# Scope a key or user

A scope is the set of operations a credential can call. It selects from the operations the environment exposes. A client sees only the operations in the scope of the credential it connects with: they are the only ones in the MCP tool list and in the results of `search_operations`.

## Change the scope

To change what a key or user can call:

1. In the portal, go to [**Agent Gateway**](https://auth.faustine.ai/go?to=%2Fintegrations%2Fagent-gateway) and select your gateway.
2. Select the **Access** tab, then **API keys** or **Users**, and select the credential.
3. In the **Scope & access** section, select a **Preset** or select operations in the list.
   - **Everything (\*)** covers every exposed operation, including the ones you expose later.
   - **All reads** selects every read operation that is exposed now.
   - **None** clears the selection so you can select operations one by one.
4. Select **Save changes**.

For a user, the change applies to existing sessions on their next call. A call to an operation outside the scope is refused with `scope`.

## Make a credential read-only

In **Scope & access**, turn on **Read-only** and save. Every write operation in the scope is refused with `read_only`. The operations stay in the scope, so turning the switch off restores them.

Read-only is independent of confirmation. Use it for a reporting client, or for the first weeks of a rollout.

## Restrict the connections

When an API has more than one connection in the gateway, the credential's page has an **Allowed connections** section. Select the connections of each API the credential can use. With nothing selected, the credential can use every connection.

Use this to give a partner a key that reaches only their own deployment. See [Routing: fixed, dynamic and fan-out](https://docs.faustine.ai/agent-gateway/routing/) for how a call picks among the allowed connections.

## What the credential reaches

The top of **Scope & access** shows what the credential can call once read-only and its confirmation choice apply. An operation that requires confirmation is hidden from a credential set to **Refuse**, even when it is in the scope. See [Confirmation](https://docs.faustine.ai/agent-gateway/confirmation/).

## Troubleshooting

| Symptom | Cause | Fix |
| --- | --- | --- |
| A call is refused with `Denied (scope): This key is not scoped for "…"` | The operation is not in the credential's scope. | Add it under **Scope & access**. |
| An operation in the scope does not appear in the client | The operation is hidden in the environment, or it requires confirmation and the credential is set to **Refuse**. | Expose it in the **Operations** tab, or change the credential's **Confirmation** choice. |
| A key lost operations after an API was removed from the gateway | Removing an API removes its operations from every scope. | Add the API again and select the operations. |

## Next steps

- [Choose which operations are exposed](https://docs.faustine.ai/agent-gateway/choose-operations/): hide an operation from every credential.
- [Set how a credential confirms writes](https://docs.faustine.ai/agent-gateway/set-confirmation/): decide what happens on operations that require confirmation.
- [Limits and quotas](https://docs.faustine.ai/agent-gateway/limits/): rate and quota limits per credential.