# Connect Goose to Tesselith

> Add Tesselith to Goose as a remote extension and let your local agent draft and schedule social posts.

Canonical: https://tesselith.com/ai-agents/goose

**Before you start:** You need Goose (desktop or CLI) and a Tesselith workspace on Pro, Team or Agency (every new workspace starts with a 14-day Pro trial) with at least one channel connected.

## Quick setup

```yaml
extensions:
  tesselith:
    name: Tesselith
    type: streamable_http
    uri: https://api.tesselith.com/mcp
    enabled: true
    timeout: 300
```

Or in the desktop app: Extensions → Add custom extension → Streamable HTTP.

## Step by step

### 1. Add the extension

In Goose desktop, open the sidebar, choose Extensions, click Add custom extension, set the type to Streamable HTTP and paste the URL. In the CLI, run goose configure, choose Add Extension, then Remote Extension (Streamable HTTP).

```text
https://api.tesselith.com/mcp
```

### 2. Sign in

Goose registers itself with Tesselith automatically and opens your browser. A Tesselith window opens. Sign in, pick the workspace, untick anything you don't want the agent to do, and click Allow access.

### 3. Check it's enabled

Tesselith shows as enabled under Extensions. Ask Goose to list the Tesselith tools.

### 4. Ask Goose

Ask it to draft and queue posts. It works through Tesselith's tools and links to each post.

## With an API key

To use a key, add an Authorization header when adding the extension: Request Headers in the desktop app, or answer yes to "add custom headers?" in goose configure. In Tesselith, open Settings → Developers, create an API key and tick only the scopes the agent needs. Keys start with tsl_live_ and are shown once, so store it in your password manager or a secret store.

```text
Authorization: Bearer tsl_live_…
```

## Troubleshooting

- **Connection fails:** The extension type is SSE or stdio. Choose Streamable HTTP.
- **Tool calls time out:** Raise timeout on the extension.
- **Sign-in callback blocked:** Set GOOSE_OAUTH_CALLBACK_PORT to a fixed port your firewall allows.

## Questions people ask

### Does Goose need an API key?

No. Goose supports Tesselith's browser sign-in; use a key only for unattended runs.

### Can Goose upload my local images?

Tesselith's MCP server fetches media from public HTTPS URLs. Host the image somewhere public first, or upload it in Tesselith.

Docs: https://goose-docs.ai/docs/getting-started/using-extensions

---
Tesselith · https://tesselith.com · Full site index: https://tesselith.com/llms.txt