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What a workflow is

A workflow is a graph of nodes that LangWatch runs from an Entry point to an End node. Each node takes named inputs, produces named outputs, and an edge connects an output of one node to an input of the next. Workflows live under Build, Workflows in the LangWatch sidebar. For example, the workflow below answers a support question with a prompt, checks the answer length in a Python node, and asks an LLM judge whether the answer addresses the question. The End node collects the answer, the length check and the verdict.
The editor autosaves every change. You save a numbered version when you evaluate or publish, and you can restore any earlier version.

When to use a workflow

Building a workflow

Create a workflow, configure each node, run it and read the results.

Workflow as evaluator

Publish a workflow so it scores outputs like a built-in evaluator.

Workflow as agent

Use a workflow as the target of your agent tests.

Prompts in workflows

Use a prompt from the prompt library in an LLM node.
Last modified on September 6, 2026