Replit Agent 3: The Autonomous Full-Stack Engineer

What is Replit Agent 3?

Launched in late 2025 and refined in 2026, Replit Agent 3 is a massive leap forward in AI-led development. While earlier versions acted as assistants, Agent 3 is a true collaborator capable of handling complex, hours-long trajectories with minimal human oversight. It is 10x more autonomous than Agent 2 and introduces a revolutionary "self-healing" loop where the AI actually tests the apps it builds in a live browser.

The platform has transitioned into a "Project Delegator" model. You provide a high-level goal, and Agent 3 manages the entire development cycle: planning the architecture, writing the code, provisioning the database, and verifying every button and API call before telling you the build is complete.

Key Features for 2026

• 200-Minute Max Autonomy: Agent 3 can work for over 3 hours continuously. This allows it to tackle massive tasks like building an end-to-end e-commerce platform or a complex B2B dashboard in a single session.

• Self-Healing Browser Testing: The Agent doesn't just guess if code works. It spins up a real browser, simulates user behavior (clicking, typing, logging in), and automatically fixes any bugs it encounters during the test.

• Agents Building Agents: A revolutionary "Stacks" feature where you use Agent 3 to create other specialized AI agents and automations—such as a Telegram bot for customer support or a Slack bot that queries your Notion database.

• Mobile App Preview & Deployment: Build and preview native mobile apps (iOS/Android) instantly via QR code using Expo. It handles the entire "Code-to-Device" flow autonomously.

• RulesSync Support: For developers, the 2026 update adds RulesSync for replit.md, allowing you to synchronize AI agent configurations across multiple projects effortlessly.

• Native Integration UI: When connecting to tools like Notion or Dropbox, the Agent surfaces a simple UI for secure authentication, eliminating the need to manually copy-paste API keys.

2026 Pricing: The "Pro" and "Core" Tiers

Replit recently overhauled its pricing (Jan 2026) to simplify credit management and collaboration.

• Replit Core Plan: $20 / month.

  • Best For: Solo developers and founders.

  • Features: Includes $25 in monthly credits and allows collaboration with up to 5 people for free.

• Replit Pro Plan: $100 / month.

  • Best For: Professional teams and startups.

  • Features: Includes higher credit discounts, 4x data retention (28 days), priority support, and pooled credits for up to 15 builders.

• Usage Credits: Both plans use an "effort-based" model where you can purchase credit packs to top up your account for major build pushes.

Replit Agent 3 vs. Replit Agent 2

Feature	Replit Agent 3	Replit Agent 2
Max Autonomy	200 Minutes	20 Minutes
Testing	Self-Healing (Browser)	Manual / Prompt-led
Automation	Builds Other Agents	Standard App Logic
Speed/Cost	3x Faster / 10x Cheaper	Baseline
Best For	Complex SaaS & Scaling	Simple MVPs & Layouts

Frequently Asked Questions

Can Agent 3 really test itself?

Yes. Using REPL-based verification, Agent 3 identifies "Potemkin interfaces" (features that look good but don't work) by clicking around the app like a real user. It captures logs, establishes cause-and-effect, and repairs the code if a button fails to trigger the correct database action.

Is it hard to switch from Agent 2 to Agent 3?

No. For existing projects, Replit provides "Autonomy Level" controls. You can choose "Low Autonomy" for a hands-on experience similar to Agent 2, or "Max Autonomy" to let Agent 3 take full control of a complex project for extended periods.

Can I monitor the Agent while I'm away?

Yes. Replit provides Live Monitoring on your phone. You can open the Replit app to see progress bars, logs of fixed bugs, and receive a notification the moment your app is ready to be shared.