How to Use an AI Coding Agent for Free

Cline is an open-source AI coding agent that runs inside VS Code. You can use it without paying in two ways: pick a model tagged FREE during one of Cline's promotions, or connect a free OpenRouter API key and choose a model whose ID ends in :free. Both have usage caps, so treat them as a way to try agent workflows rather than a full-time setup.

What you get

• Cline free models: select models are free in the Cline IDE extension and CLI during rotating, limited-time promotions, up to a usage quota. Cline does not publish a fixed list or the quota size. See Cline free models.
• OpenRouter free models: model variants ending in :free cost nothing to call. Limits are 20 requests per minute and 50 requests per day, rising to 1,000 requests per day once you have bought at least 10 credits in total. See OpenRouter free models.
• Neither option requires a card to start.

Steps

Install Cline

1. In VS Code, open the Extensions view (Ctrl/Cmd + Shift + X), search for "Cline" and click Install.
2. Open Cline from the sidebar, then click the settings icon in the Cline panel.

Option A: Cline free models

3. Set API Provider to Cline and click Sign In to create or log in to your Cline account (Google, GitHub or email).
4. Open the Model dropdown and pick a model tagged FREE. If none is tagged, no promotion is running right now; use option B.

Option B: OpenRouter free models

3. Sign in at openrouter.ai and create an API key on the keys page in your account settings.
4. In Cline settings, set API Provider to OpenRouter and paste the key into the OpenRouter API Key field.
5. In the Model dropdown, choose a model whose ID ends in :free, or openrouter/free, OpenRouter's router that picks a free model for each request. The current free list is at openrouter.ai/models?variant=free.

Start a task

6. Open a project folder and describe a small, contained task. Review each file edit and command Cline proposes before approving it.

Limits and the catch

• Agents use requests fast. A single Cline task can make many model calls, so OpenRouter's 50 requests per day can run out after one or two tasks. Buying 10 credits once raises the cap to 1,000 per day.
• Daily caps reset per UTC day. Extra OpenRouter accounts or keys do not raise your limits.
• Free lineups rotate. Both Cline promotions and OpenRouter :free models change over time, and a model you used last month may be gone.
• Data use. Cline says free model usage may be used to help improve model performance and quality. Don't send code you can't share.
• Cline free models work only in the IDE extension and CLI, not through the Cline API. When a promotion's quota ends, the options are ClinePass ($9.99 per month), pay-as-you-go Cline credits, or your own API key.

If it doesn't work

• 429 errors from OpenRouter: you hit 20 requests per minute or your daily cap. Wait, or buy 10 credits to lift the daily cap.
• 402 errors on a free model: your OpenRouter balance is negative. Add credits to bring it above zero.
• Routing or privacy errors: OpenRouter only routes to providers that match the privacy settings on your account. If a free model won't route, check whether those settings exclude its providers.
• No FREE tag in Cline: no promotion is active for your account; switch to OpenRouter.
• The model can't handle tool use: small free models sometimes fail Cline's file-edit format. Try a larger free model or a coding-focused one.