How to Add Free API Keys to OpenCode and Use Its Free Models

In short: OpenCode is a free, open-source AI coding app for Windows, Mac and Linux. It comes with some free models of its own, and you can add a free API key from Gemini, Groq, OpenRouter or Cloudflare to use their free models too. Adding a key takes one window: Connect provider, pick the provider, paste the key, Continue. Then pick the model from the list under the message box.

What you need

• OpenCode Desktop, from opencode.ai/download (Windows, macOS and Linux installers). See how to install OpenCode for the desktop app and the CMD or terminal version. OpenCode itself is free; any cost comes from the model provider you connect.
• A free API key, if you want more than OpenCode's own free models. Each of these tutorials gets one: Gemini, Groq, OpenRouter and Cloudflare Workers AI.

Step 1: Try OpenCode's own free models (no key needed)

Open OpenCode and click the model name under the message box. The list starts with the OpenCode group: models marked Free (box 1). Click one, type a question and press Enter. Manage models (box 2) shows the full list.

In Manage models, type free in the search box to see them all. In October 2026 the OpenCode group has eight: Beam Free, DeepSeek V4.1 Flash Free, Flint 40B Free, GLM-5.3-Flash Free, MiMo-V2.6-Flash Free, Nemotron 3 Ultra Free, Nemotron 3.5 Lightning Free and Nemotron 3.5 Super VL Free (box 2). Each switch controls whether a model appears in the picker.

Two things to know about these free models:

• They have a usage limit. After heavy use, if you get a free usage error, just change the model and continue - pick a model from a provider you connected with your own free key (Steps 2 to 4).
• Your data is stored when you use them. OpenCode keeps your data only when you use its own free models, so do not send private code or information to them.

Step 2: Open Connect provider

In Manage models, click Connect provider (box 1 in the picture above). The window lists providers, with a search box at the top (box 1 below):

• Gemini: choose Google (box 2).
• OpenRouter: choose OpenRouter (box 2).
• Groq: type groq in the search box and choose Groq.
• Cloudflare Workers AI: type cloudflare and choose Cloudflare Workers AI.
• Any other OpenAI-compatible API: choose Custom OpenAI-compatible provider (box 3) and enter its base URL - the list of free APIs has them.

Step 3: Paste your API key

The next window asks for that provider's key. For Gemini it asks for your Google API key. Paste the key into the box (box 1) and click Continue (box 2).

Keep the key private: never paste it into a chat message, a shared file or a screenshot.

The Cloudflare Workers AI window asks only for the API key. Cloudflare's API also needs your account ID; if Cloudflare models do not answer, see OpenCode's provider docs.

Step 4: Pick a free model and send a question

Click the model name under the message box again. The provider you connected now has its own group. Type in the picker's search box to find a model quickly - for example free for OpenRouter's :free models, or gemini 3.8 flash for Gemini.

In October 2026, OpenRouter's group in OpenCode lists 14 models marked (free), among them Flint, Gemma 4 26B and 31B, Inkling, Inkling Small, LFM2.5-2.6B, several Nemotron models, North Mini Code and Xing4.0 29B. Pick one, such as Flint (free), type your question and press Enter:

The free limits are the provider's, not OpenCode's - for OpenRouter, 50 free requests a day; for Groq, 1,000 a day on its Free plan models; for Gemini, per model as Google's AI Studio shows.

Free limits by provider

OpenCode is a coding agent: one task can send many requests as it reads files and makes changes, so a daily limit runs out faster than in a chat app. The limits each provider publishes:

When something goes wrong

Words to know

• Provider: the company whose API runs the model - Google, Groq, OpenRouter, Cloudflare.
• Connect provider: OpenCode's window for adding a provider's API key.
• OpenCode Go: OpenCode's paid subscription ($10 a month) for more usage; not needed for the steps above.
• API key: the password that identifies you to a provider. See how to get AI API keys for free.