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

# Env and mock tools

First [connect your Retell agent](/docs/integrations/retell/connect).

## Pass data to a test

If the agent normally receives dynamic variables, put their test values in
the test's `## Env` section:

````markdown theme={"system"}
## Env

```json
{
  "retell_dynamic_variables": {
    "clinic_name": "Oak Street Clinic",
    "caller_name": "Alex Morgan"
  }
}
```
````

Use the exact variable names that the agent reads. Values must be strings.
Do not use names starting with `egma_`; that prefix is reserved. Egma passes
these variables to text and web-call simulations.

## Mock tool responses

Add a [Mock tools section](/docs/platform/tests/mock-tool-responses) to a test to return a
controlled response for a selected custom tool. Use the exact tool name and
the response shape your agent expects. Retell integrations do not need an
Egma SDK in your backend for this.

Only the tools named in the test are mocked. Other tools still run against
their real backend. Retell's built-in actions, such as call transfer, SMS,
digit pressing, and built-in booking, are not replaced by custom-tool mocks.
These mocks do not replace MCP tools either.

<Warning>
  Web-call runs with mock tools create a temporary Retell agent version.
  During that run, this version is **Latest Created**. Keep real phone numbers
  and environment tags pinned to a serving version or **Latest Published**.
  An unset phone-number version also uses **Latest Created**. Egma does not
  change your production routing for you.
</Warning>