requires the $500/month Team plan or significant overage fees. If you treat it like a chatbot, you will burn money. If you treat it like a contractor you pay $11-$15/hour to handle grunt work (migrations, test coverage, dependency updates), the math starts to work.

Devin’s weakness is speed and transparency. It is not for real-time iteration. You assign a task and walk away. If it gets stuck, you often have to kill the session and pay for the wasted compute. For immediate "flow state" coding, Cursor is vastly superior. But for asynchronous maintenance and feature work that would otherwise consume your afternoon, Devin is the current state of the art. Use it if you have a backlog of "important but not urgent" tasks and the budget to outsource them to AI; skip it if you're a solo dev watching every dollar.

Pricing

The $20/month "Core" plan is deceptive. It includes only 9 Agent Compute Units (ACUs), where 1 ACU ≈ 15 minutes of active work. That's about 2 hours of engineering time per month. Once those run out, you pay $2.25 per additional ACU ($9/hour). The real utility starts at the $500/seat/month Team plan, which includes 250 ACUs (~60 hours of work). Compared to GitHub Copilot ($10/mo) or Cursor ($20/mo), Devin is priced as labor replacement, not software. Hidden cost: failed attempts and "stuck" agents still consume paid ACUs.

Technical Verdict

The API is REST-based and allows you to programmatically spin up sessions, making it possible to build "agentic CI/CD" pipelines. The Python SDK is a thin wrapper around this. Latency is high—expect minutes, not milliseconds. Reliability is improved in v2.0 but still prone to loops in complex codebases. Documentation is clean but sparse on the deep internals of the proprietary agent loop.

Quick Start

# pip install requests
import requests
 
headers = {"Authorization": "Bearer YOUR_API_KEY"}
data = {"prompt": "Create a Python script that calculates Fibonacci numbers"}
 
# Start a session programmatically
resp = requests.post("https://api.devin.ai/v1/sessions", json=data, headers=headers)
print(f"Session started: {resp.json()['session_id']}")

Watch Out

• The $20 plan is effectively a demo; meaningful work requires the $500 tier or heavy overages.
• Latency is significant; simple fixes can take 10+ minutes of 'thinking' time.
• Agents can get stuck in npm install or debugging loops, burning expensive credits.
• No self-hosting option means your code leaves your perimeter (unless on Enterprise).