> ## Documentation Index
> Fetch the complete documentation index at: https://thebettercontextapp-davis-web-resource.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

> Connect providers locally and link your cloud API key

## Local provider auth (btca-server)

btca reads credentials from OpenCode's auth storage:

* macOS/Linux: `~/.local/share/opencode/auth.json`
* Windows: `%APPDATA%/opencode/auth.json`

Supported providers:

* `opencode` (API key)
* `openrouter` (API key)
* `openai` (OAuth, no API keys)
* `github-copilot` (OAuth device flow)
* `openai-compat` (optional API key)
* `anthropic` (API key)
* `google` (API key or OAuth)

Environment variable overrides:

* `OPENCODE_API_KEY` (for provider `opencode`)
* `OPENROUTER_API_KEY` (for provider `openrouter`)

### Connect or disconnect

```bash theme={null}
btca connect
btca disconnect
```

`btca connect` performs OAuth for `openai` and `github-copilot`, prompts for API keys when
required, and falls back to `opencode auth --provider <provider>` for other providers.

For `github-copilot`, btca uses device flow OAuth and opens a browser prompt to complete
the sign-in.

For `openai-compat`, `btca connect` also collects the required provider details:

* **Base URL** (required): the root URL of your OpenAI-compatible server. The AI SDK appends its own
  endpoint paths, so btca must know the base URL to send requests to the correct host.
* **Provider name** (required): the identifier the AI SDK uses to namespace requests for this
  OpenAI-compatible provider.
* **Model ID** (required): the model to use for requests; stored in `btca.config.jsonc` as `model`.
* **API key** (optional): only if your server requires authentication; stored in OpenCode auth.

## Cloud auth (btca remote)

Remote commands require an API key stored at:

```
~/.config/btca/remote-auth.json
```

Example:

```json theme={null}
{
	"apiKey": "btca_xxxxxxxxxxxx",
	"linkedAt": 1706000000000
}
```

Use the CLI to link:

```bash theme={null}
btca remote link
```

All cloud requests send:

```
Authorization: Bearer <apiKey>
```