Connections
How Sauna links to the apps you already use.
Connections is where Sauna's access to the outside world lives. Open the profile avatar, tap Settings, and the Connections tab is the first thing on the list: every app you've wired up, every app you could, and the tools to add anything the library doesn't already cover.
Where most chat tools only let you link one account for each app, Sauna lets you connect as many as you need. A work Gmail and a personal Gmail both sit under one Gmail row, each with its own reconnect and remove controls.
Three ways to get something hooked up: pick from the built-in library, hand-roll a connection with an API key or MCP Server URL, or tell Sauna what you want in chat and let it set things up for you. The auth pop-up flow itself is described under Chat Input Box → Connections; this section focuses on the Settings tab and the chat path.
Library
The library is two lists: the apps you've already connected and the catalogue of everything you could connect.
Your Connections sits under the Connections row in the Settings nav. Each app is a card with its logo, name, and connected-account count. Expand a card to see each linked account in a row. Each linked account has its own Reconnect and Remove buttons, and a + Add New at the bottom hooks up another account.
Hit + Add a Connection in the top-right to open the catalogue.
The catalogue is thousands of apps behind one search bar. Type into Search available apps and the list filters as you type. Superhuman and Zapier lead the list because they're built-in MCP servers. Tap Connect on any row to start the auth flow. The Add MCP or API tile at the top is the escape hatch for anything that isn't on the list.
Custom integrations
When a service isn't in the library, you bring it in yourself. The Add MCP or API tile opens a small form with two tabs.
The API tab is for services you talk to over HTTP with a key. Give the connection a name (e.g. OpenAI, Anthropic, My API), optionally a description (e.g. Search academic papers, manage projects), one or more domains (api.example.com; the first becomes the base URL), and then one or more credentials. The default is a Bearer token; the dropdown also covers header-based keys, query-param keys, and basic auth. Need more than one credential (an API key plus a secret, say)? Hit + Add credential to stack another row. Save, and Sauna holds the credentials and injects them into any request it proxies to that domain.
The MCP Server tab takes a URL (https://mcp.example.com), an optional name, and an Advanced settings block for OAuth Client ID and OAuth Client Secret. Helper text under Advanced: Pre-registered OAuth credentials. Leave blank for servers that support dynamic client registration. Hit Connect and Sauna probes the server. OAuth servers redirect you out to authorize and drop you back on return. API-key servers flip the form to a credentials step. Servers that don't need auth save straight through.
Connect via chat
Tell Sauna what you want in chat and let it set things up for you.
Say something like "I have an integration that you guys don't support. How can I do this?" and Sauna splits the answer into two options: MCP server if the service publishes one, or an API key setup with base URL and auth header. It asks which kind you've got. Reply API key and it follows up with Which service? (name + docs URL if handy), Base API URL, Auth header format. If you just give it the service name, Sauna hunts down the rest itself.
Once Sauna has enough to work with, it opens a small form card inside the chat with the fields pre-filled from what you told it, so all you do is paste the key and save. The connection that lands is the same record you'd get from the Settings add form.
