Use your existing AI subscriptions

You don't need a new AI subscription to use Granular. Sign in with a Claude or ChatGPT plan you already pay for, paste your own API key, connect a service like OpenRouter, or let Granular run the AI for you. Your files stay ordinary files on your computer, and you can keep using your other tools on them.

Do I need a new AI subscription?

No. Granular needs an AI model behind it, but it can use one you already have. All of these live in the connection menu (the button under the message box that shows your current connection's name, or Connect an agent), under Add your AI agent:

• Sign in with Claude. Use your paid Claude Pro or Max plan. A free Claude account won't work. Nothing to install.
• Sign in with Codex. Use a paid ChatGPT plan through OpenAI's Codex. See Connect Codex.
• Add by API key. Paste an Anthropic, OpenAI or Gemini key and pay that company directly. (An API key is a long password that lets software use a company's AI.) See Connect Gemini.
• Add custom provider. Connect an AI service such as OpenRouter with its web address and your key. It can be any service that speaks Anthropic's or OpenAI's format, including a model running on your own computer. See Add a custom AI provider.
• Granular Hosted. No AI account at all? The AI Add-on runs the models for you and you pay in credits. See Granular Hosted models.

New and no AI plan? Start free

When you first set up Granular with no AI connection, you'll see No AI subscription? Start with free credits. Click Start free to get a one-time bundle of hosted AI credits. You need a free Granular account, and no card. The credits are one bundle per account and computer.

For every option in detail, see Connect an AI model.

Can I mix engines, like a Claude boss with a Codex worker?

Yes. An engine is the AI program that does the work: Claude, Codex or Gemini. When a boss session hands out work, each worker can run on its own engine and its own account. (A boss is a session that splits a job and hands pieces to worker agents. See Boss and worker agents.)

1. Make sure each account you want to use is connected in the connection menu.
2. In the boss session, say which engine or account each worker should use, for example: "Start a worker on Codex to write the tests."
3. Workers you don't specify use the same engine and account as the boss.

Good to know:

• If you name an account the boss can't find, it stops and lists the real options. It never quietly swaps in another account, because the account decides who pays.
• A Codex worker needs your Codex sign-in, and a Gemini worker needs your Gemini key. Granular Hosted models, including its GPT and Gemini models, run through the Hosted account instead.

Do my existing connectors work?

A connector lets your agent use another app, such as Gmail, Notion or Slack. All of them live in Settings → Connectors, and they come in two broad kinds.

Connectors you add in Granular are the apps you connect from Discover apps (Gmail, Slack, Google Drive and 1,400+ more), Granular's built-in connectors (such as Notion, GitHub or Stripe) and your custom connectors. They work with Claude, Codex and Gemini, and on Granular Hosted too. See Connectors.

Connectors from your other AI tools show under the This computer tab: the ones you set up on claude.ai, servers you added in Claude Code, and Codex's or Gemini's own. Your Claude account's connectors belong to your Claude login, so:

• They work in chats signed in with Claude.
• On Codex or Gemini, they work only if you switch on the Bridge for them, which asks your own Claude to do the work. See Bridge to every model.
• They don't work on Granular Hosted, because Hosted doesn't use a Claude login. If you rely on one there, connect the same app from Discover apps instead.

See This computer connectors.

Each connector has one switch. Turn it on or off in Settings, or from the + button under the message box, under Connectors. It's the same switch either way, so it applies to every chat. See Connectors in chat.

One thing to know about Gemini: Google is stricter than other AI companies about how a connector describes its tools. Granular adjusts those descriptions for connectors that run on your computer, including the built-in Notion connector, so they work with Gemini. A remote connector added by web address can still be refused. If a Gemini chat fails with "Google rejected this request (INVALID_ARGUMENT)", switch off the connector the message names, or the one you added most recently, and send again. Remember the switch applies to every chat.

Where do my API keys go?

It depends on what the key is for:

• A key that powers Granular's agents (Anthropic, OpenAI, Gemini or a custom provider) goes in the connection menu, under Add your AI agent.
• A key your project uses, such as a payment or email service your website calls, goes in Granular's built-in Key Vault, in Settings → Key Vault.

A Vault key reaches a session only when all of this is true:

1. The entry is turned on for sessions.
2. It has a variable name (the name your project's code looks for, like STRIPE_SECRET_KEY).
3. It is allowed for this project, or for all projects.

The variable name can be anything. It doesn't need a special ending or prefix. If you add or change a key, start a fresh session (or reload when Granular offers) so the terminal picks it up. See Vault for API keys and secrets.

Never paste a key into the chat or into a plain file. The Vault and the connection menu keep keys encrypted.

Does it replace Cursor, VS Code or ChatGPT?

No, it works alongside them. Each Granular session works in an ordinary folder on your computer. You can open that same folder in Cursor, VS Code or any other app at the same time, and changes show up in both. You can keep chatting in ChatGPT or Claude on the web too. If you sign in to Granular with those same accounts, your usage comes out of the same plan.

One thing to keep in mind: if Granular and another tool edit the same file at the same moment, the last save wins. Let one finish before the other starts on that file.

Is my work locked in?

No. What you make is yours, in plain formats:

• Your files are ordinary files in folders you chose on your computer. Uninstalling Granular leaves them where they are.
• Your digital brain is a folder of plain Markdown notes (simple text files), readable in any text editor. See Digital brain.
• Your AI accounts stay yours. Granular signs in with them; it doesn't replace them.

Some things live inside Granular on this computer rather than in your folders: your chat history, your connections and your Vault keys. They don't upload to your Granular account, so on a new computer you connect them again.

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