--- title: Flow editor description: "The Flow section of a flow agent: a canvas of nodes and edges, a toolbar, a settings panel for variables and global tools, and Save." --- Flow agents The flow editor is where a flow agent's conversation is designed. It replaces the three prompt fields of a single-prompt agent with a canvas: each **node** carries its own instructions, and each **edge** decides when the conversation moves from one node to the next. It lives under **Flow** in the agent workspace, at `/agents/edit//flow`. :::note[Only flow agents have it] The **Flow** section appears only for agents created as a **Conversation Flow**. A single-prompt agent cannot be switched to a flow; create a new agent instead. See [Choosing a prompt type](/build/choosing-a-prompt-type). ::: ![The Flow section: Start Call, a Prompt node, a Webhook node, a Transfer call node and End Call, joined by labelled edges.](/media/build/flow-canvas.webp) ## How it works A new flow agent opens with 3 nodes already on the canvas: **Start Call**, one **Prompt** node and **End Call**. A conversation always begins at **Start Call**, follows edges whose conditions are met, and ends when it reaches an **End Call** node, when a **Transfer call** node hands the call over, or when a tool such as [End Call](/build/tools/end-call) fires. At every node the agent is given the node's own instructions on top of the agent's general settings (language, voice, first message rules, [Advanced](/build/speech-pipeline/turn-detection) tuning). It talks to the person until one of the outgoing edges' conditions is satisfied, then moves on. The prompt of a flow agent is therefore the sum of its nodes, read one at a time, not one long text. ## The canvas - **Drag** a node to move it. Positions are saved with the flow. - Every node except **End Call** has a **+** handle at its bottom. Choosing it opens **Add node**, which lists the node types and connects the new node to the one you started from. See [Nodes](/build/flow-agents/nodes). - Choosing a node opens its editor in a panel on the right. **Save Changes** applies the panel to the canvas; **Cancel** discards it; **Delete Node** removes the node and its edges. - Choosing an edge's label opens **Configure Edge Connection**. See [Edges and conditions](/build/flow-agents/edges-and-conditions). - The mini map at the bottom right shows where you are in a large flow. Changes made in a panel are held in the editor until you choose **Save** at the top of the page. The indicator at the right end of the toolbar reads **Flow Saved** when nothing is pending. ## The toolbar | Control | What it does | |---|---| | **Zoom Out**, **Zoom In** | Change the canvas scale. Scrolling on the canvas does the same. | | **Fit View** | Zooms and pans so every node is visible. | | **Fullscreen** | Expands the canvas to the whole browser window. Press Escape to leave. | | **Auto Layout** | Rearranges the nodes top to bottom along their edges. Useful after generating or after adding branches by hand. | | **Call** | Starts a browser test call with this flow. Same as **Call** under **Testing**. | | **Generate** | Opens a menu with **Custom Instructions** and **Enhance Current Flow**. See [Generate a flow](/build/flow-agents/generate-a-flow). | | **Global Tools** (sliders icon) | Opens the **Settings** panel with **Variables** and **Global Tools**. | | **Flow Saved** (tick icon) | The save state of the flow. | ![The main toolbar: Call, Generate, Global Tools and the save state. Zoom, Fit View, Fullscreen and Auto Layout sit in a second group at the bottom left.](/media/build/flow-toolbar.webp) ## The Settings panel The sliders icon opens a panel with two sections. **Variables** lists the predefined dynamic variables you can write into any node's instructions, each with a **Copy** button: `{{now}}`, `{{date}}`, `{{time}}`, `{{month}}`, `{{day}}`, `{{year}}`, `{{call_from_number}}`, `{{call_to_number}}` and `{{sip_headers}}`. Below them the panel lists the custom variables it finds in your flow; write `{{variable_name}}` in any prompt to create one. Variables extracted by a **Prompt** node's **Extract** tab also become available to later nodes. See [Dynamic variables](/build/dynamic-variables). **Global Tools** holds the tools available at every node of the flow. It works like the **Tools** section of a single-prompt agent: **Add Tool** opens the same picker, and each tool has **Edit** and **Remove**. A **Prompt** node can add tools of its own on its **Tools** tab and can opt out of the global ones with **Include Global Tools**. See [Tools overview](/build/tools/overview). ![The Settings panel, with Variables and Global Tools.](/media/build/flow-settings-panel.webp) ## Saving and versions **Save** at the top of the page writes the whole flow as a new version of the agent, the same as saving **Settings** does. The version counter in the sidebar moves and the change is listed under **Versions**, so a flow can be compared and rolled back like any other change. See [Versions](/test-and-improve/versions). Leaving the page with unsaved panel changes discards them. ## Behaviour and limits - A flow needs exactly one **Start Call** node. It cannot be deleted; the **Add node** menu does not offer another. - A node with no outgoing edge keeps the conversation at that node until the call ends by other means. Give every **Prompt** node a way out, even if it is a single **None (Always)** edge to **End Call**. - Everything outside the flow (voice, language, [Outcomes](/build/outcomes), [Advanced](/build/speech-pipeline/turn-detection), [Widget](/deploy/widget-and-embed/widget-designer)) is configured the same way as for a single-prompt agent. - Testing works the same too: **Chat** and **Call** under **Testing** run the flow. The [Launch Checklist](/test-and-improve/launch-checklist) refuses to publish a flow with no start node. ## Related - [Nodes](/build/flow-agents/nodes) - [Edges and conditions](/build/flow-agents/edges-and-conditions) - [Generate a flow](/build/flow-agents/generate-a-flow) - [Choosing a prompt type](/build/choosing-a-prompt-type) - [Tools overview](/build/tools/overview)