> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flowra.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Multi-tenant basics

> Use x-username so each end user gets isolated connected accounts and runs.

**Goal:** Link Slack (or another toolkit) for two different end users without mixing tokens.

In the dashboard, the same idea is the **End user** switcher — see [External users switcher](/product/external-users). On the API, you pass that identity as **`x-username`**.

## Prerequisites

* API key for your project — [Authentication](/authentication)
* An auth config for the toolkit — [Auth configs](/guides/auth-configs)

## Steps

<Steps>
  <Step title="Pick stable usernames">
    Choose one username per end user in your product (for example `customer_alice`, `customer_bob`). Use the **same string every time** for that person — in `x-username`, when you create them in the dashboard, and when you link accounts.
  </Step>

  <Step title="Link for alice">
    ```bash theme={null}
    curl -X POST "https://flowra.dev/api/v1/connected_accounts/link" \
      -H "x-api-key: YOUR_API_KEY" \
      -H "x-username: customer_alice" \
      -H "Content-Type: application/json" \
      -d '{
        "toolkitSlug": "slack",
        "authConfigId": "YOUR_AUTH_CONFIG_ID"
      }'
    ```

    The response includes an OAuth **URL**. Open it in a browser, approve access as Alice’s Slack workspace, then return to your app. If `customer_alice` did not exist yet, Flowra creates that external user.
  </Step>

  <Step title="Link for bob">
    ```bash theme={null}
    curl -X POST "https://flowra.dev/api/v1/connected_accounts/link" \
      -H "x-api-key: YOUR_API_KEY" \
      -H "x-username: customer_bob" \
      -H "Content-Type: application/json" \
      -d '{
        "toolkitSlug": "slack",
        "authConfigId": "YOUR_AUTH_CONFIG_ID"
      }'
    ```

    Complete OAuth with **Bob’s** Slack workspace (a different account/workspace than Alice’s).
  </Step>

  <Step title="Run in the right context">
    When you execute a workflow or tool for Alice, always send `x-username: customer_alice` (same for Bob).

    Omit the header only when you intentionally want the **project default** user.

    The same header also scopes [Knowledge](/guides/knowledge) and [Table](/guides/table) collections per end user — not only Slack connections.
  </Step>
</Steps>

## Verify

* List connected accounts once with `x-username: customer_alice` and once with `customer_bob` — each list should show that user’s Slack link, not the other’s.
* Or in the dashboard: switch **End user** to each username under [Connection](https://flowra.dev/dashboard/connection) and confirm separate rows.
* Execute a Slack-backed tool or workflow for Alice; confirm Bob’s workspace is never used.

## Next

* Full model and scoping matrix: [Multi-tenancy](/guides/multi-tenancy)
* Dashboard switcher: [External users switcher](/product/external-users)
* [Connect an account](/recipes/connect-an-account)