Build - Voiceflow Documentation

Term	What it is
Playbook	Agentic. Instructions driving toward a goal, calling tools as needed. Use for open-ended work: booking, qualifying, handling a return.
Workflow	Deterministic. Steps drawn on a canvas from the Start chip. Use where the path must be fixed: authentication, IVR menus, scripted onboarding.
Step	One node on a workflow canvas. Named with only the first word capitalised: Message step, API step, Function step.
Tool	Something a playbook can call mid-conversation: functions, API tools, MCP tools, integrations, and the built-in system tools.
Function	Custom JavaScript that runs in Voiceflow’s sandbox and returns through a named path.
API tool	A saved HTTP request an agent can make.
Global prompt	The always-on layer shaping identity, tone and guardrails on every turn.
Instructions	The routing layer: which playbook or workflow handles what.
Trigger	What tells the agent when a playbook or workflow applies. Older material calls this the “LLM Description”; the current name is Trigger.
Behaviour	The model, voice and memory settings an agent runs under.
Function path	One of the named exits a function can return through. Paths are what let a function branch rather than just return a value.
Function variable	An input or output a function declares. Inputs are passed in when it runs; outputs are written back for later steps to read.
API tool variable	An input an API tool substitutes into its request, so one saved request can serve many calls.
API step	Makes an HTTP request from inside a workflow, at a fixed point in the path rather than when a model decides to.
Buttons	Presents a fixed set of choices instead of open input, so the next turn is one of a known few.
Call forward	Transfers a live voice call to another number.
Card	One rich message: an image, a title, a description and optional buttons.
Carousel	Several cards the user can browse through in one turn.
Code	Runs JavaScript inline at one point in a workflow. A function is the reusable form of the same idea.
Condition	Branches a workflow on a rule you write. The Operator step is the model-driven alternative.
Crew	Groups several playbooks so they hand off to each other inside one step, rather than routing through a separate agent. Lower latency than routing out and back.
End	Ends the conversation.
Integration	Calls a third-party service such as Salesforce, Shopify or Zendesk.
Listen	Waits for the user to say or type something before continuing.
Live agent handoff	Hands the conversation to a human.
Message	Says something to the user.
Operator	A silent, model-driven branch. Evaluates conditions in natural language and routes accordingly, producing no output the user sees.
Set	Assigns a value to a variable.
Agent tools	The tools attached to the agent itself rather than to one playbook.
Function tool	A function exposed to a playbook as something it can call.
Global tools	APIs, integrations, MCP servers and functions added at the agent level, so every playbook can use them without adding each one individually.
System tools	Native capabilities built into Voiceflow that need no setup: knowledge base search, web search, buttons, cards, end and call forward. Enabled by a toggle.