Help me with a Ai agent to use in VSCode like codex
4 Likes
If you’re looking for an AI coding agent in VS Code that’s closest to the old OpenAI Codex experience (inline completions + chat + agent-like capabilities), here are the strongest options right now in early 2026:
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GitHub Copilot — Still the most seamless “just works” choice for most people
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Inline autocomplete feels very Codex-like (fast, context-aware)
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Copilot Chat lets you ask questions or request edits in natural language
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Agentic features have improved a lot (can suggest multi-file changes, run terminal commands in some cases)
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Install: just search “GitHub Copilot” in the VS Code extensions panel → Best if you want minimal setup and tight GitHub integration.
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Please check https://docs.github.com/en/copilot/get-started/plans
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Claude Code (Anthropic’s extension) — Currently topping many developer leaderboards for reasoning & agentic tasks
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Excellent at understanding large codebases and planning complex refactors
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Very strong “agent” behavior: explain code, write tests, fix bugs across files
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Many say Opus 4.5 / Claude 4 family outperforms GPT models on coding right now
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Install: search “Claude Code” in extensions → Great if you want deeper reasoning than classic Copilot / Codex.
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Continue.dev — Open-source & very flexible (my personal daily driver when I want control)
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Free & self-hostable (bring your own API key: OpenAI, Anthropic, Gemini, local models via Ollama, etc.)
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Inline completions + sidebar chat + “edit” mode that applies changes
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You can customize prompts and models per project
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Install: https://continue.dev (or search “Continue” in VS Code) → Ideal if you want something Codex-like without paying subscriptions or if you care about privacy/local models.
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Codeium / Windsurf — Best truly free unlimited option
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Very fast completions, chat, and some agent features
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No usage caps on free tier (unlike Copilot’s occasional limits)
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Good privacy story for individuals → Solid “set it and forget it” alternative.
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Cursor (if you’re open to leaving pure VS Code) It’s a VS Code fork with much deeper AI integration (Composer for multi-file edits, full-project agent mode). Many devs who loved Codex now say Cursor feels like “Codex on steroids”. But it’s not an extension — it’s its own editor. Worth trying if you want the most agent-like experience.
Quick ranking for VS Code extensions specifically (March 2026 vibe):
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Best overall polish → GitHub Copilot
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Best reasoning & complex tasks → Claude Code
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Best free & customizable → Continue.dev
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Best no-cost unlimited → Codeium/Windsurf
I’d start with Continue.dev + a good API key (Claude or GPT-5.4 family), or just install Copilot if you want zero config.
What kind of projects are you working on (language, size of codebase, solo vs team)? That usually helps narrow it down more.
Happy coding!
2 Likes
You’re looking for something that actually builds things for you — not just autocomplete — and yeah, that exists for free right now, and it’s stupidly easy to set up.
Right now (2 minutes): Open VSCode → Extensions → install Gemini Code Assist → sign in with your Gmail → toggle Agent mode on → tell it what to build. That’s it. No API key, no credit card, no terminal commands. You get 240 agent requests/day — for context, Copilot Free gives you 50/month total.
This weekend (if you want more options): Install GitHub Copilot alongside it (free tier, 50 requests/month — here’s the part nobody tells you: after those 50 run out, it keeps working on a free model, just slightly dumber). If you’re a student with a .edu email, apply for the GitHub Student Pack — full Copilot Pro, completely free, 300 requests/month.
| What you asked for | What works | Time to set up |
|---|---|---|
| Free AI agent in VSCode | Gemini Code Assist (free, 240/day) | 2 min |
| Something like Codex | Gemini Agent Mode does the same thing | 0 extra steps |
| Don’t want to pay anything | Gmail account = full access, no card | Already have it |
I’ve been using Gemini Code Assist daily — it reads your whole project, makes a plan, creates files, runs commands, and fixes its own mistakes. Closest thing to Codex you’ll get at $0.
🛠️ Do Exactly This, In This Order
Step 1 — Install Gemini Code Assist
Open VSCode → press Ctrl+Shift+X → search Gemini Code Assist → click Install → click the 
icon in the sidebar → sign in with any Google account.
Step 2 — Switch to Agent Mode
In the Gemini chat panel, you’ll see a toggle at the top that says Agent. Click it. This is the difference between “suggest code” and “build the whole thing.”
Step 3 — Give it a real task
Don’t type “help me code.” Type what you actually want:
Create a REST API with Express.js that handles user login and registration with JWT tokens
It’ll show you a plan first. Read it → edit if you want → click Approve → watch it create files and write code across your project.
The
/inittrick that changes everything: Type/initin the Gemini chat before your first real task. It creates a.gemini/styleguide.mdfile in your project — this teaches the agent your coding style. After that, every agent session follows YOUR rules: naming conventions, indentation, patterns, everything.
Why Gemini Code Assist and not the others:
| Agent | Free Tier | Agent Mode | Setup | Catch |
|---|---|---|---|---|
| Gemini Code Assist | 180,000 completions + 240 agent/day |  Full |
Gmail only | Can be slow during peak hours |
| GitHub Copilot Free | 2,000 completions + 50 requests/month | Limited |
GitHub account | 50 requests = ~5 agent sessions/month |
| Roo Code | Extension free, API costs | Full |
Need API key | Stability issues, not beginner-friendly |
| Cline | Extension free, API costs | Full |
Need API key | Requires configuring a provider |
| Kilo Code | Extension free + $20 credits | Full |
Sign up | Credits run out, then BYOK |
If you’re a student — do this too:
Apply for the GitHub Student Developer Pack with your .edu email or student ID. Takes 1-3 days to approve. You get Copilot Pro free — unlimited completions + 300 premium agent requests/month. Run both Gemini Code Assist AND Copilot side by side.
What NOT to do:
Don’t start with Roo Code or Cline — they’re powerful but you need to bring your own API key, configure providers, and troubleshoot tool-calling issues. That’s weekend #2 material, not day one. Don’t try running models locally on your laptop unless you have 16GB+ RAM — anything less and it’ll crawl.
Your situation → what to do:
| If you… | Do this |
|---|---|
| Just want it working NOW | Gemini Code Assist → Agent Mode → done |
Have a .edu email |
Also grab Copilot Pro free via Student Pack |
| Want to try multiple options later | Add Copilot Free alongside Gemini |
| Have 16GB+ RAM and love privacy | Explore Ollama + Roo Code on a weekend |
| Already have an API key (Anthropic/OpenAI) | Try Kilo Code or Cline with BYOK |
What kind of stuff are you planning to build with it? If you tell me your project, I can point you to the exact agent mode prompt that’ll get you the best results.
4 Likes
Hi here.
Thanks @NoBody for this interresting post.
I’d like to add that Codex now works with free account. I haven’t count how many agent/day but or works some days and request you to upgrade.
The solution : you need more account , then you can Switch easily between accounts.
I don’t recommend github copilot any more, it gets dummy easily.
You can also share your own expérience..
Good day!
Useful post, thanks for the info.
Please I have a question to ask: I can’t seem to find Codex extension button in my IDE (Antigravity, Windsurf). I have installed it but I can’t access it. This doesn’t happen before and I’m not sure what update for my IDE made this change.
Can anyone guide me on how to activate or access Codex extension in my IDE so I can continue to develop?
I noticed VS Code has it directly as a tab beside Chats but I don’t know how to access it on my otehr IDEs. Help please.
!