# Agent Builder Guide ## Overview The Agent Builder is the visual editor where you design and build agents by connecting blocks together on a canvas. Each block is a single action — like generating text, calling an API, or processing data — and you wire them together to create automated workflows. **URL:** [platform.agpt.co/build](https://platform.agpt.co/build) ## The Builder Interface When you open the builder, you'll see: * **Canvas**: The main workspace where you place and connect blocks * **Blocks Menu**: A panel on the left-hand side where you browse and search for blocks * **Save Button**: Save your agent with a title and description ## Working with Blocks ### Types of Blocks Blocks fall into three categories: | Type | Description | | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Input Blocks** | Define what information the agent needs when it runs. These become the input fields users fill in when starting a task. Types include text inputs, file inputs, and more. | | **Action Blocks** | Perform operations — AI text generation, image creation, API calls, data processing, and hundreds of integrations with external platforms. | | **Output Blocks** | Define what the agent returns as its result. These become the visible output when a task completes. | Input and output blocks define the **schema** of your agent — they determine what users see when running the agent. All other blocks inside the agent are internal and not exposed to the user at runtime. {% hint style="info" %} There is also a special type of input block: **Trigger Blocks**. These allow your agent to be activated by external events via webhooks rather than manual input. See [Scheduling & Triggers](/docs/platform/using-the-platform/scheduling-and-triggers.md) for details. {% endhint %} ### Adding Blocks 1. Open the **Blocks menu** on the left-hand side of the builder 2. Browse categories or use the search bar to find a specific block 3. Click on a block to add it to the canvas There are hundreds of blocks available, integrating with many platforms and services. ### Connecting Blocks Blocks have **input pins** and **output pins**. Pins are typed — they handle specific data types like text, numbers, files, and more. To connect blocks: 1. Click on an **output pin** of one block 2. Drag to an **input pin** of another block (or simply click the output pin, then click the input pin) 3. A **connection line** will appear between the two pins When the agent runs, data flows along these connections. This is visually represented by a **coloured bead** that slides along the connection line from the output pin to the input pin. ### Configuring Blocks Many blocks have settings you can configure directly on the block. For example: * The **AI Text Generator** block lets you choose which language model to use * **Integration blocks** may require credentials (see [Integrations & Credentials](/docs/platform/using-the-platform/integrations-and-credentials.md)) * Some blocks allow you to hardcode values on their input pins instead of connecting them to other blocks If a block requires a credential you haven't connected yet, a **credential bar** will appear prompting you to add it (via OAuth, API key, or username/password depending on the service). ## Saving Your Agent To save your agent: * Press **Ctrl+S**, or * Click the **Save button** in the builder When saving, you can provide a **title** and **description** for the agent. This is a local save to your personal library. For publishing to the public marketplace, see [Publishing to the Marketplace](/docs/platform/using-the-platform/marketplace.md#publishing-an-agent). {% hint style="info" %} There is currently no draft vs. saved state — saving an agent immediately updates it in your library. {% endhint %} ## Navigating Back to Your Library After saving, click the **Agents** button in the navigation bar to return to your library and find your agent. ## Editing an Existing Agent To open an existing agent in the builder: 1. Go to your **Agent Library** (click **Agents** in the nav bar) 2. Click on the agent you want to edit 3. Click the **three dots** menu (⋯) on the far right-hand side of the screen 4. Select **Edit Agent** This will open the agent in the builder with all its existing blocks and connections. ## Error Handling When a block fails during execution, it produces data on its **error pin**. As the agent creator, you decide how to handle errors: * **Surface the error**: Connect the error pin to an output block so the error is returned as the agent's result * **Handle gracefully**: Connect the error pin to other blocks that provide fallback behaviour, ensuring the agent continues working even when individual blocks encounter problems ## Tips * **Name your input and output blocks clearly** — these names become the labels users see when running your agent * **Test incrementally** — save and run your agent frequently as you build to catch issues early * **Use the search** in the blocks menu to quickly find what you need among hundreds of available blocks * **Check the pin types** — connections only work between compatible pin types --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://agpt.co/docs/platform/using-the-platform/agent-builder-guide.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.