# Glossary

> The words the API uses, and what each means.

| Word | Meaning |
|---|---|
| **Conversation** | One exchange on any channel — the main object in the API. The console calls these *Calls*. |
| **Call** | A conversation on the phone (`channel: "phone"`). `POST /v1/calls` places one. |
| **Chat** | A text conversation. `POST /v1/chats` starts one. |
| **Browser voice** | A voice conversation in a web page. Its channel is `voice`; the agent's setting calls it *Browser voice*. |
| **Variable** | A value that fills a `{{placeholder}}` in an agent's instructions or first message. The console calls them *fields*. See [Variables](/guides/variables). |
| **Metadata** | Your own data on a conversation. The agent never sees it; you get it back everywhere. |
| **Context lookup** | Your server, asked who is calling as an inbound call is answered. See [Inbound calls](/guides/inbound-calls). |
| **Webhook** | A message the platform sends your server when something happens. See [Webhooks](/guides/webhooks). |
| **`status`** | Where a conversation stands: `pending`, `active`, `completed` or `failed`. |
| **`disposition`** | How a phone call ended on the phone network: answered, busy, no answer and so on. |
| **`ended_by`** | What ended it: `caller`, `agent`, `operator` (a person in the console), `api`, `transfer` (handed to a person), `system` (a time limit) or `failure`. Null where nothing was ended — a call nobody answered. |
| **`revision`** | A number on every conversation that only goes up. Of two copies, keep the higher. |
| **`finished`** (on a chat turn) | The agent has nothing more to ask. The chat stays open until it is ended. |
| **`mode` and `livemode`** | `mode` is `live`, `test` (the console's own test calls) or `sandbox` (a test key's). `livemode` is false only for `sandbox`. |
| **Test key** | An `ag_test_…` key. Its calls ring nobody and its data stays apart. See [Test mode](/guides/test-mode). |
| **Idempotency key** | Your own id for a request, so sending it again never does it twice. See [Safe retries](/guides/idempotency). |
| **Cursor** | A bookmark for where the next page of a list starts. |
| **Problem document** | How every error is sent: a JSON object with a stable `code`. See [Errors](/errors). |