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

# Adding a custom connector

> Wire any API-key-auth service into Foundry so the assistant can call it.

Beyond the eight [pre-installed connectors](/foundry/connectors/pre-installed), you can wire up almost any service that authenticates with an API key.

<Note>
  **Screenshot coming.** Add-connector dialog.
</Note>

## When you'd want one

* Your team uses a tool that isn't pre-installed — internal CRM, niche API, in-house service.
* You want the assistant to read or write to a system it doesn't know about yet.

## How to add one

1. Open **Settings → Connectors → Add custom**.
2. Give it a name (this is how you'll reference it in chat — keep it short).
3. Paste the API base URL and the API key.
4. Optionally write a one-paragraph description so the assistant knows when to use it.

The custom connector then shows up in the `+` menu alongside the pre-installed ones.

## How it's invoked

Same as a pre-installed connector. The assistant decides based on your prompt, or you can name it explicitly — *"Use my Acme CRM connector to look up this customer"*.

Behind the scenes Foundry signs the request with your key and proxies it; the key never reaches the model.

## Tips

* **Describe it well.** A good description ("queries our internal expense system, accepts an employee ID, returns recent expenses") gives the assistant enough context to use it correctly.
* **Test with explicit calls first.** Once it works reliably with an explicit *"use the X connector"* prompt, the assistant will start picking it on its own.

## Limits

* API-key auth only today. OAuth flows aren't yet supported.
* The custom connector path is best for read-style APIs. Side-effectful writes (sending email, charging cards, deleting data) need extra care — confirm the assistant's intent in chat first.

## Related

<CardGroup cols={2}>
  <Card title="Pre-installed connectors" icon="square-check" href="/foundry/connectors/pre-installed">
    The default eight.
  </Card>

  <Card title="Skills" icon="puzzle-piece" href="/foundry/skills/overview">
    Skills often wrap connectors with structured instructions.
  </Card>
</CardGroup>