# Glossary

Every term this documentation uses that does not mean the obvious thing, or that Sphoro Voice uses more narrowly than the industry does. Defined once, here, so no other page has to stop and explain itself.

| Term | Means |
| --- | --- |
| **Agent** | The configuration a call runs under: languages, prompt, voice, tools, flow, carrier. Not a running thing — the running thing is a call. See [agent reference](https://voice.sphoro.com/docs/agents). |
| **Autonomy** | Who holds the agent's end of a conversation: a model (`agentic`), a person in a browser (`simple`), or a model with named switches (`custom`). Only under `custom` is the `capabilities` block read. See [kinds of agent](https://voice.sphoro.com/docs/agent-types). |
| **Barge-in** | The caller interrupting the agent mid-sentence, and the agent stopping. Configured by words and phrases rather than by volume, so a caller saying "mm-hm" does not cut the agent off. See [conversation behaviour](https://voice.sphoro.com/docs/behaviours). |
| **Campaign** | A journey run over a list of contacts. See [campaigns](https://voice.sphoro.com/docs/campaigns). |
| **Chain** | An ordered list of vendors for one job — transcription, voice or model. The call uses the first that works and falls through on failure. See [vendors](https://voice.sphoro.com/docs/providers). |
| **Direction** | `inbound` or `outbound`. Available in a prompt as `{{call_direction}}`. |
| **DTMF** | Keypad tones. The digits a caller presses, either signalled by the carrier or heard in the audio. See [keypad and IVR](https://voice.sphoro.com/docs/keypad). |
| **Edge** | A way out of a flow node. Four kinds — intent, expression, always, event. See [flows](https://voice.sphoro.com/docs/flows). |
| **End reason** | Which of about thirty ways a call finished. The field to branch on; a call that reached voicemail and one that reached a customer both "complete". See [transfers and endings](https://voice.sphoro.com/docs/transfers). |
| **Endpointing** | Deciding that the caller has stopped speaking rather than merely paused. The first stage of the latency budget. |
| **Extraction** | A typed field pulled out of the transcript after the call — a name, a number, a yes/no, one of a fixed set. See [post-call analysis](https://voice.sphoro.com/docs/post-call). |
| **Filler phrase** | Something the agent says while a tool call is running, so a three-second lookup sounds like thinking rather than a dropped line. |
| **Flow** | Structure *within* one call: named nodes and the edges between them. Contrast with a journey. See [flows](https://voice.sphoro.com/docs/flows). |
| **Function** | Something the agent can do mid-call by calling your API. Also "tool" — the two words are used interchangeably here and mean the same thing. See [tools and functions](https://voice.sphoro.com/docs/functions). |
| **Grounding** | Answering from your documents rather than the model's memory. See [knowledge base](https://voice.sphoro.com/docs/knowledge-base). |
| **Idempotency key** | A header you supply so a retried request cannot place a second call. See [using your API key](https://voice.sphoro.com/docs/authentication). |
| **Journey** | Structure *across* calls and days: dial, branch on the outcome, wait, retry. Contrast with a flow. See [journeys](https://voice.sphoro.com/docs/journeys). |
| **Knowledge base** | A set of documents, chunked and indexed, that an agent can answer from. See [knowledge base](https://voice.sphoro.com/docs/knowledge-base). |
| **Language entry** | One item in an agent's `languages` list, carrying that language's voice, greeting and prompt. The first entry is the one calls open in. See [language and voice](https://voice.sphoro.com/docs/voices). |
| **Mode** | Whether a model is in the loop at all: `conversation`, `keypad`, `normal` or `webrtc`. See [kinds of agent](https://voice.sphoro.com/docs/agent-types). |
| **Persona** | The idea an agent deploys — prompt, voice, knowledge, flow — separated from the telephone it deploys on. See [personas](https://voice.sphoro.com/docs/personas). |
| **Project** | A cost centre inside your account, optionally with a monthly budget. Not a tenant and not an isolation boundary. See [projects](https://voice.sphoro.com/docs/projects). |
| **Suppression list** | Your do-not-call list. Checked before every outbound call, and added to automatically when a caller asks not to be called again. See [compliance](https://voice.sphoro.com/docs/compliance). |
| **Turn** | One exchange: the caller speaks, the agent answers. The unit the latency budget is measured over. |
| **Voice line** | A fixed piece of speech rendered once and replayed, rather than synthesised on every call. See [voice lines](https://voice.sphoro.com/docs/voice-lines). |
| **Workflow** | The work that happens after the conversation — book, update a CRM, send an email. See [workflows](https://voice.sphoro.com/docs/workflows). |

## Where these appear

Most of the terms above are fields on an agent or a call, so the fastest way to attach a name to a thing is to read one of each and look:

**Shell**

```bash
curl -s https://voice.sphoro.com/v1/agents/$AGENT_ID \
  -H "Authorization: Bearer $SPHORO_API_KEY"

curl -s https://voice.sphoro.com/v1/calls/$CALL_ID \
  -H "Authorization: Bearer $SPHORO_API_KEY"
```

## Two pairs that get confused

Both pairs sound like synonyms and are not, and mixing them up is the source of most of the "I configured it and nothing happened" reports we see.

|  | Within one call | Across many calls |
| --- | --- | --- |
| Structure | **Flow** — which part of this conversation you are in | **Journey** — which call in the sequence you are on |
| Grouping | **Agent group** — settings shared by a fleet of agents | **Project** — what the calls cost, and to whom |