Build and run a simple summarizer with a Start block and an Agent block.
You need a workspace where you can edit and run workflows, and access to a chat model. Configure model credentials if prompted. Model calls can incur usage charges.
Start in Chat
Select New chat and ask:
Build a workflow that summarizes a product update in one sentence. Use a Start block and an Agent block, and open it beside this chat.
Inspect the blocks and resolve any missing model credentials before running. You can ask Sim to refine the workflow or edit it directly in the side panel. See Workflows in Chat.
Build it in the workflow builder
To configure the same pattern yourself, follow these steps. This example keeps the update in the Agent's prompt; connection tags let you pass changing inputs later.
Create a workflow
Click + beside Workflows in the sidebar. The new workflow contains a Start block.
Open Toolbar, search for Agent, and click it to add the block. Connect Start's output handle to Agent's input handle if they are not already connected.
Give the Agent a task
Select Agent to open its fields in Editor. Choose an available chat model in Model. Rename the block Summarize update using the pencil beside its name.
In Messages, set the message role to User and paste:
Summarize this update in one sentence:
We launched the new dashboard on Monday. Customers can now filter
reports by team and export them as CSV. The mobile layout is still
in progress.Run and check the result
Click Run. Expand Logs at the bottom of the builder, select Summarize update, and open Output.
The content field contains the summary. It should look like this; the wording may vary:
The new dashboard adds team filters and CSV exports, with the mobile layout still in progress.
Change the update in Messages and run it again to see the result change.
If the run fails
Select the failed block in Logs and read its error. Check the selected model and its credentials, then run again. See Logs and debugging for more help.
Next steps
- Build a research agent: Add web search tools and structured output.
- Pass data between blocks: Use references such as
<start.input>. - Deploy your workflow: Make it available through an API, chat, or MCP server.
