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

# End calls and calculate

> Set up the End Call and Calculator tools and attach them to the right nodes.

Create built-in tools in **Tools**, then select them in the **Tools** field of each conversation node that needs them. Save and publish the workflow after testing. These tools do not need an external HTTP endpoint.

## Set up End Call

1. Create a tool with category **End Call** and give it a descriptive name.
2. Set **Description** to explain when to disconnect. For example: “End after the caller says goodbye or asks to end the call. A thank-you alone does not mean the conversation is over.”
3. Choose a **Goodbye Message**: **No Message**, **Custom Message**, or **Pre-recorded Audio**. Enter text or choose a library recording for the latter two options. Prerecorded playback requires a supported cascade path; see [Recordings](/guides/recordings.md).
4. Optionally enable **Capture End Call Reason** and provide **Reason Description** instructions. The generated reason is recorded as a disposition and call tag; coordinate the values with [outcome extraction and mapping](/guides/outcomes.md).
5. Save the tool and attach it to the nodes that should be allowed to end the call. Include the end conditions in the node prompt.
6. In a controlled test, check both a genuine goodbye and a mid-conversation “thank you.” Confirm the call ends only on the intended path, any goodbye plays, and the run records the expected outcome.

An **End Call node** ends a planned graph path. The **End Call tool** allows the model to decide to end while another node is active. Choose the mechanism that matches your conversation design.

## Set up Calculator

1. Create a **Calculator** tool and set its name and description, for example “Calculate totals from amounts the caller provides; do not estimate arithmetic.”
2. Save it and attach it to the relevant Start Call or Agent nodes.
3. In the node prompt, specify which amounts, units, and rounding rules apply to your task.
4. Test an expression with a known answer, such as `(12.5 * 4) + 3`, which equals `53`. Inspect the tool invocation and result in the run, then check the agent's spoken answer.

Supported arithmetic includes `+`, `-`, `*`, `/`, `**`, `%`, and parentheses. The calculator evaluates arithmetic; it does not look up current exchange rates, taxes, or prices. Supply those inputs from an appropriate source when your task requires them.

## Other built-in actions

Use [Phone menus and hold](/guides/phone-menus.md) for **Press Phone Keys**, and [Call transfers](/guides/transfers.md) for **Transfer Call** and **Transfer To Agent**. A disabled **Integration (Coming Soon)** choice does not provide a working third-party connector.


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