> For the complete documentation index, see [llms.txt](https://docs.ui-color-palette.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ui-color-palette.com/mcp/authentication.md).

# Authentication

How to authenticate with the MCP server to access community tools

Palette generation tools work without any credentials. Community tools — publishing, updating, deleting, or listing your own palettes — require a valid UI Color Palette account.

## How it works

The server implements **OAuth 2.0** with dynamic client registration. The authorization server is Supabase, proxied through the MCP worker so that MCP clients see a single issuer.

| Endpoint            | Path                                      |
| ------------------- | ----------------------------------------- |
| Discovery           | `/.well-known/oauth-authorization-server` |
| Client registration | `/oauth/register`                         |
| Token exchange      | `/oauth/token`                            |
| MCP                 | `/mcp`                                    |

MCP clients that support OAuth 2.0 (Claude Desktop, Cursor, etc.) handle the full flow automatically — you just sign in when prompted.

## Bearer token

If your client does not handle OAuth automatically, you can pass an access token directly:

```http
Authorization: Bearer <your-access-token>
```

The token is read from the `Authorization` header on the `/mcp` request and stored in durable state for the duration of the session.

## Which tools require authentication

| Tool                          | Auth required |
| ----------------------------- | ------------- |
| `get_palette`                 | No            |
| `get_color_system`            | No            |
| `create_color_harmony`        | No            |
| `extract_dominant_colors`     | No            |
| `generate_code`               | No            |
| `generate_colors_from_prompt` | No            |
| `preview_palette`             | No            |
| `list_published_palettes`     | No            |
| `list_my_published_palettes`  | **Yes**       |
| `get_published_palette`       | No            |
| `publish_palette`             | **Yes**       |
| `update_published_palette`    | **Yes**       |
| `share_published_palette`     | **Yes**       |
| `unshare_published_palette`   | **Yes**       |
| `unpublish_palette`           | **Yes**       |

When a tool requires authentication and no token is present, the server returns:

```json
{ "error": "Authentication required. Please sign in via OAuth to use this tool." }
```